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1

FATIGUE DESIGN CURVES FOR  

Office of Scientific and Technical Information (OSTI)

FATIGUE DESIGN CURVES FATIGUE DESIGN CURVES FOR 6061-T6 ALUMINUM* G . T . Yahr Engineering Technology Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831-8051 ABSTRACT A request has been made to the ASME Boiler and Pressure Vessel Committee that 6061-T6 aluminum be approved for use in the construction of Class 1 welded nuclear vessels so it can be used for the pressure vessel of the Advanced Neutron Source research reactor. Fatigue design curves with and without mean stress effects have been proposed. A knock-down factor of two is applied to the design curve for evaluation of welds. The basis of the curves is explained. The fatigue design curves are compared to fatigue data from base metal and weldments. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States

2

Development of a Water Environment Fatigue Design Curve for Austenitic Stainless Steels  

SciTech Connect (OSTI)

This note presents the technical basis for a proposed strain-rate and temperature independent fatigue design curve for austenitic stainless steels.

T. R. Leax

2002-12-19T23:59:59.000Z

3

FATIGUE DESIGN CURVES FOR  

Office of Scientific and Technical Information (OSTI)

The ANS is to be a user experimental facility for many scientific fields, including neutron scattering with cold, thermal, and hot neutrons (the most important scientific...

4

Fatigue as a Design Limitation  

Science Journals Connector (OSTI)

...corrodent giving trouble in marine applications such as ships and...reducing fatigue strength in a marine propeller shaft steel. These...chosen both for corrosion and wear resistance and is often used...on the corrosion fatigue of marine propeller shafts. International...

1976-01-01T23:59:59.000Z

5

Estimating Fatigue Curves With the Random FatigueLimit Francis G. Pascual  

E-Print Network [OSTI]

the stress below which an infinite or a specified large number of cycles can be sustained, whichever case, and composite materials and ap­ plied stress is an important input to design­for­reliability processes. This article suggests a practical model to describe the relationship between fatigue life and applied stress

6

Estimating Fatigue Curves With the Random Fatigue-Limit Francis G. Pascual  

E-Print Network [OSTI]

stress is an important input to design-for-reliability processes. This article suggests a practical model large number of cycles can be sustained, whichever case is appropriate. The existence of in nite materials, it is common practice to de ne the \\fatigue strength" to be the stress level below which failure

7

Performance Demonstration Based Probablity of Detection (POD) Curves for Fatigue Cracks in Piping  

SciTech Connect (OSTI)

This paper evaluates non-destructive examination (NDE) detection capabilities for fatigue cracks in piping. Industry performance demonstration initiative (PDI) data for fatigue crack detection were used to develop a matrix of statistically based probability of detection (POD) curves that consider various NDE performance factors. Seven primary performance factors were identified Material, Crack Geometry/Type, NDE Examination Access, NDE Procedure, Examiner Qualification, Pipe Diameter, and Pipe Wall Thickness. A database of 16,181 NDE performance observations, with 18 fields associated with each observation, was created and used to develop statistically based POD curves for 42 stainless steel and 14 carbon steel performance cases. Subsequent comparisons of the POD fits for each of the cases showed that excellent NDE performance for fatigue cracks can be expected for ferritic materials. Very little difference was observed between the POD curves for the 14 carbon steel performance cases considered in this study and NDE performance could therefore be represented by a single POD curve. For stainless steel, very good performance can also be expected for circumferential cracks located on the same side of the weld from which the NDE examination is made. POD depended primarily on component thickness. Three POD curves for stainless steel were prepared. Best estimate and the associated 95% confidence bounds for POD versas through-wall depth logistic regression digital data are provided. Probabilistic fracture mechanics (PFM) calculations were performed to compare best estimate leak probabilities obtained from both the new performance-based POD curves and previous PFM models. This work was performed under joint funding by EPRI and the U.S. Department of Energy (DOE), Office of Nuclear Energy Science and Technologys Nuclear Energy Plant Optimization (NEPO) program.

Gosselin, Stephen R.; Simonen, Fredric A.; Heasler, Patrick G.; Becker, F. L.; Doctor, Steven R.; Carter, R. G.

2005-07-01T23:59:59.000Z

8

PARAMETRIC MODELS FOR ESTIMATING WIND TURBINE FATIGUE LOADS FOR DESIGN  

E-Print Network [OSTI]

loads. #12;2 INTRODUCTION Design constraints for wind turbine structures fall into either extreme load1 PARAMETRIC MODELS FOR ESTIMATING WIND TURBINE FATIGUE LOADS FOR DESIGN Lance Manuel1 Paul S, TX 78712 2 Sandia National Laboratories, Wind Energy Technology Department, Albuquerque, NM 87185

Sweetman, Bert

9

Fatigue threshold R-curves for predicting reliability of ceramics under cyclic loading  

E-Print Network [OSTI]

these materials are typically susceptible to prema- ture failure by subcritical crack propagation owing growth resistance [11] for cracks shorter than the steady-state bridging-zone lengths. Such crack, grain-bridging ceramics, the crack-size dependence of the fatigue threshold during bridging zone

Ritchie, Robert

10

Fatigue Threshold R-Curve Behavior of Grain Bridging Ceramics: Role of Grain Size and Grain-Boundary Adhesion  

E-Print Network [OSTI]

unless they experience environmentally assisted subcritical growth during cyclic loading.7 Fatigue-crack (moist air and dry N2). The fine-grained micro- structure showed higher fatigue thresholds at short crack sizes, while the coarse-grained microstructure demonstrated higher fatigue thresholds at long crack

Kruzic, Jamie

11

Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires  

Science Journals Connector (OSTI)

The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and/or in situ measurements. The versatility of the combined electrochemical/mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues for example the influence of pre-fatigue on the localized corrosion resistance or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

Jenni Kristin Zglinski; Matthias Frotscher

2013-01-01T23:59:59.000Z

12

Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires  

SciTech Connect (OSTI)

The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and/or in situ measurements. The versatility of the combined electrochemical/mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues, for example, the influence of pre-fatigue on the localized corrosion resistance, or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients, which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

Neelakantan, Lakshman [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, 600 036 Chennai (India); Zglinski, Jenni Kristin; Eggeler, Gunther [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); Frotscher, Matthias [Ruhr-Universitaet Bochum, Institute for Materials, 44801 Bochum (Germany); CORTRONIK GmbH, 18119 Rostock-Warnemuende (Germany)

2013-03-15T23:59:59.000Z

13

Strength curves for web crippling design of cold-formed stainless steel hat sections  

Science Journals Connector (OSTI)

Abstract The web crippling design guides are based on empirical adjustments of available test data. These equations differ from the basic concept underpinning most of the other instabilities, the so-called strength curves. This investigation presents a new design approach for web crippling design of stainless steel hat sections based on strength curves controlled by slenderness-based functions ?( ? ). The effects of web crippling on such cross-sections were studied numerically and the obtained results were used to derive the design expressions. Comparisons with tests and FE data, and with design guides show that the proposed design approach provides more accurate web crippling resistance.

M. Bock; E. Real

2014-01-01T23:59:59.000Z

14

Mechanism and estimation of fatigue crack initiation in austenitic stainless steels in LWR environments.  

SciTech Connect (OSTI)

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This report provides an overview of fatigue crack initiation in austenitic stainless steels in LWR coolant environments. The existing fatigue {var_epsilon}-N data have been evaluated to establish the effects of key material, loading, and environmental parameters (such as steel type, strain range, strain rate, temperature, dissolved-oxygen level in water, and flow rate) on the fatigue lives of these steels. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic stainless steels as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are presented. The influence of reactor environments on the mechanism of fatigue crack initiation in these steels is also discussed.

Chopra, O. K.; Energy Technology

2002-08-01T23:59:59.000Z

15

Relationship between design speed and operating speed at horizontal curves on suburban arterials  

E-Print Network [OSTI]

RELATIONSHIP BETWEEN DESIGN SPEED AND OPERATING SPEED AT HORIZONTAL CURVES ON SUBURBAN ARTERIALS A Thesis by CARL BRIAN SHAMBURGER Submitted to the OIIice of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1995 Major Subject: Civil Engineering RELATIONSHIP BETWEEN DESIGN SPEED AND OPERATING SPEED AT HORIZONTAL CURVES ON SUBURBAN ARTERIALS A Thesis by CARL BRIAN SHAMBURGER Submitted to Texas A&M University...

Shamburger, Carl Brian

2012-06-07T23:59:59.000Z

16

Effect of material heat treatment on fatigue crack initiation in austenitic stainless steels in LWR environments.  

SciTech Connect (OSTI)

The ASME Boiler and Pressure Vessel Code provides rules for the design of Class 1 components of nuclear power plants. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify design curves for applicable structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. The existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. Under certain environmental and loading conditions, fatigue lives of austenitic stainless steels (SSs) can be a factor of 20 lower in water than in air. This report presents experimental data on the effect of heat treatment on fatigue crack initiation in austenitic Type 304 SS in LWR coolant environments. A detailed metallographic examination of fatigue test specimens was performed to characterize the crack morphology and fracture morphology. The key material, loading, and environmental parameters and their effect on the fatigue life of these steels are also described. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic SSs as a function of material, loading, and environmental parameters. Two methods for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations are presented.

Chopra, O. K.; Alexandreanu, B.; Shack, W. J.; Energy Technology

2005-07-31T23:59:59.000Z

17

E-Print Network 3.0 - accelerated fatigue testing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

FATIGUE DESIGN METHODS Summary: , caused either by processing or by fatigue, and uses fracture mechanics analyses and tests to check... 2-Fatigue Design Methods 14 ANALYSIS AND...

18

An evaluation of alternative horizontal curve design approaches for rural two-lane highways  

E-Print Network [OSTI]

proposed by Lamm, et al, are: 1) Good: AD s 5' or 2) Fair: 3) Poor: AV? s 9. 7 km/h (6 mi/h), 5 '& PJ'S s 10' or 9. 7 km/h (6 mi/h) + A V? ~ 19. 3 kin/h (12 mi/h), and AO&10' or BV? + 19. 3 km/h (12 nn/h) (18). Foreign Horizontal Curve Design... at the 85th percentile speed. Maximum side friction values for design speeds higher than 90 km/h (55. 9 mi/h) are more than those side fiiction values used by vehicles operating at the 85th percentile speed, due to the concerns of comfort and safety...

Voigt, Anthony Paul

2012-06-07T23:59:59.000Z

19

Projection of fractures in ships for the evaluation of fatigue resistant designs  

E-Print Network [OSTI]

Cracks in ships have been of great concern to the maritime industry for a very long time. The problem is controlled by improving design, minimizing operating stresses and through regular inspections and repairs. The big ...

Hadjiyiannis, Nicholas

2009-01-01T23:59:59.000Z

20

Titanium in fatigue critical military aircraft structure  

SciTech Connect (OSTI)

This paper discusses the effect of fatigue requirements on titanium structure in military aircraft applications, specifically, fighter aircraft. The discussion covers how fatigue affects the design and analysis of detail parts, and how manufacturing processes affect the fatigue performance of titanium structure. Criteria for designing fighter aircraft have evolved from simple strength calculations to extremely complex computer generated analyses involving strength, durability, damage tolerance and fatigue. Fatigue life prediction is an important part of these analyses and dramatically affects the design and weight of fighter aircraft. Manufacturing processes affect fatigue performance both in a positive and negative manner. Designers must allow for the effect of these processes on titanium structure and consider the efficiency and economy of adding processes that increase fatigue life.

Gillespie, F.

1999-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

The impact of modern headlamps on the design of sag vertical curves  

E-Print Network [OSTI]

to the lens. The housing serves as a reflector and lens, and is made of plastic. These lamps may be comprised of different light emitting diode?s (LEDs), high intensity discharge (HID) lamps, and halogen lamps. Halogen headlamps are further comprised... on. HID lamps produce more light compared to halogen lamps (22). Also, HID lamps have a sharper horizontal cut-off beam pattern further reducing the portion of lighted highway on sag curves (25). Light emitting diode is another headlamp...

Gogula, Madhuri

2006-08-16T23:59:59.000Z

22

On the Fatigue Analysis of Wind Turbines  

SciTech Connect (OSTI)

Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. Operational experiences with these large rotating machines indicated that their components (primarily blades and blade joints) were failing at unexpectedly high rates, which led the wind turbine community to develop fatigue analysis capabilities for wind turbines. Our ability to analyze the fatigue behavior of wind turbine components has matured to the point that the prediction of service lifetime is becoming an essential part of the design process. In this review paper, I summarize the technology and describe the ''best practices'' for the fatigue analysis of a wind turbine component. The paper focuses on U.S. technology, but cites European references that provide important insights into the fatigue analysis of wind turbines.

Sutherland, Herbert J.

1999-06-01T23:59:59.000Z

23

Probabilistic fatigue methodology and wind turbine reliability  

SciTech Connect (OSTI)

Wind turbines subjected to highly irregular loadings due to wind, gravity, and gyroscopic effects are especially vulnerable to fatigue damage. The objective of this study is to develop and illustrate methods for the probabilistic analysis and design of fatigue-sensitive wind turbine components. A computer program (CYCLES) that estimates fatigue reliability of structural and mechanical components has been developed. A FORM/SORM analysis is used to compute failure probabilities and importance factors of the random variables. The limit state equation includes uncertainty in environmental loading, gross structural response, and local fatigue properties. Several techniques are shown to better study fatigue loads data. Common one-parameter models, such as the Rayleigh and exponential models are shown to produce dramatically different estimates of load distributions and fatigue damage. Improved fits may be achieved with the two-parameter Weibull model. High b values require better modeling of relatively large stress ranges; this is effectively done by matching at least two moments (Weibull) and better by matching still higher moments. For this purpose, a new, four-moment {open_quotes}generalized Weibull{close_quotes} model is introduced. Load and resistance factor design (LRFD) methodology for design against fatigue is proposed and demonstrated using data from two horizontal-axis wind turbines. To estimate fatigue damage, wind turbine blade loads have been represented by their first three statistical moments across a range of wind conditions. Based on the moments {mu}{sub 1}{hor_ellipsis}{mu}{sub 3}, new {open_quotes}quadratic Weibull{close_quotes} load distribution models are introduced. The fatigue reliability is found to be notably affected by the choice of load distribution model.

Lange, C.H. [Stanford Univ., CA (United States)

1996-05-01T23:59:59.000Z

24

Design and experimental studies of low-cycle fatigue defects in turbine disks of aircraft long-life gas turbine engines  

Science Journals Connector (OSTI)

Some data obtained in the course of numerous studies that include the calculated evaluation of the stressed state and cyclic life of disks up to low-cycle fatigue crack nucleation are presented. Also included ...

N. P. Velikanova; L. R. Botvina; G. P. Okatova

2008-12-01T23:59:59.000Z

25

Fatigue damage behaviors of carbon fiber-reinforced epoxy composites containing nanoclay  

Science Journals Connector (OSTI)

The effects of nanoclay inclusion on cyclic fatigue behavior and residual properties of carbon fiber-reinforced composites (CFRPs) after fatigue have been studied. The tensiontension cyclic fatigue tests are conducted at various load levels to establish the S-N curve. The residual strength and modulus are measured at different stages of fatigue cycles. The scanning electron microscopy (SEM) and scanning acoustic microscopy (SAM) are employed to characterize the underlying fatigue damage mechanisms and progressive damage growth. The incorporation of nanoclay into CFRP composites not only improves the mechanical properties of the composite in static loading, but also the fatigue life for a given cyclic load level and the residual mechanical properties after a given period of cyclic fatigue. The corresponding fatigue damage area is significantly reduced due to nanoclay. Nanoclay serves to suppress and delay delamination damage growth and eventual failure by improving the fiber/matrix interfacial bond and through the formation of nanoclay-induced dimples.

Shafi Ullah Khan; Arshad Munir; Rizwan Hussain; Jang-Kyo Kim

2010-01-01T23:59:59.000Z

26

Research on hydrogen environment fatigue test system and correlative fatigue test of hydrogen storage vessel  

Science Journals Connector (OSTI)

A 70MPa hydrogen environment fatigue test system has been designed and applied in the manufacture of a hydrogen storage vessel. Key equipment is the 80MPa flat steel ribbon wound high pressure hydrogen storage ve...

Rong Li ? ?; Chuan-xiang Zheng ???

2014-02-01T23:59:59.000Z

27

Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR  

SciTech Connect (OSTI)

This report describes the results of investigation on Task 5 of DOE/ASME Materials Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 5 is to collect available creep-fatigue data and study existing creep-fatigue evaluation procedures for Grade 91 steel and Hastelloy XR. Part I of this report is devoted to Grade 91 steel. Existing creep-fatigue data were collected (Appendix A) and analyzed from the viewpoints of establishing a creep-fatigue procedure for VHTR design. A fair amount of creep-fatigue data has been obtained and creep-fatigue phenomena have been clarified to develop design standards mainly for fast breeder reactors. Following this, existing creep-fatigue procedures were studied and it was clarified that the creep-fatigue evaluation procedure of the ASME-NH has a lot of conservatisms and they were analyzed in detail from the viewpoints of the evaluation of creep damage of material. Based on the above studies, suggestions to improve the ASME-NH procedure along with necessary research and development items were presented. Part II of this report is devoted to Hastelloy XR. Existing creep-fatigue data used for development of the high temperature structural design guideline for High Temperature Gas-cooled Reactor (HTGR) were collected. Creep-fatigue evaluation procedure in the design guideline and its application to design of the intermediate heat exchanger (IHX) for High Temperature Engineering Test Reactor (HTTR) was described. Finally, some necessary research and development items in relation to creep-fatigue evaluation for Gen IV and VHTR reactors were presented.

Tai Asayama; Yukio Tachibana

2007-09-30T23:59:59.000Z

28

Learning Curve  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

It is a fundamental human characteristic that a person engaged in a repetitive task will improve his performance over time. If data are gathered on this phenomenon, a curve representing a decrease in effort per unit for repetitive operations can be developed. This phenomenon is real and has a specific application in cost analysis, cost estimating, or profitability studies related to the examination of future costs and confidence levels in an analysis. This chapter discusses the development and application of the learning curve.

1997-03-28T23:59:59.000Z

29

Fatigue monitoring desktop guide  

SciTech Connect (OSTI)

The development of a program for managing material aging (MMG) in the nuclear industry requires a new and different perspective. The classical method for MMG is cycle counting, which has been shown to have limited success. The classical method has been successful in satisfying the ductile condition per the America Society of Mechanical Engineers' (ASME) design criteria. However, the defined material failure mechanism has transformed from through-wall cracking and leakage (ASME) to crack initiation (NUREG-6909). This transformation is based on current industry experience with material degradation early in plant life and can be attributed to fabrication issues and environment concerns where cycle counting has been unsuccessful. This new perspective provides a different approach to cycle counting that incorporates all of the information about the material conditions. This approach goes beyond the consideration of a static analysis and includes a dynamic assessment of component health, which is required for operating plants. This health definition should consider fabrication, inspections, transient conditions and industry operating experience. In addition, this collection of information can be transparent to a broader audience that may not have a full understanding of the system design or the potential causes of early material degradation. This paper will present the key points that are needed for a successful fatigue monitoring desktop guide. (authors)

Woods, K. [InnoTech Engineering Solutions, LLC (United States); Thomas, K. [Nebraska Public Power District (United States)

2012-07-01T23:59:59.000Z

30

Data Treatment and Generation of Fatigue Load Spectrum  

Science Journals Connector (OSTI)

Fatigue reliability assessment is becoming increasingly pertinent in designing mechanical structures and components. For this, it is necessary to identify the probability density function (p.d.f.) defining the sc...

J. J. Xiong; R. A. Shenoi

2011-01-01T23:59:59.000Z

31

Comparison of fatigue analysis approaches for predicting fatigue lives of hot-mix asphalt concrete (HMAC) mixtures  

E-Print Network [OSTI]

) and without (CM) surface energy measurements, and the proposed NCHRP 1-37A 2002 Pavement Design Guide (MEPDG) were comparatively evaluated and utilized to characterize the fatigue resistance of two Texas HMAC mixtures in the laboratory, including...

Walubita, Lubinda F.

2006-08-16T23:59:59.000Z

32

Understanding the fatigue resistance of gamma titanium aluminide  

SciTech Connect (OSTI)

The fatigue limit of Ti-48Al-2Cr in the as HIPed condition was found to be well above the tensile yield strength at room temperature, and was not significantly affected by frequency, microstructure, surface finish or load ratio. On the other hand, a circumferential notch was found to be damaging. The shape of the S-N curve was mostly horizontal, as long as deformation characteristics were not influenced by microstructure or test temperature, and the surface was smooth. While giving due considerations to the fatigue damage a probable problem area for practical applications is identified.

Vaidya, W.V.; Schwalbe, K.H.; Wagner, R. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research

1995-12-31T23:59:59.000Z

33

A Summary of the Fatigue Properties of Wind Turbine Materials  

SciTech Connect (OSTI)

Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. The materials used to construct these machines are subjected to a unique loading spectrum that contains several orders of magnitude more cycles than other fatigue critical structures, e.g., an airplane. To facilitate fatigue designs, a large database of material properties has been generated over the past several years that is specialized to materials typically used in wind turbines. In this paper, I review these fatigue data. Major sections are devoted to the properties developed for wood, metals (primarily aluminum) and fiberglass. Special emphasis is placed on the fiberglass discussion because this material is current the material of choice for wind turbine blades. The paper focuses on the data developed in the U.S., but cites European references that provide important insights.

SUTHERLAND, HERBERT J.

1999-10-07T23:59:59.000Z

34

Ankle mechanical impedance under muscle fatigue .  

E-Print Network [OSTI]

??This study reports the effects of ankle muscle fatigue on ankle mechanical impedance. It suggests that decreasing ankle impedance with muscle fatigue may contribute to (more)

Wang, Shuo, S.B. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

35

Effects of light water reactor coolant environment on the fatigue lives of  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Effects of light water reactor coolant environment on the fatigue lives of Effects of light water reactor coolant environment on the fatigue lives of reactor materials July 8, 2013 A metal component can become progressively degraded, and its structural integrity can be adversely impacted when it is subjected to repeated fluctuating loads, or fatigue loading. Fatigue loadings on nuclear reactor pressure vessel components can occur because of changes in pressure and temperature caused by transients during operation, such as reactor startup or shutdown and turbine trip events. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code recognizes fatigue as a possible cause of failure of reactor materials and provides rules for designing nuclear power plant components to avoid fatigue failures. For various materials, the ASME Code defines the

36

Reversal bending fatigue testing  

SciTech Connect (OSTI)

Embodiments for apparatuses for testing reversal bending fatigue in an elongated beam are disclosed. Embodiments are configured to be coupled to first and second end portions of the beam and to apply a bending moment to the beam and create a pure bending condition in an intermediate portion of the beam. Embodiments are further configured to cyclically alternate the direction of the bending moment applied to the beam such that the intermediate portion of the beam cyclically bends in opposite directions in a pure bending condition.

Wang, Jy-An John; Wang, Hong; Tan, Ting

2014-10-21T23:59:59.000Z

37

High cycle fatigue properties of aluminium foams  

SciTech Connect (OSTI)

Fatigue lifetime measurements have been performed on foamed Al-Mg-Si wrought alloys and Al-Si cast alloys in the high cycle range using an ultrasonic resonance testing method. The porous structure of the material is described by quantitative image analysis of optical micrographs and non destructively by X-ray computer tomography. The static mechanical properties as determined by tensile, compression and bending tests in earlier studies are used for material characterization in this paper. The evaluation of the stress main curves is specified for porous structures to obtain the stiffness and the plateau strength. The influence of the surface skin on the mechanical properties as well as an oscillation behavior during lifetime measurements was studied.

Zettl, B.E.; Stanzl-Tschegg, S.E. [Univ. of Agricultural Sciences (Austria). Inst. of Meteorology and Physics; Gradinger, R. [LKR-Centre of Competence on Light Metals, Ranshofen (Austria); Degischer, H.P. [Vienna Univ. of Technology (Austria). Inst. of Material Science

1998-12-31T23:59:59.000Z

38

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve #12;What are they? How do you make one? #12;DescribesRangeFlows LowFlows 40 % of the time there has been no flow at this site #12;Gather daily flow rate data Load

39

Ankle mechanical impedance under muscle fatigue  

E-Print Network [OSTI]

This study reports the effects of ankle muscle fatigue on ankle mechanical impedance. It suggests that decreasing ankle impedance with muscle fatigue may contribute to an increased probability of ankle injury. If confirmed, ...

Wang, Shuo, S.B. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

40

Modeling of fatigue for cellular materials  

SciTech Connect (OSTI)

Dimensional arguments are used to analyze the fatigue of cellular materials. A modeling describing the fatigue of foams with or without macrocrack is derived and compared to the existing experimental data of cementitious foams and phenolic foams; agreement is good.

Huang, J.S.; Lin, J.Y. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Civil Engineering

1998-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

A method of evaluating Sulphlex mix designs based on the indirect tension test  

E-Print Network [OSTI]

approach to characteriz1ng fatigue life. A procedure for optimizing a mix design was outlined. Design charts for permanent deformation, thermal cracking and fat1gue cracking were presented for Sulphiex binders CR-1 and CR-2 and an asphalt cement (AC-10... of fracture temperature of an asphalt concrete [from Hills and Brien (16)]. . . . . . . 34 22 Failure envelopes for AC-10 crushed limestone mixes of 4 and 7 percent binder content . 37 23 Prediction of thermal cracking using the boundary curve. 39 24...

Richey, Barry Lee

1982-01-01T23:59:59.000Z

42

Predicting the fatigue life of asphalt concrete overlay systems  

E-Print Network [OSTI]

will simply be the da dN "y-intercept" and n is the slope of the curve. From the procedure listed above Saraf found the parameter A to be affected by the viscosity of the asphalt binder used in the mix, a decrease in viscosity gave an increase in A...PREDICTING THE FATIGUE LIFE OF ASPHALT CONCRETE OVERLAY SYSTEMS A Thesis by FREDERICK PHILIP GERMANN Submitted to the Graduate College of Texas A&M University in Partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May...

Germann, Frederick P

1979-01-01T23:59:59.000Z

43

Fatigue analysis for double hull VLCC  

SciTech Connect (OSTI)

This paper presents the procedure and the results of fatigue analysis forming a part of Dynamic Load Approach (DLA) applied for 280,000 DWT double hull VLCC, classed with DLA notation by American Bureau of Shipping. The spectral fatigue analysis is applied to the above vessel, and the fatigue strength is confirmed to be sufficient.

Kawachi, S.; Kushima, T.; Negayama, H.; Shigematsu, K. [Sumitomo Heavy Industries, Ltd., Yokosuka (Japan)

1994-12-31T23:59:59.000Z

44

Peridynamic model for fatigue cracking.  

SciTech Connect (OSTI)

The peridynamic theory is an extension of traditional solid mechanics in which the field equations can be applied on discontinuities, such as growing cracks. This paper proposes a bond damage model within peridynamics to treat the nucleation and growth of cracks due to cyclic loading. Bond damage occurs according to the evolution of a variable called the %22remaining life%22 of each bond that changes over time according to the cyclic strain in the bond. It is shown that the model reproduces the main features of S-N data for typical materials and also reproduces the Paris law for fatigue crack growth. Extensions of the model account for the effects of loading spectrum, fatigue limit, and variable load ratio. A three-dimensional example illustrates the nucleation and growth of a helical fatigue crack in the torsion of an aluminum alloy rod.

Silling, Stewart A.; Abe Askari (Boeing)

2014-10-01T23:59:59.000Z

45

Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended  

Broader source: Energy.gov (indexed) [DOE]

on Assessment of Environmentally--Assisted Fatigue for LWR on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions This report provides an update on the assessment of environmentally-assisted fatigue for light water reactor (LWR) extended service conditions. The report is a deliverable in FY11 under the work package for LWRS under the Advanced Reactor Concepts. Most of the current fleet of aging LWRs were designed using the 1970s version of the ASME Boiler and Pressure Vessels Code, Section III, and are reaching their design lifetime of 30-40 yrs. For economic reasons, the utilities have great interest in extending the operating life of the plants via the Nuclear Regulatory Commission (NRC) licensing renewal application

46

Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended  

Broader source: Energy.gov (indexed) [DOE]

on Assessment of Environmentally--Assisted Fatigue for LWR on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions This report provides an update on the assessment of environmentally-assisted fatigue for light water reactor (LWR) extended service conditions. The report is a deliverable in FY11 under the work package for LWRS under the Advanced Reactor Concepts. Most of the current fleet of aging LWRs were designed using the 1970s version of the ASME Boiler and Pressure Vessels Code, Section III, and are reaching their design lifetime of 30-40 yrs. For economic reasons, the utilities have great interest in extending the operating life of the plants via the Nuclear Regulatory Commission (NRC) licensing renewal application

47

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data there has been no flow at this site #12;Gather daily flow rate data Load data into a spreasheet Sort largest, etc) Calculate percentage of days flow was exceeded: How do you estimate load with given data

48

ROC curves in cost space  

Science Journals Connector (OSTI)

ROC curves and cost curves are two popular ways of visualising classifier performance, finding appropriate thresholds according to the operating condition, and deriving useful aggregated measures such as the area under the ROC curve (AUC) or ... Keywords: Area Under the ROC Curve (AUC), Cost curves, Cost-sensitive evaluation, Kendall tau distance, Operating condition, ROC curves, Ranking performance

Jos Hernndez-Orallo; Peter Flach; Csar Ferri

2013-10-01T23:59:59.000Z

49

Gaussian Curve Summations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Gaussian Curve Summations Gaussian Curve Summations Name: Jay Status: educator Grade: 9-12 Location: MA Country: USA Date: April 2011 Question: I have noticed that when similar Gaussian curves are placed next to each other with 50% overlap between the curves, the summed curves give a constant value equal to the curve peak. Is there a name for this phenomenon, and is it useful in science? Replies: You have to be careful that what appears to be a real mathematical result is analytically true and not a consequence of the scale of the graphing. For example, let us look at two Gaussian curves, G1 = (1/2pi)^1/2 x exp(-1/2(x-1)^2) and G2 = (1/2pi)^1/2 x exp(-1/2(x+1)^2) and their weighted sum Gt(x)= 2 x G1 + 2 x G2. These are two Gaussian curves with mean values (+/-) 1 and standard deviation = 1. That is, they are equally "fat". If you graph Gt(x) between (+/-)0.5, G(t) appears to be a constant very close to unity. However, if you increase the values of 'x' to (+/-)2 you see that the values of Gt = (+/-)0.5. Certainly not a constant. It is a flaw in our scaling of Gt. Or put another way, we are pulling G1 and G2 apart, with no change in the standard deviation. You could make this trickier if you do not hold the standard deviation constant, but make the standard deviation proportional to the mean, so that the curves get "fatter" as you move G1 and G2 apart.

50

f(?) curves: Experimental results  

Science Journals Connector (OSTI)

We study the transition to chaos at the golden and silver means for forced Rayleigh-Bnard (RB) convection in mercury. We present f(?) curves below, at, and above the transition, and provide comparisons to the curves calculated for the one-dimensional circle map. We find good agreement at both the golden and silver means. This confirms our earlier observation that for low amplitude forcing, forced RB convection is well described by the one-dimensional circle map and indicates that the f(?) curve is a good measure of the approach to criticality. For selected subcritical experimental data sets we calculate the degree of subcriticality. We also present both experimental and calculated results for f(?) in the presence of a third frequency. Again we obtain agreement: The presence of random noise or a third frequency narrows the right-hand (negative q) side of the f(?) curve. Subcriticality results in symmetrically narrowed curves. We can also distinguish these cases by examining the power spectra and Poincar sections of the time series.

James A. Glazier; Gemunu Gunaratne; Albert Libchaber

1988-01-15T23:59:59.000Z

51

Seismic design technology for Breeder Reactor structures. Volume 3: special topics in reactor structures  

SciTech Connect (OSTI)

This volume is divided into six chapters: analysis techniques, equivalent damping values, probabilistic design factors, design verifications, equivalent response cycles for fatigue analysis, and seismic isolation. (JDB)

Reddy, D.P. (ed)

1983-04-01T23:59:59.000Z

52

ROC curves for regression  

Science Journals Connector (OSTI)

Receiver Operating Characteristic (ROC) analysis is one of the most popular tools for the visual assessment and understanding of classifier performance. In this paper we present a new representation of regression models in the so-called regression ROC ... Keywords: Asymmetric loss, Cost-sensitive regression, Error variance, MSE decomposition, Operating condition, ROC Curves

Jos Hernndez-Orallo

2013-12-01T23:59:59.000Z

53

DOE/MSU composite material fatigue database: Test methods, materials, and analysis  

SciTech Connect (OSTI)

This report presents a detailed analysis of the results from fatigue studies of wind turbine blade composite materials carried out at Montana State University (MSU) over the last seven years. It is intended to be used in conjunction with the DOE/MSU composite Materials Fatigue Database. The fatigue testing of composite materials requires the adaptation of standard test methods to the particular composite structure of concern. The stranded fabric E-glass reinforcement used by many blade manufacturers has required the development of several test modifications to obtain valid test data for materials with particular reinforcement details, over the required range of tensile and compressive loadings. Additionally, a novel testing approach to high frequency (100 Hz) testing for high cycle fatigue using minicoupons has been developed and validated. The database for standard coupon tests now includes over 4,100 data points for over 110 materials systems. The report analyzes the database for trends and transitions in static and fatigue behavior with various materials parameters. Parameters explored are reinforcement fabric architecture, fiber content, content of fibers oriented in the load direction, matrix material, and loading parameters (tension, compression, and reversed loading). Significant transitions from good fatigue resistance to poor fatigue resistance are evident in the range of materials currently used in many blades. A preliminary evaluation of knockdowns for selected structural details is also presented. The high frequency database provides a significant set of data for various loading conditions in the longitudinal and transverse directions of unidirectional composites out to 10{sup 8} cycles. The results are expressed in stress and strain based Goodman Diagrams suitable for design. A discussion is provided to guide the user of the database in its application to blade design.

Mandell, J.F.; Samborsky, D.D. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemical Engineering

1997-12-01T23:59:59.000Z

54

Accelerating Fatigue Testing for Cu Ribbon Interconnects (Presentation)  

SciTech Connect (OSTI)

This presentation describes fatigue experiments and discusses dynamic mechanical loading for Cu ribbon interconnects.

Bosco, N.; Silverman, T.; Wohlgemuth , J.; Kurtz, S.; Inoue, M.; Sakurai, K.; Shioda, T.; Zenkoh, H.; Miyashita, M.; Tadanori, T.; Suzuki, S.

2013-05-01T23:59:59.000Z

55

Elevated temperature biaxial fatigue. Final Report  

SciTech Connect (OSTI)

A 3 year experimental program for studying elevated temperature biaxial fatigue of a nickel based alloy Hastelloy-X has been completed. A new high temperature fatigue test facility with unique capabilities has been developed. Effort was directed toward understanding multiaxial fatigue and correlating the experimental data to the existing theories of fatigue failure. The difficult task of predicting fatigue lives for nonproportional loading was used as an ultimate test for various life prediction methods being considered. The primary means of reaching improved understanding were through several critical nonproportional loading experiments. The direction of cracking observed on failed specimens was also recorded and used to guide the development of the theory. Cyclic deformation responses were permanently recorded digitally during each test. It was discovered that the cracking mode switched from primarily cracking on the maximum shear planes at room temperature to cracking on the maximum normal strain planes at 649 C. In contrast to some other metals, loading path in nonproportional loading had little effect on fatigue lives. Strain rate had a small effect on fatigue lives at 649 C. Of the various correlating parameters the modified plastic work and octahedral shear stress were the most successful.

Jordan, E.H.

1985-10-01T23:59:59.000Z

56

Digital Jordan Curve Theorems Christer O. Kiselman  

E-Print Network [OSTI]

Digital Jordan Curve Theorems Christer O. Kiselman's digital Jordan curve theorem states that the complement of a Jordan curve in the digital plane of Jordan curves. 1 Introduction The classical Jordan curve theorem says that the complement

Kiselman, Christer

57

Transfinite partitions of Jordan curves  

E-Print Network [OSTI]

The w-asymmetry induced by transfinite partitions makes it impossible for Jordan curves to have an infinite length.

Antonio Leon

2006-08-21T23:59:59.000Z

58

Contact fatigue : life prediction and palliatives  

E-Print Network [OSTI]

Fretting fatigue is defined as damage resulting from small magnitude (0.5-50 microns) displacement between contacting bodies where at least one of the bodies has an applied bulk stress. The applicability and limits of a ...

Conner, Brett P. (Brett Page), 1975-

2002-01-01T23:59:59.000Z

59

Actuation Fatigue of Shape Memory Alloys  

E-Print Network [OSTI]

). Schick (2009) conducted the rst study of the actuation fatigue of specimens produced from plate material at Texas A&M [34]. In this work, at-sheet fatigue specimens were machined from Ni60Ti40 (wt. %) plate using electro-discharge ma- chining (EDM... accuracy of strain measurements, and reduced cross-sectional area to accelerate cycling rates [36]. Specimens were produced using electro-discharge machining (EDM). All specimens were heat treated, polished and tested. 1. Specimen Geometry Flat...

Calhoun, Christopher

2012-07-16T23:59:59.000Z

60

Sensitivity of Solder Joint Fatigue to Sources of Variation in Advanced Vehicular Power Electronics Cooling  

SciTech Connect (OSTI)

This paper demonstrates a methodology for taking variation into account in thermal and fatigue analyses of the die attach for an inverter of an electric traction drive vehicle. This method can be used to understand how variation and mission profile affect parameters of interest in a design. Three parameters are varied to represent manufacturing, material, and loading variation: solder joint voiding, aluminum nitride substrate thermal conductivity, and heat generation at the integrated gate bipolar transistor. The influence of these parameters on temperature and solder fatigue life is presented. The heat generation loading variation shows the largest influence on the results for the assumptions used in this problem setup.

Vlahinos, A.; O'Keefe, M.

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Application of measured loads to wind turbine fatigue and reliability analysis  

SciTech Connect (OSTI)

Cyclic loadings produce progressive damage that can ultimately result in wind turbine structural failure. There are many issues that must be dealt with in turning load measurements into estimates of component fatigue life. This paper deals with how the measured loads can be analyzed and processed to meet the needs of both fatigue life calculations and reliability estimates. It is recommended that moments of the distribution of rainflow-range load amplitudes be calculated and used to characterize the fatigue loading. These moments reflect successively more detailed physical characteristics of the loading (mean, spread, tail behavior). Moments can be calculated from data samples and functional forms can be fitted to wind conditions, such as wind speed and turbulence intensity, with standard recession techniques. Distributions of load amplitudes that accurately reflect the damaging potential of the loadings can be estimated from the moments at any, wind condition of interest. Fatigue life can then be calculated from the estimated load distributions, and the overall, long-term, or design spectrum can be generated for any particular wind-speed distribution. Characterizing the uncertainty in the distribution of cyclic loads is facilitated by using a small set of descriptive statistics for which uncertainties can be estimated. The effects of loading parameter uncertainty can then be transferred to the fatigue life estimate and compared with other uncertainties, such as material durability.

Veers, P.S. [Sandia National Labs., Albuquerque, NM (United States); Winterstein, S.R. [Stanford Univ., CA (United States)

1997-01-01T23:59:59.000Z

62

A systems science approach to fatigue management inresearch and health care  

Science Journals Connector (OSTI)

Abstract The purpose of this article was to highlight innovative analytic approaches in symptom science. Complex systems modeling is discussed using fatigue as an example. Fatigue is a common symptom among individuals of any age. It can be acute or chronic, and it can vary across the day and on weekends compared with weekdays. Fatigue can overlap with other symptoms, has many dimensions, and impacts daily function as well as society at large. With the complexities surrounding symptom science, innovative models are needed to advance our understanding of factors within the person, contextual and situational factors, and workplace or health care system factors that impact the symptom experience. Advances in methodologies, such as complex systems modeling, allow for more innovative methods to study the complexities of the symptom experience, design better ways to intervene and manage symptoms, and ultimately improve outcomes related to symptom management, quality of life, and health care utilization.

Kathryn A. Lee; Oliwier Dziadkowiec; Paula Meek

2014-01-01T23:59:59.000Z

63

A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water  

Broader source: Energy.gov (indexed) [DOE]

A Review of Stress Corrosion Cracking/Fatigue Modeling for Light A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water Reactor Cooling System Components A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water Reactor Cooling System Components In the United States currently there are approximately 104 operating light water reactors. Of these, 69 are pressurized water reactors (PWRs) and 35 are boiling water reactors (BWRs). In 2007, the 104 light-water reactors (LWRs) in the United States generated approximately 100 GWe, equivalent to 20% of total US electricity production. Most of the US reactors were built before 1970 and the initial design lives of most of the reactors are 40 years. It is expected that by 2030, even those reactors that have received 20-year life extension license from the US Nuclear Regulatory Commission

64

Blade root attachment evaluation low-cycle fatigue estimates based on probabilistic approach  

SciTech Connect (OSTI)

When utilities purchase replacement blades from a manufacturer, the machining tolerances in the root attachment and the material fatigue properties are a major quality concern. These factors can have significant impact on the low-cycle fatigue life. For any replacement blades, the primary concern is to minimize the risk of an in-service failure. However, excessively conservative acceptance criteria would unnecessarily drive up the unit price for the replacement blades. Acceptance criteria with estimates of associated risks of in-service failure are therefore needed for each specific blade design based on the expected operating environment, material, and service life. In the work presented herein, a probabilistic model to estimate LCF in the blade root attachment is presented. The approach is demonstrated using stresses and material fatigue properties for a representative LP last stage blade of a steam turbine. The LCF life estimates obtained using the proposed approach show good correlation with field experience.

Sarlashkar, A.V.; Lam, T.C.T. [Stress Technology Inc., Rochester, NY (United States); McCloskey, T.H. [Electric Power Research Inst., Palo Alto, CA (United States)

1996-12-31T23:59:59.000Z

65

Fatigue crack propagation in a quasi one-dimensional elasto-plastic model  

E-Print Network [OSTI]

Fatigue crack advance induced by the application of cyclic quasistatic loads is investigated both numerically and analytically using a lattice spring model. The system has a quasi-one-dimensional geometry, and consists in two symmetrical chains that are pulled apart, thus breaking springs which connect them, and producing the advance of a crack. Quasistatic crack advance occurs as a consequence of the plasticity included in the springs which form the chains, and that implies a history dependent stress-strain curve for each spring. The continuous limit of the model allows a detailed analytical treatment that gives physical insight of the propagation mechanism. This simple model captures key features that cause well known phenomenology in fatigue crack propagation, in particular a Paris-like law of crack advance under cyclic loading, and the overload retardation effect.

Toms M. Guozden; Eduardo A. Jagla

2012-06-27T23:59:59.000Z

66

An experimental study on the effects of compressive stress on the fatigue crack growth of low-alloy steel  

SciTech Connect (OSTI)

A series of fatigue crack growth rate tests was conducted in order to study effects of negative stress ratio on fatigue crack growth rate of low-alloy steel in air. Four-point bend specimens were used to simulate linear stress distributions typical of pressure vessel applications. This type of testing adds to knowledge on negative stress ratio effects for low-alloy steels obtained in the past from uniform tension-compression tests. Applied bending stress range was varied over twice the yield strength. Load control was used for tests for which the stress range was less than twice the yield strength and deflection control was used for the higher stress range tests. Crack geometries were both short and long fatigue cracks started at notches and tight fatigue cracks for which crack closure could occur over the full crack face. Results are presented in terms of the stress intensity factor ratio R = K{sub MIN}/K{sub MAX}. The negative R-ratio test results were correlated to an equation of the form da/dN = C[{Delta}K/(A-R)]{sup n}, where A, C, and n are curve fitting parameters. It was found that effects of negative R-ratio on fatigue crack growth rates for even the high stress range tests could be bounded by correlating the above equation to only positive R-ratio test results and extending the resulting equation into the negative R-ratio regime.

Jones, D.P.; Hoppe, R.G. [Westinghouse Electric Corp., West Mifflin, PA (United States). Bettis Atomic Power Lab.; Hechmer, J.L. [Babcock and Wilcox Co., Barberton, OH (United States); James, B.A. [Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgy

1993-12-01T23:59:59.000Z

67

Rolling Contact Fatigue of Ceramics  

SciTech Connect (OSTI)

High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

Wereszczak, Andrew A [ORNL; Wang, W. [Bournemouth University, Bournemouth, United Kingdom; Wang, Y. [Bournemouth University, Bournemouth, United Kingdom; Hadfield, M. [Bournemouth University, Bournemouth, United Kingdom; Kanematsu, W. [National Institute of Advanced Industrial Science and Technology, Japan; Kirkland, Timothy Philip [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville

2006-09-01T23:59:59.000Z

68

Design  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Design Design of a Multithreaded Barnes-Hut Algorithm for Multicore Clusters Technical Report Junchao Zhang and Babak Behzad Department of Computer Science, University of Illinois at Urbana-Champaign {jczhang, bbehza2}@illinois.edu Marc Snir Department of Computer Science, University of Illinois at Urbana-Champaign and MCS Division, Argonne National Laboratory snir@anl.gov Abstract We describe in this paper an implementation of the Barnes-Hut al- gorithm on multicore clusters. Based on a partitioned global ad- dress space (PGAS) library, the design integrates intranode mul- tithreading and internode one-sided communication, exemplifying a PGAS + X programming style. Within a node, the computation is decomposed into tasks (subtasks), and multitasking is used to hide network latency. We study the tradeoffs between locality in private caches and locality in shared caches

69

Fatigue Enhancement of Undersized, Drilled Crack-Arrest Holes  

E-Print Network [OSTI]

Fatigue cracks occur in steel bridges from repeated loads. If allowed to continue to grow, eventually the fatigue cracks will require either expensive repairs or reduction of traffic loads on the bridge, or they may lead ...

Simmons, Gary Gene

2013-12-31T23:59:59.000Z

70

Characterization of Fatigue Cracking and Healing of Asphalt Mixtures  

E-Print Network [OSTI]

Fatigue cracking is one of the most common distresses of asphalt pavements, whereas healing is a counter process to cracking which alleviates cracking damage and extends fatigue life of asphalt pavements. Most of existing methods to characterize...

Luo, Xue

2012-07-16T23:59:59.000Z

71

Fatigue behavior of alpha-zirconium phosphate/epoxy nanocomposites  

E-Print Network [OSTI]

Fatigue crack growth in -Zirconium phosphate/epoxy nanocomposites was investigated. A new fatigue testing technique was implemented for miniature samples. Two different methods ?strength of materials and Rayleigh-Ritz - were used in determining...

Varadharajan, Balaji R.

2006-04-12T23:59:59.000Z

72

Photo-Electric Thresholds and Fatigue  

Science Journals Connector (OSTI)

Photo-electric fatigue.Using elements of the highest purity, clean surfaces were prepared, in a vacuum of the order of 10-6 mm of Hg, by means of an electromagnetic filing device. A linear relation was found between the logarithm of the photo-electric current and the logarithm of the time elapsed since polishing the specimen. The rate of fatigue depends upon the element used and the factors which produce fatigue and, for a given substance, increases numerically as the threshold is approached. Increasing the pressure increases the rate of fatigue. The action of light has a negligible effect.Photo-electric thresholds.The values for Ca, Fe, Co, Ni, Cu, Zn, and Ge are, respectively, 4475, 3155, 3165, 3040, 2955, 3180, and 2880A. Within a period of several hours at least photo-electric fatigue causes no change in these values when a high vacuum is used. Evidence for a shift towards shorter wave-lengths is obtained for lower vacua.The "patch" theory.A theory in which contamination takes place at discrete areas of the surface of the element is proposed to account for the experimental facts obtained.

George B. Welch

1928-10-01T23:59:59.000Z

73

Reversible Bending Fatigue Testing on Zry-4 Surrogate Rods  

SciTech Connect (OSTI)

Testing high-burnup spent nuclear fuel (SNF) presents many challenges in areas such as specimen preparation, specimen installation, mechanical loading, load control, measurements, data acquisition, and specimen disposal because these tasks are complicated by the radioactivity of the test specimens. Research and comparison studies conducted at Oak Ridge National Laboratory (ORNL) resulted in a new concept in 2010 for a U-frame testing setup on which to perform hot-cell reversible bending fatigue testing. Subsequently, the three-dimensional finite element analysis and the engineering design of components were completed. In 2013 the ORNL team finalized the upgrade of the U-frame testing setup and the integration of the U-frame setup into a Bose dual linear motor test bench to develop a cyclic integrated reversible-bending fatigue tester (CIRFT). A final check was conducted on the CIRFT test system in August 2013, and the CIRFT was installed in the hot cell in September 2013 to evaluate both the static and dynamic mechanical response of SNF rods under simulated loads. The fatigue responses of Zircaloy-4 (Zry-4) cladding and the role of pellet pellet and pellet clad interactions are critical to SNF vibration integrity, but such data are not available due to the unavailability of an effective testing system. While the deployment of the developed CIRFT test system in a hot cell will provide the opportunity to generate the data, the use of a surrogate rod has proven quite effective in identifying the underlying deformation mechanism of an SNF composite rod under an equivalent loading condition. This paper presents the experimental results of using surrogate rods under CIRFT reversible cyclic loading. Specifically, monotonic and cyclic bending tests were conducted on surrogate rods made of a Zry-4 tube and alumina pellet inserts, both with and without an epoxy bond.

Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Bevard, Bruce Balkcom [ORNL; Howard, Rob L [ORNL

2014-01-01T23:59:59.000Z

74

Failure by fracture and fatigue in "NANO" and "BIO" materials  

E-Print Network [OSTI]

to cyclic fatigue and subcritical crack growth, micron-scalemoisture-assisted subcritical crack growth in this oxide

Ritchie, R.O.; Muhlstein, C.L.; Nalla, R.K.

2003-01-01T23:59:59.000Z

75

Study of the Fatigue Life of Steel Catenary Risers in Interaction with the Seabed  

E-Print Network [OSTI]

1.1. Examples of riser configurations (DNV-OS-F201) .......................... 2 Figure 1.2. Sample of S-N curve (from DNV-RP-C203) .................................... 6 Figure 1.3. Schematic of flex joint (API RP 2RD... of the riser where it is attached to the vessel, and the TDZ where it contacts the seabed. Several methods are employed in order to reduce the fatigue damage in risers. Using flex joints ?which consist of one or more metal-elastomer bearings ? may reduce...

Nakhaee, Ali

2011-02-22T23:59:59.000Z

76

Associations between infections and fatigue in a Dutch working population: Results of the Maastricht Cohort Study on Fatigue at Work  

Science Journals Connector (OSTI)

The relationship between fatigue and common infections was further explored, as part of a 3 year prospective cohort study on Fatigue at Work. The current study is based on seven successive questionnaires, cove...

D.C.L. Mohren; G.M.H. Swaen; I.J. Kant; P.J.A. Borm

2001-01-01T23:59:59.000Z

77

Fatigue Reliability-based Inspection and Maintenance Planning of Gearbox Components in Wind Turbine Drivetrains  

Science Journals Connector (OSTI)

Abstract This paper introduces a reliability-based maintenance plan for wind turbine gearbox components. The gears and bearings are graded based on their fatigue damage and a maintenance map is developed to focus on those components with higher probability of fatigue failure and lower level of reliability. The main aim of this paper is to propose a method for developing the vulnerability map which can be used by maintenance teams to identify the components with lower reliabilities. The fatigue damage for gears and bearings are calculated at rated wind speed by the SN curve approach. The load duration distribution (LDD) method is used to obtain the stress range cycles for gears and load range cycles for bearings from the load and load effect time series obtained from a global response analysis. During routine inspection and maintenance, the vulnerability map can be used to find the faulty component by inspecting those with highest probability of failure rather than examining all gears and bearings. Such maps can be used for fault detection during routine maintenance and can reduce the down time and efforts of maintenance team to identify the source of problem. The proposed procedure is exemplified by a 750kW gearbox and a vulnerability map is developed for this case study gearbox.

Amir Rasekhi Nejad; Zhen Gao; Torgeir Moan

2014-01-01T23:59:59.000Z

78

CREEP AND CREEP-FATIGUE OF ALLOY 617 WELDMENTS  

SciTech Connect (OSTI)

The Very High Temperature Reactor (VHTR) Intermediate Heat Exchanger (IHX) may be joined to piping or other components by welding. Creep-fatigue deformation is expected to be a predominant failure mechanism of the IHX1 and thus weldments used in its fabrication will experience varying cyclic stresses interrupted by periods of elevated temperature deformation. These periods of elevated temperature deformation are greatly influenced by a materials creep behavior. The nickel-base solid solution strengthened alloy, Alloy 617, is the primary material candidate for a VHTR-type IHX, and it is expected that Alloy 617 filler metal will be used for welds. Alloy 617 is not yet been integrated into Section III of the Boiler and Pressure Vessel Code, however, nuclear component design with Alloy 617 requires ASME (American Society of Mechanical Engineers) Code qualification. The Code will dictate design for welded construction through significant performance reductions. Despite the similar compositions of the weldment and base material, significantly different microstructures and mechanical properties are inevitable. Experience of nickel alloy welds in structural applications suggests that most high temperature failures occur at the weldments or in the heat-affected zone. Reliably guarding against this type of failure is particularly challenging at high temperatures due to the variations in the inelastic response of the constituent parts of the weldment (i.e., weld metal, heat-affected zone, and base metal) [ref]. This work focuses on the creep-fatigue behavior of nickel-based weldments, a need noted during the development of the draft Alloy 617 ASME Code Case. An understanding of Alloy 617 weldments when subjected to this important deformation mode will enable determination of the appropriate design parameters associated with their use. Specifically, the three main areas emphasized are the performance reduction due to a weld discontinuity in terms of the reduced number of the cycles to failure and whether a saturation in reduced cycle life with increased hold times is observed, the microstructural stability over long cycle times, and finally, the location of the generated weldment data on a creep-fatigue damage diagram (D-diagram).

Wright, Jill; Carroll, Laura; Wright, Richard

2014-08-01T23:59:59.000Z

79

Quantifying the Thermal Fatigue of CPV Modules  

SciTech Connect (OSTI)

A method is presented to quantify thermal fatigue in the CPV die-attach from meteorological data. A comparative; study between cities demonstrates a significant difference in the accumulated damage. These differences are most; sensitive to the number of larger (?T) thermal cycles experienced for a location. High frequency data (<1/min) may; be required to most accurately employ this method.

Bosco, N.; Kurtz, S.

2011-02-01T23:59:59.000Z

80

PREDICTORS OF POST-STROKE FATIGUE  

E-Print Network [OSTI]

PURPOSE: Fatigue is a commonly neglected issue despite the high incidence rate reported in people with chronic stroke. It can impact daily functions and quality of life and has been linked with a higher mortality rate after stroke because of its...

Tseng, Benjamin Yichen

2009-01-29T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Damage and fatigue Continuum damage mechanics modeling  

E-Print Network [OSTI]

-CL?S : endommagement, fatigue, métaux, béton, élastomères, roche REGC ­ 10/2006. Geomechanics in energy production, pages 849 to 877 #12;850 REGC ­ 10/2006. Geomechanics in energy production 1. Introduction Continuum

82

Progress Report on Alloy 617 Isochronous Stress-Strain Curves  

SciTech Connect (OSTI)

Isochronous stress-strain curves for Alloy 617 up to a temperature of 1000C will be required to qualify the material for elevated temperature design in Section III, Division 1, Subsection NH of the ASME Boiler and Pressure Vessel Code. Several potential methods for developing these curves are reviewed in this report. It is shown that in general power-law creep is the rate controlling deformation mechanism for a wide range of alloy heats, test temperatures and stresses. Measurement of the strain rate sensitivity of Alloy 617 indicates that the material is highly strain rate sensitive in the tensile deformation range above about 750C. This suggests that the concept of a hot tensile curve as a bounding case on the isochronous stress-strain diagrams is problematic. The impact of strain rate on the hot tensile curves is examined and it is concluded that incorporating such a curve is only meaningful if a single tensile strain rate (typically the ASTM standard rate of 0.5%/min) is arbitrarily defined. Current experimentally determined creep data are compared to isochronous stress-strain curves proposed previously by the German programs in the 1980s and by the 1990 draft ASME Code Case. Variability in how well the experimental data are represented by the proposed design curves that suggests further analysis is necessary prior to completing a new draft Code Case.

Jill K. Wright; Richard N. Wright; Nancy J. Lybeck

2014-03-01T23:59:59.000Z

83

Mean Stress and Environmental Effects on Fatigue in Type 304 Stainless Steel  

SciTech Connect (OSTI)

Fatigue life tests were performed in air on Type 304 stainless steel (304 SS) to establish the effect of mean stress under both load control and strain control. An apparent reduction of up to 26% in strain-amplitude occurred in the low and intermediate cycle regime (< 10{sup 8} cycles) for a mean stress of 138 Mpa. A quantitative description of mean stress effects using the Smith-Watson-Topper equivalent strain parameter was developed, which incorporates mean stress through the maximum stress. This description provided a tighter fit to the data, and allowed separation of mean stress and cold work effects. With this separation, the effect of mean stress was reduced to 12% decrease in strain amplitude at 138 Mpa. The stress-life curve apparently increased with increasing mean stress, due to the significant work hardening that occurred in tests with high mean stresses, especially under load control. Tests were performed on double-edge notched specimens of 304 SS in air and low oxygen water at 288 C. The elastically calculated increase in the notch tip stress accounted within 10% for the fatigue life reductions for a K{sub t} = 4.8 notch, but was 38% conservative for a K{sub t} = 8.8 notch. Fatigue crack initiation lives (defined as an 0.127 mm crack) in low oxygen water at 288 C were reduced by a factor of four to eight on cycles over those in air. Crack growth occurred throughout most of the fatigue ''initiation'' life. The increase in crack growth rate of 304 SS in water appears to be large enough to explain the reduced ''initiation'' life in this environment.

Kandra, J.T.; Leax, T.R.; Wire, G.L.

1999-04-01T23:59:59.000Z

84

The marine biodiversity curve is an icon of paleobiology. The familiar curve shows  

E-Print Network [OSTI]

The marine biodiversity curve is an icon of paleobiology. The familiar curve shows increasing. Although the iconic diversity curve might be specious, the pattern of Evolutionary Faunas

Waxman, David

85

Use of CFRP Overlays to Repair Fatigue Damage in Steel Bridge Girders and Components  

E-Print Network [OSTI]

Fatigue damage in steel girder bridges built prior to the mid-1980s is common due to distortion-induced fatigue. Different repair techniques have been developed and implemented to retrofit bridges of this era with existing fatigue damage...

Gangel, Regan Elisabeth

2012-05-31T23:59:59.000Z

86

Difference between High- and Low-Stress Fatigue  

Science Journals Connector (OSTI)

... below the fatigue limit. Crack initiation may thus be considered as a consequence of surface roughening within broad slip bands7'8.

N. E. FROST

1961-11-04T23:59:59.000Z

87

Residual Stresses for Structural Analysis and Fatigue Life Prediction...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Analysis and Fatigue Life Prediction in Vehicle Components: Success stories from the High Temperature Materials Laboratory (HTML) User Program Residual Stresses for Structural...

88

E-Print Network 3.0 - actual fatigue usage Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2007 Published online 18 June 2007 Keywords: Bone Dentin Fatigue Mineralized tissues Fracture Life... in the fatigue and fracture of mineralized tissues, and to discover how these...

89

Nonlinear acoustics: A transition from laboratory to a practical fatigue assessment tool.  

Science Journals Connector (OSTI)

The ultrasonicsecond harmonic generation technique measuring the nonlinearity parameter has been developed and used in laboratories for several decades throughout the world. Many students and visiting scholars from numerous countries devoted their passions at the physical acoustics laboratories led by Dr. Mack Breazeale for 50 years. During that period of time nonlinear elastic properties of single crystals polycrystallinealloys superconductors ceramics and composites were measured. New measurement systems and techniques were also developed to understand temperature dependent linear and nonlinear elastic behaviors of these materials over a temperature range from the liquid helium to Curie temperatures of piezoelectricceramics. It took years of research and development efforts with a persistent funding before a practical fatigue damage measurement technique was finally developed. The transition from a rack full of equipment to a portable fatigue damage measurement system a continuous iteration process was inevitable. The current system specifically designed for steam turbine blades fatigue inspections consists of a probe fixture and an industrial grade lunch?box computer with custom designed signal processing cards.

Jeong?Kwan Na

2010-01-01T23:59:59.000Z

90

Wind turbine blade fatigue tests: lessons learned and application to SHM system development  

SciTech Connect (OSTI)

This paper presents experimental results of several structural health monitoring (SHM) methods applied to a 9-meter CX-100 wind turbine blade that underwent fatigue loading. The blade was instrumented with piezoelectric transducers, accelerometers, acoustic emission sensors, and foil strain gauges. It underwent harmonic excitation at its first natural frequency using a hydraulically actuated resonant excitation system. The blade was initially excited at 25% of its design load, and then with steadily increasing loads until it failed. Various data were collected between and during fatigue loading sessions. The data were measured over multiple frequency ranges using a variety of acquisition equipment, including off-the-shelf systems and specially designed hardware developed by the authors. Modal response, diffuse wave-field transfer functions, and ultrasonic guided wave methods were applied to assess the condition of the wind turbine blade. The piezoelectric sensors themselves were also monitored using a sensor diagnostics procedure. This paper summarizes experimental procedures and results, focusing particularly on fatigue crack detection, and concludes with considerations for implementing such damage identification systems, which will be used as a guideline for future SHM system development for operating wind turbine blades.

Taylor, Stuart G. [Los Alamos National Laboratory; Farinholt, Kevin M. [Los Alamos National Laboratory; Jeong, Hyomi [Chonbuk National University, Korea; Jang, JaeKyung [Chonbuk National University, Korea; Park, Gyu Hae [Los Alamos National Laboratory; Todd, Michael D. [Los Alamos National Laboratory; Farrar, Charles R. [Los Alamos National Laboratory; Ammerman, Curtt N. [Los Alamos National Laboratory

2012-06-28T23:59:59.000Z

91

Ris0-R-991(EN) Fatigue Performance of Copper and  

E-Print Network [OSTI]

Ris0-R-991(EN) inn DK9700117 Fatigue Performance of Copper and Copper alloys before and after ARE MISSING IN THE ORIGINAL DOCUMENT #12;Fatigue Performance of Copper and Copper alloys before and after performance of pure copper of the oxygen free, high conductivity (OFHC) grade and two copper alloys (Cu

92

Fracture toughness and fatigue crack growth characteristics of nanotwinned copper  

E-Print Network [OSTI]

fracture and subcritical fatigue crack growth life. Possible mechanistic origins of these trends and the resistance to stable subcritical crack growth under mono- tonic and cyclic loading, especially at lowerFracture toughness and fatigue crack growth characteristics of nanotwinned copper A. Singh a,1 , L

Suresh, Subra

93

A Discrete Gust Model for Use in the Design of Wind Energy Conversion Systems  

Science Journals Connector (OSTI)

Discrete gust models, although idealizations of actual atmospheric conditions, are useful for engineering design. For fatigue design, these models must be representative of the conditions a structure or vehicle will experience on a continuous ...

Walter Frost; Robert E. Turner

1982-06-01T23:59:59.000Z

94

Kinetic roughening on curved interfaces  

E-Print Network [OSTI]

Stochastic growth phenomena on curved interfaces have not been explored in so much detail as their planar counterparts. The independence of the interface macroscopic shape on kinetic roughening has been occasionally assumed, but however, this fact can not be considered as universal. Stochastic partial differential equations on curved interfaces present dynamical and morphological properties that are completely different from their planar equivalents. Herein we will concentrate on equations which planar counterparts are linear. The fundamental differences are the loss of correlation of the interface through time for models showing sub-ballistic propagation of the correlations and the irrelevance of the noise in two and higher dimensional settings. We analyze some of these processes in detail, exploring why these consequences arise, and show that they tend to appear irrespective of the particular metric, provided that it is not Euclidean. Models showing a super-ballistic propagation of correlations present a fl...

Escudero, Carlos

2008-01-01T23:59:59.000Z

95

Optical conductivity of curved graphene  

E-Print Network [OSTI]

We compute the optical conductivity for an out-of-plane deformation in graphene using an approach based on solutions of the Dirac equation in curved space. Different examples of periodic deformations along one direction translates into an enhancement of the optical conductivity peaks in the region of the far and mid infrared frequencies for periodicities $\\sim100\\,$nm. The width and position of the peaks can be changed by dialling the parameters of the deformation profiles. The enhancement of the optical conductivity is due to intraband transitions and the translational invariance breaking in the geometrically deformed background. Furthemore, we derive an analytical solution of the Dirac equation in a curved space for a general deformation along one spatial direction. For this class of geometries, it is shown that curvature induces an extra phase in the electron wave function, which can also be explored to produce interference devices of the Aharonov-Bohm type.

A. J. Chaves; T. Frederico; O. Oliveira; W. de Paula; M. C. Santos

2014-05-01T23:59:59.000Z

96

1000ton testing machine for cyclic fatigue tests of materials at liquid nitrogen temperatures  

SciTech Connect (OSTI)

One of the main tasks of superconductive magnets R and D is to determine the mechanical and fatigue properties of structural materials and the critical design elements in the cryogenic temperature range. This paper describes a new facility built based on the industrial 1000-ton (10 MN) testing machine Schenk PC10.0S. Special equipment was developed to provide the mechanical and cyclic tensile fatigue tests of large-scale samples at the liquid nitrogen temperature and in a given load range. The main feature of the developed testing machine is the cryostat, in which the device converting a standard compression force of the testing machine to the tensile force affected at the test object is placed. The control system provides the remote control of the test and obtaining, processing and presentation of test data. As an example of the testing machine operation the test program and test results of the cyclic tensile fatigue tests of fullscale helium inlet sample of the PF1 coil ITER are presented.

Khitruk, A. A.; Klimchenko, Yu. A.; Kovalchuk, O. A.; Marushin, E. L.; Mednikov, A. A.; Nasluzov, S. N.; Privalova, E. K.; Rodin, I. Yu.; Stepanov, D. B.; Sukhanova, M. V. [The D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), 3 Doroga na Metallostroy, Metallostroy, Saint Petersburg 196641 (Russian Federation)

2014-01-29T23:59:59.000Z

97

April 10, 2014- Workplace Disruptions, Reorganizations, and Change Fatigue: Can ADR Support Resilience?  

Broader source: Energy.gov [DOE]

April 10, 2014 - Workplace Disruptions, Reorganizations, and Change Fatigue: Can ADR Support Resilience?

98

COG fitness for service fatigue program  

SciTech Connect (OSTI)

As the population of nuclear power plants ages, new defects are appearing in Steam Generators (SG) subjected to particularly sever operational stresses, among them pitting, support plate denting, stress corrosion cracking, fatigue induced cracking, and fretting. Utilities are requiring additional data to characterize defects after their detection, i.e., their depth, length and orientation, in order to optimize any tube plugging decision. In this paper, progress report on CANDU development of FFSG (fitness for service) requirements are provided. Currently, the FFSG program has launched projects into three main fields; viz. specimen testing simulating CANDU SG environment especially regarding fatigue crack initiation, propagation and stress corrosion cracking of I-600, I-800 and M-400 alloys, data compilation and evaluations, criteria document preparation for SG tubing degradation evaluations based on deterministic and probabilistic risk assessment methods. The paper as well discusses the database that is currently being prepared for the PVRC. In the PVRC database information is collected from different worldwide sources in Japan Europe, the US and Canada.

Kharshafdjian, G. [AECL, Ontario (Canada)

1996-12-01T23:59:59.000Z

99

J-integral values for cracks in conventional fatigue specimens  

SciTech Connect (OSTI)

Comprehensive S-N fatigue data has been developed worldwide using conventional low-cycle fatigue tests. Such tests use smooth unnotched specimens subjected to controlled axial deflection or strain ranges. The tests must be run in the plastic regime in order to achieve the required cycles-to-failure. Recent developments have highlighted the need to understand and interpret the significance of the resulting strain range vs. cycles to failure data in terms of crack initiation and propagation. Since conventional fatigue tests are conducted in the plastic regime, linear elastic fracture mechanics cannot be used to accurately quantify crack growth in such tests. Elastic-plastic J-integral theory, however, has been shown to provide excellent correlations of crack growth in the elastic, elastic-plastic and grossly-plastic regimes for a wide range of geometric and loading conditions. The authors are applying this theory to the low-cycle fatigue specimen crack behavior. As cracks progress in conventional fatigue specimens, bending becomes significant. Since fatigue testing machines are quite stiff relative to the small fatigue specimens, the ends of the specimen are constrained to remain parallel, and this reduces bending in the cracked cross-section. Three-dimensional finite element elastic-plastic analyses are required to include these constraints in the J-integral solutions.

O`Donnell, T.P.; O`Donnell, W.J. [O`Donnell Consulting Engineers, Pittsburgh, PA (United States)

1996-12-01T23:59:59.000Z

100

The Arithmetic of Elliptic Curves Theory Conjectures  

E-Print Network [OSTI]

The Arithmetic of Elliptic Curves Theory Conjectures Computations Applications Applications John. Fermat's Last Theorem Frey, Ribet: Counterexample to FLT ) 9 non­modular (semi­stable) elliptic curve

Cremona, John

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Reciprocal Relations Between Kinetic Curves  

E-Print Network [OSTI]

We study coupled irreversible processes. For linear or linearized kinetics with microreversibility, $\\dot{x}=Kx$, the kinetic operator $K$ is symmetric in the entropic inner product. This form of Onsager's reciprocal relations implies that the shift in time, $\\exp (Kt)$, is also a symmetric operator. This generates reciprocity relations between kinetic curves. For example, for the Master equation, if we start the process from the $i$th pure state and measure the probability $p_j(t)$ of the $j$th state ($j\

Yablonsky, G S; Constales, D; Galvita, V; Marin, G B

2010-01-01T23:59:59.000Z

102

Multipath Curved Planar Reformation of the Peripheral  

E-Print Network [OSTI]

Multipath Curved Planar Reformation of the Peripheral Arterial Tree in CT Angiography1 Justus that cause artifacts in multipath curved planar reformations (MPCPRs) of the peripheral arterial tree in 10-oblique multiplanar reformations perpendicular to the ves- sel centerline (10), and curved planar reformations

103

Thermomechanics of damage and fatigue by a phase field model  

E-Print Network [OSTI]

In the paper we present an isothermal model for describing damage and fatigue by the use of the Ginzburg-Landau (G-L) equation. Fatigue produces progressive damage, which is related with a variation of the internal structure of the material. The G-L equation studies the evolution of the order parameter, which describes the constitutive arrangement of the system and, in this framework, the evolution of damage. The thermodynamic coherence of the model is proved. In the last part of the work, we extend the results of the paper to a non-isothermal system, where fatigue contains thermal effects, which increase the damage of materials.

Giovambattista Amendola; Mauro Fabrizio

2014-10-26T23:59:59.000Z

104

Micromechanisms of short fatigue crack growth in an Al-Si piston alloy. T.O. Mbuya1  

E-Print Network [OSTI]

1 Micromechanisms of short fatigue crack growth in an Al-Si piston alloy. T.O. Mbuya1 , and P behaviour of a model cast aluminium piston alloy has been investigated. This has been achieved using. Keywords: Fatigue; Short fatigue cracks; Fatigue micromechanics; Al-Si ; Fatigue ; piston alloys 1

105

Center for Inverse Design: Publications  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a bell curve on a graph with many points defined. New selection metric for design of thin-film solar cell absorber materials The Center for Inverse Design has developed...

106

Fatigue behaviour of nanoclay reinforced epoxy resin composites  

Science Journals Connector (OSTI)

Abstract Nanoparticle filling is a feasible way to increase the mechanical properties of polymer matrices. Abundant research work has been published in the last number of years concerning the enhancement of the mechanical properties of nanoparticle filled polymers, but only a reduced number of studies have been done focusing on the fatigue behaviour. This work analyses the influence of nanoclay reinforcement and water presence on the fatigue behaviour of epoxy matrices. The nanoparticles were dispersed into the epoxy resin using a direct mixing method. The dispersion and exfoliation of nanoparticles was characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fatigue strength decreased with the nanoclay incorporation into the matrix. Fatigue life of nanoclay filled composites was significantly reduced by the notch effect and by the immersion in water.

J.A.M. Ferreira; L.P. Borrego; J.D.M. Costa; C. Capela

2013-01-01T23:59:59.000Z

107

Fatigue Enhancement of a Carbon Fiber Reinforced Nanocomposite  

E-Print Network [OSTI]

The primary objective of the present investigation is to study the fatigue characteristics of a woven carbon fiber reinforced polymer which has been modified with either amine or fluorine functionalized carbon nanotubes on the fiber-matrix interface...

Wilkerson, Justin W.

2008-08-19T23:59:59.000Z

108

Fatigue Loads Estimation Through a Simple Stochastic Model  

E-Print Network [OSTI]

We propose a procedure to estimate the fatigue loads on wind turbines, based in a recent framework used for reconstructing data series of stochastic properties measured at wind turbines. Through a standard fatigue analysis, we show that it is possible to accurately estimate fatigue loads in any wind turbine within one wind park, using only the load measurements at one single turbine and the set of wind speed measurements. Our framework consists of deriving a stochastic differential equation that describes the evolution of the torque at one wind turbine driven by the wind speed. The stochastic equation is derived directly from the measurements and is afterwards used for predicting the fatigue loads at neighboring turbines. Such a framework could be used to mitigate the financial efforts usually necessary for placing measurement devices in all wind turbines within one wind farm. Finally, we also discuss the limitations and possible improvements of the proposed procedure.

Lind, Pedro G; Peinke, Joachim

2014-01-01T23:59:59.000Z

109

Fatigue tests of under-strenghth timber railroad bridge stringers  

E-Print Network [OSTI]

OF SCIENCE December 2002 Major Subject: Civil Engineering FATIGUE TESTS OF UNDER-STRENGTH TIMBER RAILROAD BRIDGE STRINGERS A Thesis by CHRISTOPHER RYAN BORCHERS Submitted to Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE Approved as to style and content by: G T. Fry (Chair of Committee) iedz cki of Departme Anne M. Raich (Member) rry L. Kohutek (Member) December 2002 Major Subject: Civil Engineering ABSTRACT Fatigue Tests of Under...

Borchers, Christopher Ryan

2002-01-01T23:59:59.000Z

110

Statistical simulation of small fatigue crack nucleation and coalescence in a lamellar TiAl alloy  

SciTech Connect (OSTI)

This article examines the possibility of fatigue failure as the result of fatigue crack nucleation and coalescence at stress ranges below the fatigue limit and the large crack threshold where fatigue cracks are expected not to grow. By representing the material as a two-dimensional array of beam elements, the nucleation of nonpropagating small cracks at various material locations is modeled via a statistical approach that considers fatigue crack nucleation by accumulation of damage at randomly distributed weak regions. Once nucleated, the fatigue cracks do not propagate but extend only by linking with fatigue cracks subsequently formed in the contiguous elements. Result of the computer simulation suggests that fatigue failure by crack nucleation and coalescence is feasible, but the cycles-to-coalescence is much longer than the cycles-to-initiation for the first crack. Implications of the results in fatigue life assessment based on the Kitagawa diagram are discussed for TiAl alloys.

Chan, K.S. [Southwest Research Inst., San Antonio, TX (United States); Wittowsky, B. [Proctor and Gamble European Service GmbH, Euskirchen (Germany); Pfuff, M. [GKSS Research Center, Geesthacht (Germany)

1999-05-01T23:59:59.000Z

111

Fatigue crack growth testing of sub-clad defects  

SciTech Connect (OSTI)

Fatigue crack growth tests were performed on four-point bend specimens with cracklike defects intentionally placed in A302B low-alloy pressure vessel steel clad with 308/309L weld-deposited stainless steel. The defects were placed in the base metal under the cladding by machining a cavity from the side opposite the cladding, electric-discharge machining a very sharp flaw, fatigue precracking the flaw, and then filling up the cavity by a weld repair process. The specimens were stress relieved before fatigue testing. The specimens were fatigue cycled at positive load ratios until the defects broke through to the surface. The specimens were then fractured at liquid nitrogen temperatures to reveal the fracture surfaces. Seven different sub-clad flaw specimens were tested in room temperature air and each test provides a record of cycles to defect breakthrough. Changes in defect size and shape as a function of applied load cycles were obtained by beach-marking the crack at various stages of the load history. The results provide a set of embedded defect data which can be used for qualifying fatigue crack growth analysis procedures such as those in Section XI of the ASME boiler and Pressure Vessel Code. A comparison between calculated and measured values shows that the ASME B and PV Section XI fatigue crack growth procedures conservatively predict cycles to defect breakthrough for small sub-clad defects.

Jones, D.P.; Leax, T.R. [Bechtel Bettis, Inc., West Mifflin, PA (United States). Bettis Atomic Power Lab.

1999-08-01T23:59:59.000Z

112

UV Light Curves of Thermonuclear Supernovae  

E-Print Network [OSTI]

Ultraviolet light curves are calculated for several thermonuclear supernova models using a multifrequency radiation hydrodynamic code. It is found that Chandrasekhar-mass models produce very similar light curves both for detonation and deflagration. Sub-Chandrasekhar-mass models essentially differ from ``normal'' Chandrasekhar ones regarding behaviour of their UV fluxes. Differences in absolute brightness and in shape of light curves of thermonuclear supernovae could be detectable up to 300 Mpc with modern UV space telescopes.

S. I. Blinnikov; E. I. Sorokina

2000-03-17T23:59:59.000Z

113

PAPILLON: Designing Curved Display Surfaces With Printed Optics  

E-Print Network [OSTI]

. It is based on 3D printed optics, where the surface of the display is constructed as a bundle of printed light Interfaces - Graphical user interfaces; Input devices and strategies. Keywords: 3D printing, fabrication

Poupyrev, Ivan

114

High-resolution spectrometer design using spherically curved crystals  

SciTech Connect (OSTI)

A Bragg crystal spectrometer that has a quartz crystal elastically bent into a segment of a sphere has been successfully constructed and calibrated. The principal advantage of the spherical surface over a cylindrical surface is an increase of almost 3 orders of magnitude in spectral intensity, with no corresponding loss in resolving power. This optical system also possesses good imaging properties. The precision components used in constructing the spectrometer are inexpensive and readily available.

Thoe, R.

1986-09-01T23:59:59.000Z

115

The Arithmetic of Elliptic Curves Theory Conjectures  

E-Print Network [OSTI]

Applications John Cremona University of Exeter #12's Last Theorem Frey, Ribet: Counterexample to FLT ) 9 non-modular (semi-stable) elliptic curve over Q

Cremona, John

116

Canonical correlation of shipping forward curves  

E-Print Network [OSTI]

The behavior and interrelations between the main shipping forward curves are analyzed using multivariate statistics after removing the volatility distortions dictated by the Samuelson hypothesis. Principal Components ...

Hadjiyiannis, Nicholas

2010-01-01T23:59:59.000Z

117

Quantum fields in curved spacetime  

E-Print Network [OSTI]

We review the theory of quantum fields propagating in an arbitrary, classical, globally hyperbolic spacetime. Our review emphasizes the conceptual issues arising in the formulation of the theory and presents known results in a mathematically precise way. Particular attention is paid to the distributional nature of quantum fields, to their local and covariant character, and to microlocal spectrum conditions satisfied by physically reasonable states. We review the Unruh and Hawking effects for free fields, as well as the behavior of free fields in deSitter spacetime and FLRW spacetimes with an exponential phase of expansion. We review how nonlinear observables of a free field, such as the stress-energy tensor, are defined, as well as time-ordered-products. The "renormalization ambiguities" involved in the definition of time-ordered products are fully characterized. Interacting fields are then perturbatively constructed. Our main focus is on the theory of a scalar field, but a brief discussion of gauge fields is included. We conclude with a brief discussion of a possible approach towards a nonperturbative formulation of quantum field theory in curved spacetime and some remarks on the formulation of quantum gravity.

Stefan Hollands; Robert M. Wald

2014-06-10T23:59:59.000Z

118

LIGHT CURVES OF 32 LARGE TRANSNEPTUNIAN OBJECTS  

SciTech Connect (OSTI)

We present observations of 32 primarily bright, newly discovered Transneptunian objects (TNOs) observable from the Southern Hemisphere during 39 nights of observation with the Irenee du Pont 2.5 m telescope at Las Campanas Observatory. Our dataset includes objects in all dynamical classes, but is weighted toward scattered objects. We find 15 objects for which we can fit periods and amplitudes to the data, and place light curve amplitude upper limits on the other 17 objects. Combining our sample with the larger light curve sample in the literature, we find a 3{sigma} correlation between light curve amplitude and absolute magnitude with fainter objects having larger light curve amplitudes. We looked for correlations between light curve and individual orbital properties, but did not find any statistically significant results. However, if we consider light curve properties with respect to object dynamical classification, we find statistically different distributions between the classical-scattered and classical-resonant populations at the 95.60% and 94.64% level, respectively, with the classical objects having larger amplitude light curves. The significance is 97.05% if the scattered and resonant populations are combined. The properties of binary light curves are largely consistent with the greater TNO population except in the case of tidally locked systems. All the Haumea family objects measured so far have light curve amplitudes and rotation periods {<=}10 hr, suggesting that they are not significantly different from the larger TNO population. We expect multiple factors are influencing object rotations: object size dominates light curve properties except in the case of tidal, or proportionally large collisional interactions with other TNOs, the influence of the latter being different for each TNO sub-population. We also present phase curves and colors for some of our objects.

Benecchi, Susan D.; Sheppard, Scott S., E-mail: sbenecchi@dtm.ciw.edu [Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)

2013-05-15T23:59:59.000Z

119

SHM BASED SYSTEM DESIGN OFA WIND TURBINE TOWER USING A MODAL SENSITIVITY BASED BAYES DETECTOR  

E-Print Network [OSTI]

SHM BASED SYSTEM DESIGN OFA WIND TURBINE TOWER USING A MODAL SENSITIVITY BASED BAYES DETECTOR Mads of the NREL 5MW wind turbine tower subjected to bending fatigue and horizontal circumferential cracking

Boyer, Edmond

120

Optimal inspection scheduling with alternative fatigue reliability formulations for steel bridges  

E-Print Network [OSTI]

Optimal inspection scheduling with alternative fatigue reliability formulations for steel bridges H, USA Keywords: steel bridges, structural reliability, fatigue, optimal inspection, fracture, plate girder, box girder ABSTRACT: A reliability-based method for inspection scheduling of steel bridges

Manuel, Lance

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The cognitive performance of patients with multiple sclerosis during periods of high and low fatigue.  

E-Print Network [OSTI]

The objective of this study was to examine whether multiple sclerosis (MS)-related fatigue affects patients' cognitive performance. Thirty patients who had substantial fatigue in conjunction with MS and who reported marked ...

Parmenter, Brett A.; Denney, Douglas R.; Lynch, Sharon G.

2003-03-01T23:59:59.000Z

122

E-Print Network 3.0 - abdominal muscle fatigue Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(2008) doi:10.1016j.gaitpost.2008.03.005 MUSCLE FATIGUE DEGRADES FORCE SENSE AT THE ANKLE JOINT Summary: of muscle fatigue on force sense at the ankle joint, ten young healthy...

123

Effect of whipping stresses on the fatigue damage of ship structures  

Science Journals Connector (OSTI)

Fatigue failures in ships are mainly caused by waves. Higher frequent ... if this approach and the neglect of sequence effects of stress cycles are justified for these ... of the whipping stresses in fatigue anal...

Wolfgang Fricke; Hans Paetzold

2014-03-01T23:59:59.000Z

124

USE OF COMPOSITE MATERIALS TO REPAIR STEEL STRUCTURES VULNERABLE TO FATIGUE DAMAGE  

E-Print Network [OSTI]

This study investigates mainly two different topics related to the use of CFRP's for strengthening and repair of steel bridges: the use of CFRP's to prevent damage in fatigue vulnerable welded connections prior to fatigue-crack initiation...

Alemdar, Fatih

2010-01-01T23:59:59.000Z

125

The effects of asphalt binder oxidation on hot mix asphalt concrete mixture rheology and fatigue performance  

E-Print Network [OSTI]

. The decline in mixture fatigue life (determined using the calibrated mechanistic fatigue analysis approach with surface energy measurement) due to oxidation is significant. Pavement service life is dependent on the mixture, but can be estimated by a cumulative...

Jung, Sung Hoon

2009-06-02T23:59:59.000Z

126

Point-to-curve ray tracing  

Science Journals Connector (OSTI)

Point-to-curve ray tracing is an attempt at dealing with multiplicity of solutions to a generic boundary-value problem of ray tracing. In a point-to-curve tracing (P2C) the input parameters of the boundary-value....

Andrzej Hanyga

1996-01-01T23:59:59.000Z

127

Point-to-curve Ray Tracing  

Science Journals Connector (OSTI)

Point-to-curve ray tracing is an attempt at dealing with multiplicity of solutions to a generic boundary-value problem of ray tracing. In a point-to-curve tracing (P2C) the input parameters of the boundary-value....

Andrzej Hanyga

1996-01-01T23:59:59.000Z

128

E-Print Network 3.0 - amplitude fatigue loading Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Smin Maximum... FATIGUE TESTS AND ... Source: Fatemi, Ali - Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo Collection: Materials...

129

Advanced Tools For Characterizing HMA Fatigue Resistance  

E-Print Network [OSTI]

CHS Mix Aggregate Gradation Blend?????????????...123 17 CHS Mix Adjusted Aggregate Gradation Based on Wet-Sieve Analysis. 124 18 Two Sided t-Test Results for the 20 ?? RDT* Test??????.??. 130? 1 INTRODUCTION Hot mix asphalt concrete... ?? ? (25) where: SFag = Shift factor due to binder oxidative aging u, w = Material regression constants m? = Slope of the binder DSRf (?) master-curve within a reduced frequency range of 1 E-06 to 1 E+02 rad/s at 68?F (20?C) ? = Reduced angular...

Lawrence, James Jefferies

2011-02-22T23:59:59.000Z

130

Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loadings  

SciTech Connect (OSTI)

Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5-MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

2012-01-01T23:59:59.000Z

131

Modeling Thermal Fatigue in CPV Cell Assemblies: Preprint  

SciTech Connect (OSTI)

A finite element model has been created to quantify the thermal fatigue damage of the CPV die attach. Simulations are used to compare to results of empirical thermal fatigue equations originally developed for accelerated chamber cycling. While the empirical equations show promise when extrapolated to the lower temperature cycles characteristic of weather-induced temperature changes in the CPV die attach, it is demonstrated that their damage does not accumulate linearly: the damage a particular cycle contributes depends on the preceding cycles. Simulations of modeled CPV cell temperature histories provided for direct comparison of the FEM and empirical methods, and for calculation of equivalent times provided by standard accelerated test sequences.

Bosco, N.; Silverman, T. J.; Kurtz, S.

2011-07-01T23:59:59.000Z

132

Modeling Creep-Fatigue-Environment Interactions in Steam Turbine Rotor Materials for Advanced Ultra-supercritical Coal Power Plants  

SciTech Connect (OSTI)

The goal of this project is to model creep-fatigue-environment interactions in steam turbine rotor materials for advanced ultra-supercritical (A-USC) coal power Alloy 282 plants, to develop and demonstrate computational algorithms for alloy property predictions, and to determine and model key mechanisms that contribute to the damages caused by creep-fatigue-environment interactions. The nickel based Alloy 282 is selected for this project because it is one of the leading candidate materials for the high temperature/pressure section of an A-USC steam turbine. The methods developed in the project are expected to be applicable to other metal alloys in similar steam/oxidation environments. The major developments are: ? failure mechanism and microstructural characterization ? atomistic and first principles modeling of crack tip oxygen embrittlement ? modeling of gamma prime microstructures and mesoscale microstructure-defect interactions ? microstructure and damage-based creep prediction ? multi-scale crack growth modeling considering oxidation, viscoplasticity and fatigue The technology developed in this project is expected to enable more accurate prediction of long service life of advanced alloys for A-USC power plants, and provide faster and more effective materials design, development, and implementation than current state-of-the-art computational and experimental methods. This document is a final technical report for the project, covering efforts conducted from January 2011 to January 2014.

Shen, Chen

2014-01-20T23:59:59.000Z

133

Reversible Bending Fatigue Test System for Investigating Vibration Integrity of Spent Nuclear Fuel during Transportation  

SciTech Connect (OSTI)

Transportation packages for spent nuclear fuel (SNF) must meet safety requirements under normal and accident conditions as specified by federal regulations. During transportation, SNF experiences unique conditions and challenges to cladding integrity due to the vibrational and impact loading during road or rail shipment. Oak Ridge National Laboratory (ORNL) has been developing testing capabilities that can be used to improve the understanding of the impacts on SNF integrity due to vibration loading, especially for high burn-up SNF in normal transportation operation conditions. This information can be used to meet the nuclear industry and U.S. Nuclear Regulatory Commission needs in the area of safety and security of spent nuclear fuel storage and transport operations. The ORNL developed test system can perform reversible-bending fatigue testing to evaluate both the static and dynamic mechanical response of SNF rods under simulated loads. The testing apparatus is also designed to meet the challenges of hot-cell operation, including remote installation and detachment of the SNF test specimen, in-situ test specimen deformation measurement, and implementation of a driving system suitable for use in a hot cell. The system contains a U-frame set-up equipped with uniquely designed grip rigs, to protect SNF rod and to ensure valid test results, and use of 3 specially designed LVDTs to obtain the in-situ curvature measurement. A variety of surrogate test rods have been used to develop and calibrate the test system as well as in performing a series of systematic cyclic fatigue tests. The surrogate rods include stainless steel (SS) cladding, SS cladding with cast epoxy, and SS cladding with alumina pellets inserts simulating fuel pellets. Testing to date has shown that the interface bonding between the SS cladding and the alumina pellets has a significant impact on the bending response of the test rods as well as their fatigue strength. The failure behaviors observed from tested surrogate rods provides a fundamental understanding of the underlying failure mechanisms of the SNF surrogate rod under vibration which has not been achieved previously. The newly developed device is scheduled to be installed in the hot-cell in summer 2013 to test high burnup SNF.

Wang, Jy-An John [ORNL] [ORNL; Wang, Hong [ORNL] [ORNL; Bevard, Bruce Balkcom [ORNL] [ORNL; Howard, Rob L [ORNL] [ORNL; Flanagan, Michelle [U.S. Nuclear Regulatory Commission] [U.S. Nuclear Regulatory Commission

2013-01-01T23:59:59.000Z

134

AIAA-2001-0025 SPECTRUM FATIGUE LIFETIME AND RESIDUAL STRENGTH  

E-Print Network [OSTI]

fit of the two. Direct lifetime under a variety of loads spectra for wind tests of residual strength for a modified standard wind bone coupons were manufactured, tested and favorably turbine spectrum. When a single and residual strength. Over 900 tests spectrum loading and fatigue lifetimes of a typical wind have been run

135

Dependence of offshore wind turbine fatigue loads on atmospheric stratification  

Science Journals Connector (OSTI)

The stratification of the atmospheric boundary layer (ABL) is classified in terms of the M-O length and subsequently used to determine the relationship between ABL stability and the fatigue loads of a wind turbine located inside an offshore wind farm. Recorded equivalent fatigue loads, representing blade-bending and tower bottom bending, are combined with the operational statistics from the instrumented wind turbine as well as with meteorological statistics defining the inflow conditions. Only a part of all possible inflow conditions are covered through the approximately 8200 hours of combined measurements. The fatigue polar has been determined for an (almost) complete 360 inflow sector for both load sensors, representing mean wind speeds below and above rated wind speed, respectively, with the inflow conditions classified into three different stratification regimes: unstable, neutral and stable conditions. In general, impact of ABL stratification is clearly seen on wake affected inflow cases for both blade and tower fatigue loads. However, the character of this dependence varies significantly with the type of inflow conditions e.g. single wake inflow or multiple wake inflow.

K S Hansen; G C Larsen; S Ott

2014-01-01T23:59:59.000Z

136

Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine: Preprint  

SciTech Connect (OSTI)

Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated 3-D turbulent wind inflow field, with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, while maximizing energy capture. Active damping should be added to these dynamic structures to maintain stability for operation in a complex environment. At the National Renewable Energy Laboratory (NREL), we have designed, implemented, and tested advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on linear models of the turbine that are generated by specialized modeling software. In this paper, we present field test results of an advanced control algorithm to mitigate blade, tower, and drivetrain loads in Region 3.

Wright, A.; Fleming, P.

2010-12-01T23:59:59.000Z

137

2009 Geothermal, Co-Production, and GSHP Supply Curves  

Broader source: Energy.gov (indexed) [DOE]

curves estimate present and future costs of the geothermal resource - Used in market penetration models to predict future electricity landscape * Supply curve input used in...

138

Electrospray characteristic curves: in pursuit of improved performance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electrospray characteristic curves: in pursuit of improved performance in the nano-flow regime. Electrospray characteristic curves: in pursuit of improved performance in the...

139

A review of fatigue crack growth rates for offshore steels in air and seawater environments  

SciTech Connect (OSTI)

A literature review of fatigue crack growth rates (FCGR) has been performed for steels in air and seawater environments, either free corroding or with applied cathodic protection potentials of {minus}850 and {minus}1050/{minus}1100 mV Ag/AgCl. In all cases a more precise description of cracking was obtained using a bi-linear growth law rather than the more conventional Paris Law. Recommendations were made for mean and design values of the constants C and m on a piece-wise basis suitable for use in fracture mechanics analyses of structures. An effect of R-ratio was observed, and separate recommendations were made for high and low R-ratios to cater for as-welded, and post weld heat treated joints with low mean stress levels.

King, R.N. [Failure Control Ltd., Cranleigh (United Kingdom); Stacey, A.; Sharp, J.V. [Health and Safety Executive, London (United Kingdom). Offshore Safety Div.

1996-12-01T23:59:59.000Z

140

MEASUREMENT OF THE SHOCK-HEATED MELT CURVE OF LEAD USING PYROMETRY AND REFLECTOMETRY  

SciTech Connect (OSTI)

Data on the high-pressure melting temperatures of metals is of great interest in several fields of physics including geophysics. Measuring melt curves is difficult but can be performed in static experiments (with laser-heated diamond-anvil cells for instance) or dynamically (i.e., using shock experiments). However, at the present time, both experimental and theoretical results for the melt curve of lead are at too much variance to be considered definitive. As a result, we decided to perform a series of shock experiments designed to provide a measurement of the melt curve of lead up to about 50 GPa in pressure. At the same time, we developed and fielded a new reflectivity diagnostic, using it to make measurements on tin. The results show that the melt curve of lead is somewhat higher than the one previously obtained with static compression and heating techniques.

D. Partouche-Sebban and J. L. Pelissier, Commissariat a` l'Energie Atomique,; F. G. Abeyta, Los Alamos National Laboratory; W. W. Anderson, Los Alamos National Laboratory; M. E. Byers, Los Alamos National Laboratory; D. Dennis-Koller, Los Alamos National Laboratory; J. S. Esparza, Los Alamos National Laboratory; S. D. Borror, Bechtel Nevada; C. A. Kruschwitz, Bechtel Nevada

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives#  

E-Print Network [OSTI]

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives. Aslam and D. S. Stewart TAM Department# University of Illinois Urbana# IL 61801 USA Abstract# Detonation Shock Dynamics #DSD# can be used to model the e#ects that shock curvature # has on detonation speed D n

Aslam, Tariq

142

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives  

E-Print Network [OSTI]

Curved detonation fronts in solid explosives 1 Curved detonation fronts in solid explosives. Aslam and D. S. Stewart TAM Department, University of Illinois Urbana, IL 61801 USA Abstract: Detonation Shock Dynamics (DSD) can be used to model the eects that shock curvature has on detonation speed Dn

Aslam, Tariq

143

Development of fatigue stress spectrum and fatigue life prediction of endless winder sheave for wind turbine lift using finite element analysis  

Science Journals Connector (OSTI)

This paper aims to develop the fatigue stress spectrum and predicted fatigue life of the endless winder sheave using finite element (FE) analysis which is utilized in wind turbine lift. First we identified the fatigue critical location (FCL) of endless winder sheave through a static FE analysis. And the lifting velocity was measured using the non-contact velocity dectector. Based on the measured lifting velocity and compressive loads by traction of endless winder sheave the compressive load-angle of rotation history at the FCL was determined. According to the compressive load-angle of rotation time history total 230 FE analyses were performed with the interval of the angle of rotation of 15 we eventually obtained the fatigue stress spectrum at the FCL. These results were processed using the rainflow cycle counting and the Goodman equation. Finally the fatigue life of sheave was evaluated using the linear damage cumulative rule.

2014-01-01T23:59:59.000Z

144

Hydride-phase formation and its influence on fatigue crack propagationbehavior in a Zircaloy-4 alloy  

SciTech Connect (OSTI)

The hydride-phase formation and its influence on the fatigue behavior of a Zircaloy-4 alloy charged with hydrogen gas are investigated. First, the microstructure and fatigue crack propagation rate of the alloy in the as-received condition are studied. Second, the formation and homogeneous distribution of delta zirconium hydride ( -ZrH2) in the bulk, and its effect on the fatigue crack propagation rate are presented. The results show that in the presence of hydrides the zirconium alloy exhibits reduced toughness and enhanced crack growth rates. Finally, the influence of a pre-existing fatigue crack in the specimen and the subsequent hydride formation were investigated. The residual lattice strain profile around the fatigue crack tip was measured using neutron diffraction. The combined effects of residual strains and hydride precipitation on the fatigue behavior are discussed.

Garlea, Elena [University of Tennessee, Knoxville (UTK); Choo, H. [University of Tennessee, Knoxville (UTK); Wang, G Y [University of Tennessee, Knoxville (UTK); Liaw, Peter K [University of Tennessee, Knoxville (UTK); Clausen, B [Los Alamos National Laboratory (LANL); Brown, D. W. [Los Alamos National Laboratory (LANL); Park, Jae-Sung [University of Tennessee, Knoxville (UTK); Rack, P. D. [University of Tennessee, Knoxville (UTK); Kenik, Edward A [ORNL

2010-01-01T23:59:59.000Z

145

On the Fatigue Reliability of Hydroelectric Francis Runners  

Science Journals Connector (OSTI)

Abstract The reliability assessment of large rotating structures like hydroelectric Francis runners is often limited by our capacity to define a proper limit state combined with a relevant degradation model. In this paper, we propose that the proper limit state for fatigue reliability of such structures is the onset of high cycle fatigue (HCF). Based on this premise, a prior interval for our limit state based on available literature is presented. The prior assumptions are believed to be the first step toward validation of the applicability and suitability of the proposed model. The paper includes an overview of the theoretical background for reliability assessment of Francis turbine runners, the methodology used, and the results obtained from the information gathered from the available literature.

Martin Gagnon; Antoine Tahan; Philippe Bocher; Denis Thibault

2013-01-01T23:59:59.000Z

146

Improve the fatigue life of titanium alloys; Part 1  

SciTech Connect (OSTI)

Heat treatment and mechanical surface treatments of titanium alloys interact in unique ways to allow tailoring of surface microstructures for specific applications. Part 1 of this two-part review discusses the properties of titanium alloys in their various microstructural phases, and Part 2 will describe novel methods for improving fatigue performance by combining mechanical and thermal treatments. Microstructural modification by thermomechanical treatments is widely used to optimize the properties of high-strength titanium alloys for specific applications. However, because the surface of a mechanically loaded titanium part often experiences different conditions than the bulk, it makes sense in many applications to modify only the surface microstructure. By combining thermal treatments with mechanical working, stability of the resulting tailored surface is enhanced. Such stability is especially significant for resistance to fatigue crack nucleation and growth.

Wagner, L. (TU Hamburg-Harburg (Germany)); Gregory, J.K. (GKSS Research Center, Geesthacht (Germany))

1994-03-01T23:59:59.000Z

147

Geodesic Bezier Curves on Triangle Meshes Dimas Martinez Morera  

E-Print Network [OSTI]

Geodesic B´ezier Curves on Triangle Meshes Dimas Mart´inez Morera IMPA - Brazil / ICIMAF - Cuba generalization of B´ezier curves. Thus, we call them "Geodesic B´ezier Curves". Geodesic B´ezier curves, but geodesics connecting the control points. This imposes the necessity of modifying the inter- polation step

148

Complex Fluid Analysis with the Advanced Distillation Curve Approach  

E-Print Network [OSTI]

Complex Fluid Analysis with the Advanced Distillation Curve Approach Thomas J. Bruno, Lisa S. Ott for measuring distillation curves reveals the physicochemical properties of complex fluids such as fuels distillation curves of complex fluids. The distillation curve provides the only practical avenue to assess

149

Differential and Numerically Invariant Signature Curves Applied to Object Recognition  

Science Journals Connector (OSTI)

We introduce a new paradigm, the differential invariant signature curve or manifold, for the invariant recognition of visual objects. A general theorem of . Cartan implies that two curves are related by a group transformation if and only if ... Keywords: Euclidean group, curve shortening flow, differential invariant, equi-affine group, joint invariant, numerical approximation, object recognition, signature curve, snake, symmetry group

Eugenio Calabi; Peter J. Olver; Chehrzad Shakiban; Allen Tannenbaum; Steven Haker

1998-02-01T23:59:59.000Z

150

SOLVING CURVED DETONATION RIEMANN PROBLEMS Bruce Bukiet  

E-Print Network [OSTI]

SOLVING CURVED DETONATION RIEMANN PROBLEMS Bruce Bukiet Department of Mathematics, Center to compute accurate solutions to detonation problems without numerically solving differential equations in the thin reaction zone. For planar detonation waves, alge­ braic jump conditions can be used to compute

Bukiet, Bruce

151

Tracing compressed curves in triangulated surfaces  

Science Journals Connector (OSTI)

A simple path or cycle in a triangulated surface is normal if it intersects any triangle in a finite set of arcs, each crossing from one edge of the triangle to another. We describe an algorithm to "trace" a normal curve in O(min set{X, n2log ... Keywords: computational topology, geodesics, normal coordinates

Jeff Erickson; Amir Nayyeri

2012-06-01T23:59:59.000Z

152

E-Print Network 3.0 - assisted fatigue crack Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Grain-Boundary Adhesion Summary: unless they experience environmentally assisted subcritical growth during cyclic loading.7 Fatigue-crack... (moist air and dry N2). The...

153

Self-management associated with fatigue in patients with advanced cancer : a prospective longitudinal study.  

E-Print Network [OSTI]

??Cancer-related fatigue is one of the most distressing symptoms experienced by patients with advanced cancer. This doctoral study identified that patients with advanced cancer commonly (more)

Chan, Raymond

2014-01-01T23:59:59.000Z

154

High temperature erosion and fatigue resistance of a detonation gun chromium carbide coating for steam turbines  

SciTech Connect (OSTI)

Chromium carbide based detonation gun coatings have been shown to be capable of protecting steam turbine components from particle erosion. To be usable, however, erosion resistant coatings must not degrade the fatigue characteristics of the coated components. Recent studies of the fatigue properties of a detonation gun coated martensitic substrate at 538 C (1,000 F) will be presented with an emphasis on its long term performance. This study will show the retention of acceptable fatigue performance of coated substrates into the high cycle regime, and will include a discussion on the mechanism of fatigue.

Quets, J.M.; Walsh, P.N. [Praxair Surface Technologies, Inc., Indianapolis, IN (United States); Srinivasan, V. [Westinghouse Electric Corp., Orlando, FL (United States); Tucker, R.C. Jr. [Praxair Surface Technologies, Inc., Indianapolis, IN (United States)

1994-12-31T23:59:59.000Z

155

Properties and mechanism on flexural fatigue of polypropylene fiber reinforced concrete containing slag  

Science Journals Connector (OSTI)

Properties and mechanism were investigated on flexural fatigue of concrete containing polypropylene fibers and ground granulated blast furnace slag(GGBFS). Four polypropylene fibers volume fractions and five ...

Huili Zhang ???; Kanliang Tian

2011-06-01T23:59:59.000Z

156

Tensile fatigue behavior of tapered glass fiber reinforced epoxy composites containing nanoclay  

Science Journals Connector (OSTI)

Abstract Tensile fatigue behavior of tapered glass/epoxy laminates is investigated. The effect of nanoclay addition into the epoxy resin is examined. It is shown that the relative orientation between the adjacent belt layer and the cut layer has important influence on the fatigue life. The fatigue crack starts at the resin pocket and propagates along the interface between the belt layer and the core layer in the thicker section of the laminate. Crack propagation is mainly due to mode II crack failure. The addition of the clays enhances the resistance against this mode II crack propagation, and thus prolongs the fatigue life of the laminate.

S. Helmy; S.V. Hoa

2014-01-01T23:59:59.000Z

157

E-Print Network 3.0 - anomolous fatigue crack Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Science ; Engineering 6 Cracking Resistance of Asphalt Rubber Mix Versus Summary: vs. Fracture Mechanics Conventional Fatigue Testing Crack initiation Fracture Mechanics Crack......

158

Beauty waves: an artistic representation of ocean waves using Bezier curves  

E-Print Network [OSTI]

In this thesis, we present a method for computing an artistic representation of ocean waves using Bezier curves. Wave forms are loosely based on procedural wave models and are designed to emulate those found in both art and nature. The wave forms...

Faulkner, Jay Allen

2007-04-25T23:59:59.000Z

159

An Energy Based Fatigue Lifing Method for In-Service Components and Numerical Assessment of U10Mo Alloy Based Fuel Mini Plates.  

E-Print Network [OSTI]

??An energy based fatigue life prediction framework has been developed for calculation of remaining fatigue life of in service gas turbine materials. The purpose of (more)

Ozaltun, Hakan

2011-01-01T23:59:59.000Z

160

New reversing design method for LED uniform illumination  

Science Journals Connector (OSTI)

In light-emitting diode (LED) applications, it is becoming a big issue that how to optimize light intensity distribution curve (LIDC) and design corresponding optical component to...

Wang, Kai; Wu, Dan; Qin, Zong; Chen, Fei; Luo, Xiaobing; Liu, Sheng

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Curved butterfly bileaflet prosthetic cardiac valve  

DOE Patents [OSTI]

An annular valve body having a central passageway for the flow of blood therethrough with two curved leaflets each of which is pivotally supported on an accentric positioned axis in the central passageway for moving between a closed position and an open position. The leaflets are curved in a plane normal to the eccentric axis and positioned with the convex side of the leaflets facing each other when the leaflets are in the open position. Various parameters such as the curvature of the leaflets, the location of the eccentric axis, and the maximum opening angle of the leaflets are optimized according to the following performance criteria: maximize the minimum peak velocity through the valve, maximize the net stroke volume, and minimize the mean forward pressure difference, thereby reducing thrombosis and improving the hemodynamic performance.

McQueen, David M. (185 Hillside Ave., Chatham, NJ 07928); Peskin, Charles S. (186 Harrard Dr., Hartsdale, NY 10530)

1991-06-25T23:59:59.000Z

162

Light Curves of Swift Gamma Ray Bursts  

E-Print Network [OSTI]

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars.

Paolo Cea

2006-09-22T23:59:59.000Z

163

Galaxy rotation curves in de Sitter space  

E-Print Network [OSTI]

Dark energy inferred from the observed negative deceleration parameter introduces a small mass of the graviton, that satisfies the Higuchi stability condition. It implies an infra-red modification of gravitation that produces Milgrom's inverse distance law of gravitational attraction in excellent agreement with the observed galaxy rotation curves. We conclude that dark matter is present cosmologically with no need for local clustering in galaxies.

Maurice H. P. M. van Putten

2015-01-27T23:59:59.000Z

164

OPTICAL PHASE CURVES OF KEPLER EXOPLANETS  

SciTech Connect (OSTI)

We conducted a comprehensive search for optical phase variations of all close-in (a/R{sub *} < 10) planet candidates in 15 quarters of Kepler space telescope data. After correcting for systematics, we found eight systems that show secondary eclipses as well as phase variations. Of these, five (Kepler-5, Kepler-6, Kepler-8, KOI-64, and KOI-2133) are new and three (TrES-2, HAT-P-7, and KOI-13) have published phase curves, albeit with many fewer observations. We model the full phase curve of each planet candidate, including the primary and secondary transits, and derive their albedos, dayside and nightside temperatures, ellipsoidal variations, and Doppler beaming. We find that KOI-64 and KOI-2133 have nightside temperatures well above their equilibrium values (while KOI-2133 also has an albedo, >1), so we conclude that they are likely to be self-luminous objects rather than planets. The other six candidates have characteristics consistent with their being planets with low geometric albedos (<0.3). For TrES-2 and KOI-13, the Kepler bandpass appears to probe atmospheric layers hotter than the planet's equilibrium temperature. For KOI-13, we detect a never-before-seen third cosine harmonic with an amplitude of 6.7 {+-} 0.3 ppm and a phase shift of -1.1 {+-} 0.1 rad in the phase curve residual, possibly due to its spin-orbit misalignment. We report derived planetary parameters for all six planets, including masses from ellipsoidal variations and Doppler beaming, and compare our results to published values when available. Our results nearly double the number of Kepler exoplanets with measured phase curve variations, thus providing valuable constraints on the properties of hot Jupiters.

Esteves, Lisa J.; De Mooij, Ernst J. W.; Jayawardhana, Ray, E-mail: esteves@astro.utoronto.ca, E-mail: demooij@astro.utoronto.ca, E-mail: rayjay@astro.utoronto.ca [Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4 (Canada)

2013-07-20T23:59:59.000Z

165

Particle transport in turbulent curved pipe flow  

E-Print Network [OSTI]

Direct numerical simulations (DNS) of particle-laden turbulent flow in straight, mildly curved and strongly bent pipes are performed in which the solid phase is modelled as small heavy spherical particles. The objective is to examine the effect of the curvature on particle transport and accumulation, in particular how the turbophoretic drift of the particles is affected by weak and strong secondary motions of the carrier phase and geometry-induced centrifugal forces. A total of seven populations of dilute particles with different Stokes numbers, one-way coupled with their carrier phase, are simulated. Even a slight non-zero curvature in the flow configuration shows a strong impact on the particle dynamics. Near-wall helicoidal particle streaks are observed in the curved configurations with their inclination varying with the strength of the secondary motion of the carrier phase. A reflection layer, as previously observed in particle laden turbulent S-shaped channels, is also apparent in the strongly curved pip...

Noorani, Azad; Brandt, Luca; Schlatter, Philipp

2015-01-01T23:59:59.000Z

166

The fatigue of high-strength fused silica optical fibers in low humidity q  

E-Print Network [OSTI]

the effect of humidity on the kinetics of subcritical crack growth in high strength optical fibers that the rate of subcritical crack growth is given by dc dt ¼ A exp n KI KIC ; ð1? where A and n are fatigue by assuming a simple chemical kinetics model for fatigue in which the reaction rate between water and silica

Matthewson, M. John

167

Mitigation of Fatigue Loads Using Individual Pitch Control of Wind Turbines Based on FAST  

E-Print Network [OSTI]

Mitigation of Fatigue Loads Using Individual Pitch Control of Wind Turbines Based on FAST Yunqian University, China jiz@seu.edu.cn Abstract-With the increase of wind turbine dimension and capacity, the wind turbine structures are subjected to prominent loads and fatigue which would reduce the lifetime of wind

Chen, Zhe

168

THERMAL FATIGUE AND FAILURE OF ELECTRONIC POWER DEVICE SUBSTRATES. S. Pietranico1&2  

E-Print Network [OSTI]

. For large thermal amplitudes, the failure occurs in DBC substrates, which are copper/ceramic- 1 - THERMAL FATIGUE AND FAILURE OF ELECTRONIC POWER DEVICE SUBSTRATES. S. Pietranico1&2 , S their thermal fatigue and failure. For example, for power modules mounted on the engine of an aircraft

Paris-Sud XI, Université de

169

The SNL/MSU/DOE Fatigue of Composite Materials Database: Recent Trends  

E-Print Network [OSTI]

1 The SNL/MSU/DOE Fatigue of Composite Materials Database: Recent Trends Daniel D. Samborsky1 in three areas are described for wind blade materials in the SNL/MSU/DOE fatigue of composite materials failure, epoxy based blade adhesives and core materials. Comparisons of fiber dominated and resin

170

Estimation of Muscle Fatigue during Cyclic Contractions Using Source Separation Techniques  

Science Journals Connector (OSTI)

Previous research studies have reported that spectral compression of the surface Electromyogram (SEMG) towards lower frequencies is associated with onset of localized muscle fatigue. One reason for this spectral compression has been attributed to motor ... Keywords: ICA, Muscle fatigue, Source separation, Surface EMG

Ganesh R. Naik; Dinesh K. Kumar; Katherine Wheeler; Sridhar P. Arjunan

2009-12-01T23:59:59.000Z

171

Delamination at Thick Ply Drops in Carbon and Glass Fiber Laminates Under Fatigue Loading  

E-Print Network [OSTI]

1 Delamination at Thick Ply Drops in Carbon and Glass Fiber Laminates Under Fatigue Loading Daniel in composites with thickness tapering has been a concern in applications of carbon fibers. This study explored the resistance to delamination under fatigue loading of carbon and glass fiber prepreg laminates with the same

172

Probabilistic fatigue life prediction model for alloys with defects: applied to A206  

SciTech Connect (OSTI)

Presented here is a model for the prediction of fatigue life based on the statistical distribution of pores, intermetallic particles and grains. This has been applied to a cast Al alloy A206, before and after friction stir processing (FSP). The model computes the probability to initiate a small crack based on the probability of finding combinations of defects and grains on the surface. The crack initiation and propagation life of small cracks due to these defect and grain combinations are computed and summed to obtain the total fatigue life. The defect and grain combinations are ranked according to total fatigue life and the failure probability computed. Bending fatigue experiments were carried out on A206 before and after FSP. FSP eliminated the porosity, broke down the particles and refined the microstructure. The model predicted the fatigue life of A206 before and after FSP well. The cumulative probability distribution vs. fatigue life was fitted to a three parameter Weibull distribution function. The scatter reduced after FSP and the threshold of fatigue life increased. The potential improvement in the fatigue life of A206 for a microstructure consisting of a finer distribution of particle sizes after FSP was predicted using the model.

Kapoor, Rajeev; Sree Hari Rao, V.; Mishra, Rajiv S.; Baumann, John A.; Grant, Glenn J.

2011-05-31T23:59:59.000Z

173

CONTINUOUS FATIGUE ASSESSMENT OF AN OFFSHORE WIND TURBINE USING A LIMITED NUMBER OF VIBRATION SENSORS  

E-Print Network [OSTI]

CONTINUOUS FATIGUE ASSESSMENT OF AN OFFSHORE WIND TURBINE USING A LIMITED NUMBER OF VIBRATION, Modal decomposition and expansion, Finite Element Model INTRODUCTION Offshore wind turbines are exposed locations along the structure. This is not the case though in monopile offshore wind turbines, where fatigue

Boyer, Edmond

174

A unified method for the analysis of nonlinear viscoelasticity and fatigue cracking of asphalt mixtures using the dynamic mechanical analyzer  

E-Print Network [OSTI]

..................................................................................... 69 Energy Method to Characterize Fatigue Damage in Asphalt Pavements .................................................................................... 70 Definition of Dissipated Energy (DE) Components.... Dallas N. Little Fatigue cracking is one of the primary modes of distress in asphalt pavements that has an important economic impact. Fatigue resistance characterization of an asphalt mixture is a complex issue due to: (i) composite nature...

Castelo Branco, Veronica Teixeira Franco

2009-05-15T23:59:59.000Z

175

Towards a renaissance of curved spanning structures  

E-Print Network [OSTI]

Today, as always, there is a great need for expressiveness in design. There are a multitude of forms which, over the years, have been stripped from the designer's repertoire in the name of economics. There exists a sub-group ...

Hartshorne, Thomas Hunter

1983-01-01T23:59:59.000Z

176

A new muscle fatigue and recovery model and its ergonomics application in human simulation  

E-Print Network [OSTI]

Although automatic techniques have been employed in manufacturing industries to increase productivity and efficiency, there are still lots of manual handling jobs, especially for assembly and maintenance jobs. In these jobs, musculoskeletal disorders (MSDs) are one of the major health problems due to overload and cumulative physical fatigue. With combination of conventional posture analysis techniques, digital human modelling and simulation (DHM) techniques have been developed and commercialized to evaluate the potential physical exposures. However, those ergonomics analysis tools are mainly based on posture analysis techniques, and until now there is still no fatigue index available in the commercial software to evaluate the physical fatigue easily and quickly. In this paper, a new muscle fatigue and recovery model is proposed and extended to evaluate joint fatigue level in manual handling jobs. A special application case is described and analyzed by digital human simulation technique.

Ma, Liang; Bennis, Fouad; Zhang, Wei; Guillaume, Franois; 10.1080/17452759.2010.504056

2010-01-01T23:59:59.000Z

177

A new muscle fatigue and recovery model and its ergonomics application in human simulation  

E-Print Network [OSTI]

Although automatic techniques have been employed in manufacturing industries to increase productivity and efficiency, there are still lots of manual handling jobs, especially for assembly and maintenance jobs. In these jobs, musculoskeletal disorders (MSDs) are one of the major health problems due to overload and cumulative physical fatigue. With combination of conventional posture analysis techniques, digital human modelling and simulation (DHM) techniques have been developed and commercialized to evaluate the potential physical exposures. However, those ergonomics analysis tools are mainly based on posture analysis techniques, and until now there is still no fatigue index available in the commercial software to evaluate the physical fatigue easily and quickly. In this paper, a new muscle fatigue and recovery model is proposed and extended to evaluate joint fatigue level in manual handling jobs. A special application case is described and analyzed by digital human simulation technique.

Ma, Liang; Bennis, Fouad; Zhang, Wei; Guillaume, Franois

2009-01-01T23:59:59.000Z

178

Quantifying fatigue generated in high strain rate cyclic loading of Norway spruce  

Science Journals Connector (OSTI)

Papermaking especially mechanical pulping consumes much energy. To reduce this energy consumption one has to understand and exploit the phenomena present during the pulping. An important phenomenon to understand is wood fatigue. We quantitatively measure the fatigue generated during high strain rate cyclic loading of spruce wood performed under conditions resembling those present during mechanical pulping. We impacted the samples with 5% strain pulses at 500 Hz. The radial direction stiffness drop in the samples was quantified by 500 kHz ultrasonic through-transmission postimpacting. The depth profile of the generated fatigue was also determined. A dependency of the amount of fatigue generated during cyclic straining on the moisture content was detected. A hypothesis about the temporal and spatial evolution of the fatigue during the process is presented. The results supporting the hypothesis provide insight into wood behavior under mechanical pulping conditions.

Ari Salmi; Lauri Salminen; Edward Hggstrm

2009-01-01T23:59:59.000Z

179

Safety evaluation of limited sight distance at crest vertical curves on two-lane rural roadways in Texas  

E-Print Network [OSTI]

. Study Objectives Scope . Organization of the Thesis 1 4 . . 4 5 2. LITERATURE REVIEW Current SSD Model Stopping SSD Design Parameters Sensitivity of Parameters Safety and SSD Relevance of Past Research to This Thesis 6 6 9 . 17 20... Sections for AADT Volumes from 5, 000 to 9, 900 and Grades Above and Below 3 Percent . . 4. Influence of Curves on Gradients on Accident Rates for German Expressways 5. Freeway Accidents Rates for Diffeent Types of Crest and Sag Vertical Curves 6...

George, Karen Maria

2012-06-07T23:59:59.000Z

180

Degradation of nanostructured bainitic steel under rolling contact fatigue  

E-Print Network [OSTI]

treatment and af- ter the longest running RCF test were determined using a Philips PW1830 vertical di?ractometer with a CuK? radiation. Scans were performed from 30 to 125 #0;, with a step size of 0.05 #0; and a dwell time of 26 s. A divergence slit of 0... torsion with compressive mean stress: in: Mechanics of Materials: Japan Society of Mechanical Engi- neers, Tokyo, Japan, 2000: pp. 241243. [18] K. Burkart, H. Bomas, R. Schroeder, H.-W. Zoch: Rolling contact and compression-torsion fatigue of 52100 steel...

Solano-Alvarez, W.; Pickering, E. J.; Bhadeshia, H. K. D. H.

2014-09-06T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Stress intensity factors for small fatigue cracks in tubular joints  

SciTech Connect (OSTI)

Some simple fracture mechanics models are presented for estimating stress intensity factors for small surface fatigue cracks in welded tubular joints. Model predictions are compared with large-scale experimental results for the cases of in-plane and out-of-plane bending in multi-brace tubular nodes. It is demonstrated that reasonably accurate predictions of the stress intensity factor are possible using a modified flat plate solution if the effects of weld geometry, load shedding and crack shape are adequately accounted for.

Monahan, C.C. [Memorial Univ. of Newfoundland, St. Johns, Newfoundland (Canada). Centre for Cold Ocean Resources Engineering; Dover, W.D. [University College, London (United Kingdom)

1995-12-31T23:59:59.000Z

182

Existence and stability of curved multidimensional detonation fronts  

E-Print Network [OSTI]

Existence and stability of curved multidimensional detonation fronts N. Costanzino , H. K. Jenssen of curved detonation fronts 32 7.1 ZND fronts of strong detonations in the two most commonly studied inviscid models of combustion, the ZND (finite

183

Microplasticity and fatigue of some magnesium-lithium alloys  

Science Journals Connector (OSTI)

Cyclic stress-strain curves have been obtained for a series of magnesium-lithium alloys with lithium contents up to 12. 5wt%. The ... hardening exponents for stresses leading to failure in excess of 104...cycles ...

R. E. Lee; W. J. D. Jones

1974-03-01T23:59:59.000Z

184

Calibrating Curved Crystals Used for Plasma Spectroscopy  

SciTech Connect (OSTI)

The throughput and resolving power of an X-ray spectrometer that uses a curved crystal as the diffraction element is determined primarily by the crystal X-ray reflectivity properties. This poster presents a measurement technique for these crystal parameters using a simple diode source to produce a narrow spectral band. The results from measurements on concave elliptical polyethylene terephthalate (PET) crystals and convex potassium acid phthalate (KAP) crystals show large variations in the key parameters compared to those from the flat crystal.

Haugh, M. J., Jacoby, K. D., Ross, P. W., Rochau, G. Wu, M., Regan, S. P., Barrios, M. A.

2012-10-29T23:59:59.000Z

185

Geodesic conic subdivision curves on surfaces J. Estrada Sarlabous  

E-Print Network [OSTI]

Geodesic conic subdivision curves on surfaces J. Estrada Sarlabous V. Hern´andez Mederos N. L Matem´atica UFAL Maceio, Brazil Email: dimas@mat.ufal.br Fig. 1. Geodesic conic subdivision curves is inspired in the concept of geodesic B´ezier curves. Starting with a geodesic control polygon with vertices

186

HOW MUCH INFLUENCE DOES CONSTRUCTION HAVE ON CURVED STEEL  

E-Print Network [OSTI]

HOW MUCH INFLUENCE DOES CONSTRUCTION HAVE ON CURVED STEEL BRIDGES? RESULTS FROM EXPERIMENTAL UNIVERSITY IBC-00-58 Keywords: curved, steel, girder, bridge, construction, erection, fabrication, testing and analytical research program to study curved steel bridge behavior. The program centered on testing a series

187

COMPUTER GENERATION OF TYPE CURVES SUBMITIED TO THE DEPARTMENTOF PETROLEUMENGINEERING  

E-Print Network [OSTI]

COMPUTER GENERATION OF TYPE CURVES A REPORT SUBMITIED TO THE DEPARTMENTOF PETROLEUMENGINEERING data. This paper presents some previously published type curves and the computer programs that were between two parallel sealing faults. The governing equations for these curves are derived. The computer

Stanford University

188

Conservation Screening Curves to Compare Efficiency Investments to Power Plants  

E-Print Network [OSTI]

curve approach supplements with load shape information the data contained in a supply curve of conservedLBL-27286 Conservation Screening Curves to Compare Efficiency Investments to Power Plants Jonathan to Compare Efficiency Investments to Power Plants Jonathan Koomey, Arthur H. Rosenfeld, and Ashok Gadgil

189

Patterns and coincidences in the light curves of active galaxies  

Science Journals Connector (OSTI)

......Patterns and coincidences in the light curves of active galaxies Roberto...coincident patterns in the optical light curves of NGC 4151 and 5548...are due to a Poissonian (,Christmas-tree') type of process...Patterns in the light curves ofactive galaxies 325......

Roberto Cid Fernandes; Jr; Roberto Terlevich; Itziar Aretxaga

1997-08-01T23:59:59.000Z

190

The Severi problem for rational curves on del Pezzo surfaces  

E-Print Network [OSTI]

Let X be a smooth projective surface and choose a curve C on X. Let VC be the set of all irreducible divisors on X linearly equivalent to C whose normalization is a rational curve. The Severi problem for rational curves ...

Testa, Damiano

2005-01-01T23:59:59.000Z

191

Parameterization and Applications of Catmull-Rom Curves  

E-Print Network [OSTI]

Parameterization and Applications of Catmull-Rom Curves Cem Yuksel, Scott Schaefer, John Keyser 3112 Texas A&M University College Station, TX 77843-3112 Abstract The behavior of Catmull-Rom curves ambiguous. In this paper we prove that, for cubic Catmull-Rom curves, centripetal parameterization

Keyser, John

192

Oil production models with normal rate curves Dudley Stark  

E-Print Network [OSTI]

Oil production models with normal rate curves Dudley Stark School of Mathematical Sciences Queen;Abstract The normal curve has been used to fit the rate of both world and U.S.A. oil production. In this paper we give the first theoretical basis for these curve fittings. It is well known that oil field

Stark, Dudley

193

Passive solar design handbook  

SciTech Connect (OSTI)

The Passive Solar Design Handbook, Volume Three updates Volume Two by presenting extensive new data on the optimum mix of conservation and solar direct gain, sunspaces, thermal storage walls, and solar radiation. The direct gain, thermal storage wall, and solar radiation data are greatly expanded relative to the Volume 2 coverage. The needed flexibility to analyze a variety of system designs is accommodated by the large number of reference designs to be encompassed - 94 in contrast to 6 in Volume two - and the large amount of sensitivity data for direct gain and sunspace systems - approximately 1100 separate curves.

Jones, R.W.

1981-01-01T23:59:59.000Z

194

Fatigue and environmentally assisted cracking in light water reactors  

SciTech Connect (OSTI)

Fatigue and stress corrosion cracking (SCC) for low-alloy steel used in piping and in steam generator and reactor pressure vessels have been investigated. Fatigue data were obtained on medium-sulfur-content A533-Gr B and A106-Gr B steels in high-purity (HP) deoxygenated water, in simulated pressurized water reactor water, and in air. Analytical studies focused on the behavior of carbon steels in boiling water reactor (BWR) environments. Crack-growth rates of composite fracture-mechanics specimens of A533-Gr B/Inconel-182/Inconel-600 (plated with nickel) and homogeneous specimens of A533-Gr B steel were determined under small-amplitude cyclic loading in HP water with {approx}300 pbb dissolved oxygen. Radiation-induced segregation and irradiation-assisted SCC of Type 304 SS after accumulation of relatively high fluence also have been investigated. Microchemical and microstructural changes in HP and commercial-purity Type 304 SS specimens from control-blade absorber tubes used in two operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy, and slow-strain-rate tensile tests were conducted on tubular specimens in air and in simulated BWR water at 289{degrees}C.

Kassner, T.F.; Ruther, W.E.; Chung, H.M.; Hicks, P.D.; Hins, A.G.; Park, J.Y.; Shack, W.J.

1992-03-01T23:59:59.000Z

195

Low cycle fatigue behavior of Zircaloy-2 at room temperature  

Science Journals Connector (OSTI)

Abstract Fuel cladding and pressure tubes of Zircaloy-2 in pressurized light and heavy water nuclear reactors experience plastic strain cycles due to power fluctuations in the reactor, such strain cycles cause low cycle fatigue (LCF) and could be life limiting factor for them. Factors like strain rate, strain amplitude and temperature are known to have marked influence on LCF behavior. The effect of strain rate from 10?2 to 10?4s?1 on LCF behavior of Zircaloy-2 was studied, at different strain amplitudes between 0.50% and 1.25% at room temperature. Fatigue life was decreased with lowering of strain rate from 10?2 to 10?4s?1 at all the strain amplitudes studied. While there was cyclic softening at lower strain amplitudes (??t/2?0.60%) cyclic hardening was exhibited at higher strain amplitudes (??t/2?1.00%) at all the strain rates. Further, there was secondary cyclic hardening during the later stage of cycling at all the strain amplitudes and the strain rates. Cyclic stressstrain hysteresis loops at the lowest strain rate of 10?4s?1 were found to be heavily serrated, resulting from dynamic strain aging (DSA). There was significant effect of strain rate on dislocation substructure. The results are discussed in terms of high concentration of point defects generated during cyclic straining and their role in enhancing interaction between solutes and dislocations.

G. Sudhakar Rao; J.K. Chakravartty; Saibaba Nudurupati; G.S. Mahobia; Kausik Chattopadhyay; N.C. Santhi Srinivas; Vakil Singh

2013-01-01T23:59:59.000Z

196

Human performance modeling for system of systems analytics :soldier fatigue.  

SciTech Connect (OSTI)

The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

2005-10-01T23:59:59.000Z

197

Multiaxial low-cycle fatigue damage evaluation using a. c. potential method for alloy 738LC superalloy  

SciTech Connect (OSTI)

This paper studies tension/torsion multiaxial low-cycle fatigue lives and creep-fatigue damage evaluation for Alloy 738LC superalloy. Tension/torsion creep-fatigue tests were carried out using hollow cylinder specimens and multiaxial creep-fatigue lives were obtained. The Mises' equivalent strain correlated the multiaxial low cycle fatigue lives within a factor of two scatter band. An a.c. potential method is developed to detect the creep-fatigue damage associated with crack nucleation and extension. A.c. potentials at high frequencies accurately detect the creep-fatigue damage from the early stage of life while those at low frequencies detect that in the final stage of life. A.c. potentials at high frequencies detect the crack density, defined as the total crack length per unit area, and maximum crack length more sensitivity than those at low frequencies.

Isono, Yoshitada; Sakane, Masao; Ohnami, Masateru (Ritsumeikan Univ., Kyoto (Japan). Dept. of Mechanical Engineering); Fujiyama, Kazunari (Toshiba Corp., Yokohama (Japan). Heavy Apparatus Engineering Lab.)

1994-10-01T23:59:59.000Z

198

Selected GHG Emission Supply Curves | Open Energy Information  

Open Energy Info (EERE)

Selected GHG Emission Supply Curves Selected GHG Emission Supply Curves Jump to: navigation, search Tool Summary Name: Selected GHG Emission Supply Curves Agency/Company /Organization: Northwest Power and Conservation Council Sector: Energy Focus Area: Conventional Energy, Energy Efficiency, Renewable Energy, Industry, Transportation, Forestry, Agriculture Topics: GHG inventory, Pathways analysis Resource Type: Dataset, Publications Website: www.nwcouncil.org/energy/grac/20090130_Supply%20Curves_NWPCC_FINAL.pdf Selected GHG Emission Supply Curves Screenshot References: Selected GHG Emission Supply Curves[1] Background "The ECL supply curve model includes data on potential emission reductions for approximately 60 separate technology options. It allows the examination of multiple scenarios involving the inclusion or exclusion of technology

199

Curved Spacetimes and Curved Graphene: a status report of the Weyl-symmetry approach  

E-Print Network [OSTI]

This is a status report about the ongoing work on the realization of quantum field theory on curved graphene spacetimes that uses Weyl symmetry. The programme is actively pursued from many different perspectives. Here we point to what has been done, and to what needs to be done.

Iorio, Alfredo

2014-01-01T23:59:59.000Z

200

Curved Spacetimes and Curved Graphene: a status report of the Weyl-symmetry approach  

E-Print Network [OSTI]

This is a status report about the ongoing work on the realization of quantum field theory on curved graphene spacetimes that uses Weyl symmetry. The programme is actively pursued from many different perspectives. Here we point to what has been done, and to what needs to be done.

Alfredo Iorio

2014-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Low cycle fatigue crack initiation life assessment of HY-100 undermatched weld  

SciTech Connect (OSTI)

An evaluation is conducted of several approaches to the prediction of low cycle fatigue crack initiation in HY-100 welds of an undermatched weldment. FEM analyses and experiments using various types of low cycle fatigue specimens were conducted and their results were compared with the results of such theoretical algorithms as Neuber's rule. A two-surface cyclic plasticity algorithm was implanted in a FEM code's user subroutine in order to simulate the material's cyclic stress-strain behavior under cyclic loading conditions; fatigue tests ranging from small, standard smooth specimens to notched cylindrical specimens with notch constraint were conducted for HY-100. 11 refs.

Wang, K.; Shah, R.; Yuan, D.; Kleinosky, M.J.

1993-01-01T23:59:59.000Z

202

Updated U.S. Geothermal Supply Curve  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

CP-6A2-47458 CP-6A2-47458 February 2010 Updated U.S. Geothermal Supply Curve Chad Augustine and Katherine R. Young National Renewable Energy Laboratory Arlene Anderson U.S. Department of Energy Presented at Stanford Geothermal Workshop Stanford, California February 1, 2010 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (ASE), a contractor of the US Government under Contract No. DE-AC36-08-GO28308. Accordingly, the US Government and ASE retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

203

Quantum fields on closed timelike curves  

SciTech Connect (OSTI)

Recently, there has been much interest in the evolution of quantum particles on closed timelike curves (CTCs). However, such models typically assume pointlike particles with only two degrees of freedom; a very questionable assumption given the relativistic setting of the problem. We show that it is possible to generalize the Deutsch model of CTCs to fields using the equivalent circuit formalism. We give examples for coherent, squeezed, and single-photon states interacting with the CTC via a beamsplitter. The model is then generalized further to account for the smooth transition to normal quantum mechanics as the CTC becomes much smaller than the size of the modes interacting on it. In this limit, we find that the system behaves like a standard quantum-mechanical feedback loop.

Pienaar, J. L.; Myers, C. R.; Ralph, T. C. [School of Mathematics and Physics, The University of Queensland, Brisbane 4072, Queensland (Australia)

2011-12-15T23:59:59.000Z

204

Hyperbolic monopoles, JNR data and spectral curves  

E-Print Network [OSTI]

A large class of explicit hyperbolic monopole solutions can be obtained from JNR instanton data, if the curvature of hyperbolic space is suitably tuned. Here we provide explicit formulae for both the monopole spectral curve and its rational map in terms of JNR data. Examples with platonic symmetry are presented, together with some one-parameter families with cyclic and dihedral symmetries. These families include hyperbolic analogues of geodesics that describe symmetric monopole scatterings in Euclidean space and we illustrate the results with energy density isosurfaces. There is a metric on the moduli space of hyperbolic monopoles, defined using the abelian connection on the boundary of hyperbolic space, and we provide a simple integral formula for this metric on the space of JNR data.

Stefano Bolognesi; Alex Cockburn; Paul Sutcliffe

2014-04-07T23:59:59.000Z

205

Energy Sources and Light Curves of Macronovae  

E-Print Network [OSTI]

A macronova (kilonova) was discovered with short gamma-ray burst, GRB 130603B, which is widely believed to be powered by the radioactivity of $r$-process elements synthesized in the ejecta of a neutron star binary merger. As an alternative, we propose that macronovae are energized by the central engine, i.e., a black hole or neutron star, and the injected energy is emitted after the adiabatic expansion of ejecta. This engine model is motivated by extended emission of short GRBs. In order to compare the theoretical models with observations, we analytically formulate the light curves of macronovae. The engine model allows a wider parameter range, especially smaller ejecta mass, and better fit to observations than the $r$-process model. Future observations of electromagnetic counterparts of gravitational waves should distinguish energy sources and constrain the activity of central engine and $r$-process nucleosynthesis.

Kisaka, Shota; Takami, Hajime

2014-01-01T23:59:59.000Z

206

Parameterization and applications of CatmullRom curves  

Science Journals Connector (OSTI)

The behavior of CatmullRom curves heavily depends on the choice of parameter values at the control points. We analyze a class of parameterizations ranging from uniform to chordal parameterization and show that, within this class, curves with centripetal parameterization contain properties that no other curves in this family possess. Researchers have previously indicated that centripetal parameterization produces visually favorable curves compared to uniform and chordal parameterizations. However, the mathematical reasons behind this behavior have been ambiguous. In this paper we prove that, for cubic CatmullRom curves, centripetal parameterization is the only parameterization in this family that guarantees that the curves do not form cusps or self-intersections within curve segments. Furthermore, we provide a formulation that bounds the distance of the curve to the control polygon and explain how globally intersection-free CatmullRom curves can be generated using these properties. Finally, we discuss two example applications of CatmullRom curves and show how the choice of parameterization makes a significant difference in each of these applications.

Cem Yuksel; Scott Schaefer; John Keyser

2011-01-01T23:59:59.000Z

207

Elevated Temperature Fracture Toughness and Fatigue Testing of Steels for Geothermal Applications  

SciTech Connect (OSTI)

Conventional drill bit steels exhibit increased wear and decreased toughness when run at elevated temperatures in geothermal wells. Bits are therefore run at lower speeds and lighter loads, resulting in lower penetration rates for geothermal drilling than for conventional rock drilling. Carpenter EX-00053, Timken CBS 600, Timken CBS 1000M and Vasco X-2M steels with improved hot hardness (improved wear resistance), were tested in conjunction with the steels used for cones (AISI 4829, 3915 and EX55) in conventional roller cones and lugs (AISI 8620, 9315 and EX55) in conventional roller cone rock bits. Short-rod fracture toughness measurements were made on each of these steels between room temperature and 400{degree}C. Fatigue crack resistance was determined at 300{degree}C for high-temperature steels and at room temperature for conventional steels. Scanning electron microscopy analyses of the fractured short-rod specimens were correlated with observed crack behavior from the test records. Materials testing results are discussed and steel selections made for improved geothermal bits. Carpenter EX-00053 and Timken CBS 1000M steels meet all design requirements for use in stabilizers, lugs and cones at temperatures to 400{degree}C. It is recommended that EX-00053 and CBS 1000M be manufactured for geothermal drilling at the Geysers site. [DJE 2005

Cutler, R.A.; Goodman, E.C.; Hendrickson, R.R.

1981-10-01T23:59:59.000Z

208

Ultrasonic detection of fatigue damage in glass-epoxy composites  

SciTech Connect (OSTI)

Energy storage flywheels fabricated of S2 glass-epoxy composite were studied to determine the behavior of the ultrasonic properties as a function of strain history and to identify possible predictors of incipient failure. Tensile specimens of the flywheel material were loaded uniaxially, and the ultrasonic properties (i.e., the shear and longitudinal wave velocities and the attenuation) were measured as a function of strain. Finished flywheels were similarly tested at various stages during cyclic spin testing; in addition, the polar backscattering intensity as a function of fatigue cycle was recorded. The velocities are excellent indicators of the maximum strain incurred at each point of the flywheel, and the attenuation delineates the region in which the stress is high enough to initiate microcracking in the matrix.

Simpson, W.A. Jr.; McClung, R.W.

1990-01-01T23:59:59.000Z

209

Engineering Predictions in Industrial and Power Flows Using the Retrograde Condensation Curve. Part I-Methodology  

E-Print Network [OSTI]

Industrial and power systems rely on engineering predictions of the flow properties of working fluids. The paper proposes a way of the utilization of the vapor quality values along the new retrograde condensation curve in the generation of the void fraction design guidelines and reliable prediction of the saturated liquid specific volumes/densities. The new procedure eliminates the involvement of semi-empirical relationships like rectilinear diameter and other similar models.

Labinov, Mark S

2014-01-01T23:59:59.000Z

210

Tafel slopes and corrosion rates obtained in the pre-Tafel region of polarization curves  

Science Journals Connector (OSTI)

A short review of previous attempts to determine Tafel slopes and corrosion rates from data obtained in the pre-Tafel region of polarization curves is followed by a description of the approach taken in the POLFIT program. Several examples are given of the application of this program including the use of factorial design experiments to determine the optimum conditions for formation of a chromate-free conversion coating on hot dipped galvanized steel.

Florian Mansfeld

2005-01-01T23:59:59.000Z

211

Artificial Neural Network Model for Prediction of Fatigue Lives of Composites Materials  

Science Journals Connector (OSTI)

The application of composites as engineering materials has become state of art and fatigue is one of the most complicated problems for fiber composites. The life prediction of a newly developed material is costly...

Sanjay Mathur; Prakash Chandra Gope

2007-01-01T23:59:59.000Z

212

Better postdiagnosis diet quality is associated with less cancer-related fatigue in breast cancer survivors  

Science Journals Connector (OSTI)

A comprehensive understanding of the role of modifiable health behaviors in effective management of cancer-related fatigue is needed. Among breast cancer survivors, we examined how postdiagnosis diet quality, ...

Stephanie M. George; Catherine M. Alfano

2014-12-01T23:59:59.000Z

213

Estimation of Fatigue Damage for an Austenitic Stainless Steel (SUS304) Using Magnetic Methods  

SciTech Connect (OSTI)

There are some fatigue damage estimation methods of the austenitic stainless steel that uses the martensitic transformation. For instance, they are the remanent magnetization method, the excitation method, and so on. Those two methods are being researched also in our laboratory now. In the remanent magnetization method, it is well known that the relation between fatigue damage and the remanent magnetization is simple, clear, and reproducible. However, this method has the disadvantage to need a special magnetizer. This method cannot be easily used on the site such as the factory. On the other hand, because the special magnetizer is unnecessary, the excitation method can use easily on the site. The output signal of this method is small. In this paper, two fatigue evaluation methods such as the remanent magnetization method and the excitation method are introduced. In addition, we report on the result of comparing the fatigue evaluation performances of two methods.

Oka, M. [Department of Computer and Control Engineering, Oita National College of Technology, 1666 Maki, Oita, 870-0152 (Japan); Yakushiji, T. [Department of Mechanical Engineering, Oita National College of Technology, 1666 Maki, Oita, 870-0152 (Japan); Tsuchida, Y.; Enokizono, M. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Oita University, 700 Dannoharu, Oita, 870-1192 (Japan)

2007-03-21T23:59:59.000Z

214

SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES  

E-Print Network [OSTI]

SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES damage in real size structural components of offshore wind turbines. KEYWORDS : Damage detection, Offshore wind turbines, Numerical response simulation. INTRODUCTION Offshore wind turbines are exposed

Paris-Sud XI, Université de

215

Analytical and Experimental Investigation for Distortion-Induced Fatigue in Steel Bridges  

E-Print Network [OSTI]

Distortion-induced fatigue has been extensively studied; however, retrofit techniques currently used are expensive and/or time consuming to implement. These retrofit techniques primarily fall into two categories--stiffening or softening the weak web...

Hartman, Amanda

2013-08-31T23:59:59.000Z

216

Repair of Steel Bridge Girders Damaged by Distortion-Induced Fatigue  

E-Print Network [OSTI]

Several studies have identified distortion-induced fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected...

Nagati, Amr Daniel

2012-08-31T23:59:59.000Z

217

Fatigue Enhancement of Category E' Detailsin Steel Bridge Girders Using CFRP Materials  

E-Print Network [OSTI]

Carbon Fiber Reinforced Polymer (CFRP) composite overlay elements were developed to improve the fatigue performance of Category E' steel details. By increasing the stiffness of the detail with the CFRP overlay, the stress demand at the weld...

Kaan, Benjamin Nicolaas

2008-01-01T23:59:59.000Z

218

Effect of stress ratio on fatigue life of GFRP composites for WT blade  

Science Journals Connector (OSTI)

Fatigue life of GFRP (glass-fiber reinforced plastic) composites used in wind turbine rotor blades has been evaluated considering the glass fiber orientations. Three different laminate composites with the resp...

Yong-Hak Huh; Jae-Hyun Lee; Dong-Jin Kim

2012-07-01T23:59:59.000Z

219

An analytical study of rail grinding optimization for rail-head fatigue defect prevention  

E-Print Network [OSTI]

and increased train traffic on the remaining routes. These changes in railroad industry practice have caused an increase in the rate of occurrence of rail head fatigue defects, one potential cause of train derailment. The primary form of maintenance employed...

Jones, Scott Laurence

1997-01-01T23:59:59.000Z

220

Influences of semiconductor morphology on the mechanical fatigue behavior of flexible organic electronics  

SciTech Connect (OSTI)

The influence of crystalline morphology on the mechanical fatigue of organic semiconductors (OSCs) was investigated using 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as a crystalline OSC and poly(triarylamine) (PTAA) as an amorphous OSC. During cyclic bending, resistances of the OSCs were monitored using the transmission-line method on a metal-semiconductor-metal structure. The resistance of the TIPS-pentacene increased under fatigue damage in tensile-stress mode, but no such degradation was observed in the PTAA. Both OSCs were stable under compressive bending fatigue. The formation of intergranular cracks at the domain boundaries of the TIPS-pentacene was responsible for the degradation of its electrical properties under tensile bending fatigue.

Lee, Young-Joo; Yeon, Han-Wool; Shin, Hae-A-Seul; Joo, Young-Chang, E-mail: ycjoo@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of); Uk Lee, Yong; Evans, Louise A. [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)] [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)

2013-12-09T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Fatigue of polycrystalline silicon for MEMS applications: Crack growth and stability under resonant loading conditions  

E-Print Network [OSTI]

S.B. , 1999. Subcritical crack growth in silicon MEMS. J.appearance of subcritical crack growth in the absence ofbe mistaken for subcritical fatigue-crack growth when the

Muhlstein, C.L.; Howe, R.T.; Ritchie, R.O.

2001-01-01T23:59:59.000Z

222

Environmental effects on fatigue and lifetime predictions for silica optical fibers  

E-Print Network [OSTI]

reliability of optical fibers is usually assessed using the subcritical crack growth model for fatigue defects (normally assumed to be cracks) to cause the defects to grow at applied stress levels which do

Matthewson, M. John

223

ECN GHG Marginal Abatement Cost curves (NAMAC) | Open Energy Information  

Open Energy Info (EERE)

ECN GHG Marginal Abatement Cost curves (NAMAC) ECN GHG Marginal Abatement Cost curves (NAMAC) Jump to: navigation, search Tool Summary Name: ECN GHG Marginal Abatement Cost curves for the Non-Annex I region (NAMAC) Agency/Company /Organization: Energy Research Centre of the Netherlands Sector: Energy, Land Topics: Resource assessment, Pathways analysis, Background analysis Website: www.ecn.nl/docs/library/report/2006/e06060.pdf References: GHG Marginal Abatement Cost curves for the Non-Annex I region[1] GHG Marginal Abatement Cost curves for the Non-Annex I region (NAMAC) (1999-present) ECN has developed a Marginal Abatement Cost curve containing detailed information on mitigation technologies and abatement costs in developing countries. * The MAC was first developed for the Dutch Ministry of Foreign

224

Design approaches for avoiding PWHT of North Sea offshore platforms  

SciTech Connect (OSTI)

This paper presents a review of the application of fracture mechanics to offshore platforms designed for the British sector North Sea. Since the earliest days post weld heat treatment (PWHT) has been extensively applied, in order to ensure adequate resistance to brittle fracture. The alternative approach, permitted by the regulations, of justifying leaving joints as-welded by the use of fracture mechanics, is also extensively practiced. This paper describes one design approach which is considered to account for the real behavior of engineering materials and which takes account of the reality of low toughness found in heat affected zones, the uncertainties of NDT practice and defect sizing and the pattern of residual stresses and fatigue crack growth behavior. The difficulties which arise are presented and the paper illustrates the dilemma that modern weight efficient structures are more likely to require PWHT than heavier structures with lower design stresses and longer fatigue lives.

Denney, A.K.; Barraclough, C.H.T. [John Brown Engineers and Constructors Ltd, London (United Kingdom). Materials and Welding Group

1996-12-01T23:59:59.000Z

225

D-Branes in Curved Space  

SciTech Connect (OSTI)

This thesis is a study of D-branes in string compactifications. In this context, D-branes are relevant as an important component of the nonperturbative spectrum, as an incisive probe of these backgrounds, and as a natural stringy tool for localizing gauge interactions. In the first part of the thesis, we discuss half-BPS D-branes in compactifications of type II string theory on Calabi-Yau threefolds. The results we describe for these objects are pertinent both in their role as stringy brane-worlds, and in their role as solitonic objects. In particular, we determine couplings of these branes to the moduli determining the closed-string geometry, both perturbatively and non-perturbatively in the worldsheet expansion. We provide a local model for transitions in moduli space where the BPS spectrum jumps, and discuss the extension of mirror symmetry between Calabi-Yau manifolds to the case when D-branes are present. The next section is an interlude which provides some applications of D-branes to other curved backgrounds of string theory. In particular, we discuss a surprising phenomenon in which fundamental strings moving through background Ramond-Ramond fields dissolve into large spherical D3-branes. This mechanism is used to explain a previously-mysterious fact discovered via the AdS-CFT correspondence. Next, we make a connection between type IIA string vacua of the type discussed in the first section and M-theory compactifications on manifolds of G{sub 2} holonomy. Finally we discuss constructions of string vacua which do not have large radius limits. In the final part of the thesis, we develop techniques for studying the worldsheets of open strings ending on the curved D-branes studied in the first section. More precisely, we formulate a large class of massive two-dimensional gauge theories coupled to boundary matter, which flow in the infrared to the relevant boundary conformal field theories. Along with many other applications, these techniques are used to describe world-volume theories of point-like D-probes of various Calabi-Yau threefolds.

McGreevy, John Austen; /Stanford U., Phys. Dept.

2005-07-06T23:59:59.000Z

226

Laboratory Evaluation of Hot-Mix Asphalt Concrete Fatigue Cracking Resistance  

E-Print Network [OSTI]

LABORATORY EVALUATION OF HOT-MIX ASPHALT CONCRETE FATIGUE CRACKING RESISTANCE A Thesis by BRANDON PARKER JAMISON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2010 Major Subject: Civil Engineering LABORATORY EVALUATION OF HOT-MIX ASPHALT CONCRETE FATIGUE CRACKING RESISTANCE A Thesis by BRANDON PARKER JAMISON Submitted to the Office of Graduate...

Jamison, Brandon Parker

2012-02-14T23:59:59.000Z

227

Creep-fatigue of High Temperature Materials for VHTR: Effect of Cyclic Loading and Environment  

SciTech Connect (OSTI)

Alloy 617 is the one of the leading candidate materials for Intermediate Heat eXchangers (IHX) of a Very High Temperature Reactor (VHTR). System start-ups and shut-downs as well as power transients will produce low cycle fatigue (LCF) loadings of components. Furthermore, the anticipated IHX operating temperature, up to 950C, is in the range of creep so that creep-fatigue interaction, which can significantly increase the fatigue crack growth, may be one of the primary IHX damage modes. To address the needs for Alloy 617 codification and licensing, a significant creep-fatigue testing program is underway at Idaho National Laboratory. Strain controlled LCF tests including hold times up to 1800s at maximum tensile strain were conducted at total strain range of 0.3% and 0.6% in air at 950C. Creep-fatigue testing was also performed in a simulated VHTR impure helium coolant for selected experimental conditions. The creep-fatigue tests resulted in failure times up to 1000 hrs. Fatigue resistance was significantly decreased when a hold time was added at peak stress and when the total strain was increased. The fracture mode also changed from transgranular to intergranular with introduction of a tensile hold. Changes in the microstructure were methodically characterized. A combined effect of temperature, cyclic and static loading and environment was evidenced in the targeted operating conditions of the IHX. This paper This paper reviews the data previously published by Carroll and co-workers in references 10 and 11 focusing on the role of inelastic strain accumulation and of oxidation in the initiation and propagation of surface fatigue cracks.

Celine Cabet; L. Carroll; R. Wright; R. Madland

2011-05-01T23:59:59.000Z

228

Design of Wind Turbines in an Area with Tropical Cyclones Niels-Erik Clausen, niels-erik.clausen@risoe.dk, Sren Ott, Niels-Jacob Tarp-Johansen, Per Nrgrd and  

E-Print Network [OSTI]

Design of Wind Turbines in an Area with Tropical Cyclones Niels-Erik Clausen, niels and cost of wind turbines is influenced by a combination of fatigue and extreme loads and the applied design codes. In general wind turbines are designed for 20 years of operation using design standards

229

Surface Patch Reconstruction via Curve Sampling Yan-Bin Jia  

E-Print Network [OSTI]

, a mouse, and a teapot to bigger ones such as a chair, a bike, and a car. The differentiability of a curved

Jia, Yan-Bin

230

Mechanisms for Fatigue of Micron-Scale Silicon StructuralFilms  

SciTech Connect (OSTI)

Although bulk silicon is not susceptible to fatigue,micron-scale silicon is. Several mechanisms have been proposed to explainthis surprising behavior although the issue remains contentious. Here wedescribe published fatigue results for micron-scale thin siliconfilms andfind that in general they display similar trends, in that lower cyclicstresses result in larger number of cycles to failure in stress-lifetimedata. We further show that one of two classes of mechanisms is invariablyproposed to explain the phenomenon. The first class attributes fatigue toa surface effect caused by subcritical (stable) cracking in thesilicon-oxide layer, e.g., reaction-layer fatigue; the second classproposes that subcritical cracking in the silicon itself is the cause offatigue in Si films. It is our contention that results to date fromsingle and poly crystalline silicon fatigue studies provide no convincingexperimentalevidence to support subcritical cracking in the silicon.Conversely, the reaction-layer mechanism is consistent with existingexperimental results, and moreover provides a rational explanation forthe marked difference in fatigue behavior of bulk and micron-scalesilicon.

Alsem, Daan Hein; Pierron, Olivier N.; Stach, Eric A.; Muhlstein,Christopher L.; Ritchie, Robert O.

2006-11-03T23:59:59.000Z

231

Aerodynamics of a rigid curved kite wing  

E-Print Network [OSTI]

A preliminary numerical study on the aerodynamics of a kite wing for high altitude wind power generators is proposed. Tethered kites are a key element of an innovative wind energy technology, which aims to capture energy from the wind at higher altitudes than conventional wind towers. We present the results obtained from three-dimensional finite volume numerical simulations of the steady air flow past a three-dimensional curved rectangular kite wing (aspect ratio equal to 3.2, Reynolds number equal to 3x10^6). Two angles of incidence -- a standard incidence for the flight of a tethered airfoil (6{\\deg}) and an incidence close to the stall (18{\\deg}) -- were considered. The simulations were performed by solving the Reynolds Averaged Navier-Stokes flow model using the industrial STAR-CCM+ code. The overall aerodynamic characteristics of the kite wing were determined and compared to the aerodynamic characteristics of the flat rectangular non twisted wing with an identical aspect ratio and section (Clark Y profil...

Maneia, Gianmauro; Tordella, Daniela; Iovieno, Michele

2013-01-01T23:59:59.000Z

232

Calibration curves for some standard Gap Tests  

SciTech Connect (OSTI)

The relative shock sensitivities of explosive compositions are commonly assessed using a family of experiments that can be described by the generic term ''Gap Test.'' Gap tests include a donor charge, a test sample, and a spacer, or gap, between two explosives charges. The donor charge, gap material, and test dimensions are held constant within each different version of the gap test. The thickness of the gap is then varied to find the value at which 50% of the test samples will detonate. The gap tests measure the ease with a high-order detonation can be established in the test explosive, or the ''detonability,'' of the explosive. Test results are best reported in terms of the gap thickness at the 50% point. It is also useful to define the shock pressure transmitted into the test sample at the detonation threshold. This requires calibrating the gap test in terms of shock pressure in the gap as a function of the gap thickness. It also requires a knowledge of the shock Hugoniot of the sample explosive. We used the 2DE reactive hydrodynamic code with Forest Fire burn rates for the donor explosives to calculate calibration curves for several gap tests. The model calculations give pressure and particle velocity on the centerline of the experimental set-up and provide information about the curvature and pulse width of the shock wave. 10 refs., 1 fig.

Bowman, A.L.; Sommer, S.C.

1989-01-01T23:59:59.000Z

233

Galaxy rotation curves in de Sitter space  

E-Print Network [OSTI]

The observed positive cosmological constant $\\Lambda$ and Hubble constant $H_0$ introduce a background of de Sitter gravitons of mass $m_0=\\sqrt{\\Lambda}\\hbar/c$ at a non-relativistic temperature $k_BT_{dS}=a_{H}\\hbar/\\pi c$, $a_H=H_0c$, where $\\hbar$ denotes the Planck constant and $c$ the velocity of light. In this cosmology, gravitational interactions are parameterized by the inverse temperature $\\beta=T_{dS}/T$ of the vacuum. The high and low $\\beta$ limits produce an acceleration $a\\simeq\\sqrt{a_Na_0}$, $a_0=2a_{H}/(1+\\beta_{dS})\\simeq 1.37\\times 10^{-8}$ cm s$^{-2}$, observed in observed galaxy rotation curves and, respectively, Newton's law. Gravitation may be anomalously weak in a transition about $2.17\\, {M_{11}^{1/2}} \\, \\mbox{kpc}$ around a galaxy of $M=M_{11}10^{11}M_\\odot$.

Maurice H. P. M. van Putten

2014-11-10T23:59:59.000Z

234

Ghost condensate model of flat rotation curves  

E-Print Network [OSTI]

An effective action of ghost condensate with higher derivatives creates a source of gravity and mimics a dark matter in spiral galaxies. We present a spherically symmetric static solution of Einstein--Hilbert equations with the ghost condensate at large distances, where flat rotation curves are reproduced in leading order over small ratio of two energy scales characterizing constant temporal and spatial derivatives of ghost field: $\\mu_*^2$ and $\\mu_\\star^2$, respectively, with a hierarchy $\\mu_\\star\\ll \\mu_*$. We assume that a mechanism of hierarchy is provided by a global monopole in the center of galaxy. An estimate based on the solution and observed velocities of rotations in the asymptotic region of flatness, gives $\\mu_*\\sim 10^{19}$ GeV and the monopole scale in a GUT range $\\mu_\\star\\sim 10^{16}$ GeV, while a velocity of rotation $v_0$ is determined by the ratio: $ \\sqrt{2} v_0^2= \\mu_\\star^2/\\mu_*^2$. A critical acceleration is introduced and naturally evaluated of the order of Hubble rate, that represents the Milgrom's acceleration.

V. V. Kiselev

2005-07-29T23:59:59.000Z

235

Growth factor parametrization in curved space  

SciTech Connect (OSTI)

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining cosmic acceleration. We explore here the inclusion of spatial curvature into the growth factor. We expand previous results using the approximation {omega}{sub m}{sup {gamma}} and then suggest a new form, f{sub a}={omega}{sub m}{sup {gamma}}+({gamma}-4/7){omega}{sub k}, as an approximation for the growth factor when the curvature {omega}{sub k} is not negligible, and where the growth index {gamma} is usually model dependent. The expression recovers the standard results for the curved and flat {lambda}CDM and Dvali-Gabadadze-Porrati models. Using the best fit values of {omega}{sub m0} and {omega}{sub k0} to the expansion/distance measurements from Type Ia SNe, baryon acoustic oscillation, WMAP5, and H(z) data, we fit the growth index parameter to current growth factor data and obtain {gamma}{sub {lambda}}({omega}{sub k}{ne}0)=0.65{sub -0.15}{sup +0.17} and {gamma}{sub DGP}({omega}{sub k}{ne}0)=0.53{sub -0.12}{sup +0.14}. For the {lambda}CDM model, the 1-{sigma} observational bounds are found consistent with theoretical value, unlike the case for the Dvali-Gabadadze-Porrati model. We also find that the current data we used is not enough to put significant constraints when the 3 parameters in f{sub a} are fit simultaneously. Importantly, we find that, in the presence of curvature, the analytical expression proposed for f{sub a} provides a better fit to the growth factor than other forms and should be useful for future high precision missions and studies.

Gong Yungui; Ishak, Mustapha; Wang Anzhong [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China) and Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Department of Physics, University of Texas at Dallas, Richardson, Texas 75083 (United States); CASPER, Physics Department, Baylor University, Waco, Texas 76798 (United States)

2009-07-15T23:59:59.000Z

236

Fabrication procedure effects on fatigue resistance of rib -to-deck welded joints of steel orthotropic bridge decks  

E-Print Network [OSTI]

International Orthotropic Bridge Conference (CD-ROM),fatigue evaluation of steel bridges. International Journalfor the Bronx-Whitestone Bridge rehabilitation. Journal of

Sim, Hyoung-Bo

2010-01-01T23:59:59.000Z

237

Thermal Shock Resistance (TSR) and Thermal Fatigue Resistance (TFR) of Refractory Materials. Evaluation Method Based on the Dynamic Elastic Modulus  

Science Journals Connector (OSTI)

The importance of the thermal shock resistance (TSR) of refractory material is discussed. Understanding the evolution of thermal ... undergo repeated thermal cycling. The thermal fatigue resistance (TFR) behavior...

Nicols M. Rendtorff; Esteban F. Aglietti

2014-01-01T23:59:59.000Z

238

The Effect of Muscle Fatigue of the Non-Paretic Limb on Postural Control of Stroke Patients .  

E-Print Network [OSTI]

??Since a significantly greater percentage of body weight is supported by the non-paretic limb following stroke, a greater amount of fatigue may be present during (more)

McEwen, Daniel W. D.

2011-01-01T23:59:59.000Z

239

Effect of Creep and Oxidation on Reduced Creep-Fatigue life of Ni-based Alloy 617 at 850 C  

SciTech Connect (OSTI)

Low cycle fatigue (LCF) and creep fatigue testing of Ni-based alloy 617 was carried out at 850 C. Compared with its LCF life, the material s creep fatigue life decreases to different extents depending on test conditions. To elucidate the microstructure-fatigue property relationship for alloy 617 and the effect of creep and oxidation on its fatigue life, systematic microstructural investigations were carried out using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction (EBSD). In LCF tests, as the total strain range increased, deformations concentrated near high angle grain boundaries (HAGBs). The strain hold period in the creep fatigue tests introduced additional creep damage to the material, which revealed the detrimental effect of the strain hold time on the material fatigue life in two ways. First, the strain hold time enhanced the localized deformation near HAGBs, resulting in the promotion of intergranular cracking of alloy 617. Second, the strain hold time encouraged grain boundary sliding, which resulted in interior intergranular cracking of the material. Oxidation accelerated the initiation of intergranular cracking in alloy 617. In the crack propagation stage, if oxidation was promoted and the cyclic oxidation damage was greater than the fatigue damage, oxidation-assisted intergranular crack growth resulted in a significant reduction in the material s fatigue life.

Chen, Xiang [ORNL] [ORNL; Yang, Zhiqing [ORNL] [ORNL; Sokolov, Mikhail A [ORNL] [ORNL; ERDMAN III, DONALD L [ORNL] [ORNL; Mo, Kun [ORNL] [ORNL; Stubbins, James [ORNL] [ORNL

2014-01-01T23:59:59.000Z

240

Towards quantum-resistant cryptosystems from supersingular elliptic curve isogenies  

Science Journals Connector (OSTI)

We present new candidates for quantum-resistant public-key cryptosystems based on the conjectured difficulty of finding isogenies between supersingular elliptic curves. The main technical idea in our scheme is that we transmit the images of torsion bases ... Keywords: elliptic curves, isogenies, quantum-resistant public-key cryptosystems

David Jao; Luca De Feo

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

NON-CLOSED CURVES IN Rn WITH FINITE TOTAL FIRST  

E-Print Network [OSTI]

], and Kondo and Tanaka [14] have examined the global properties of the total curvature of a curveNON-CLOSED CURVES IN Rn WITH FINITE TOTAL FIRST CURVATURE ARISING FROM THE SOLUTIONS OF AN ODE P finite total first curvature. If all the roots of the associated characteristic polynomial are simple, we

Gilkey, Peter B

242

Generic measures for geodesic flows on nonpositively curved manifolds  

E-Print Network [OSTI]

Generic measures for geodesic flows on nonpositively curved manifolds Yves Coud`ene, Barbara the generic invariant probability measures for the geodesic flow on connected complete nonpositively curved subset of the set of all probability measures invariant by the geodesic flow. The proof of K. Sigmund

Paris-Sud XI, Université de

243

Fast, Precise Flattening of Cubic Bzier Segment Offset Curves  

Science Journals Connector (OSTI)

A fast algorithm for generating a polyline approximation (flattening) for the offset curves of a cubic Bzier curve segment is described. It is shown to be more efficient than the standard recursive subdivision method by generating only 70% as many segments, ...

Thomas F. Hain; Sri Venkat R. Racherla; David D. Langan

2004-10-01T23:59:59.000Z

244

Optimizing rotational acceleration curves for minimum energy use in electric  

E-Print Network [OSTI]

Optimizing rotational acceleration curves for minimum energy use in electric motors. 12/15/06 Fall the optimal efficiency of a motor for any input values of motor constants, distance, or time. In every of the inspiration to find which rotational acceleration curve for the used motors would be most efficient. We really

Ruina, Andy L.

245

Stochastic Analysis of Wind Turbine Power Curves Edgar Anahua  

E-Print Network [OSTI]

of the wind turbine to its desired power production; and ii) the stochastic force (noise), whichStochastic Analysis of Wind Turbine Power Curves Edgar Anahua Oldenburg 2007 Zur Homepage der Dissertation #12;#12;Stochastic Analysis of Wind Turbine Power Curves Edgar Anahua Von der Fakult¨at f

Peinke, Joachim

246

Approximation of conic sections by curvature continuous quartic Bzier curves  

Science Journals Connector (OSTI)

In this paper we propose two approximation methods of conic section by quartic Bezier curves. These are the extensions of the quartic Bezier approximations of circular arcs presented in Ahn and Kim (1997) [1] and Kim and Ahn (2007) [10] to conic cases. ... Keywords: Approximation order, Conic section, Curvature continuity, Hausdorff distance, Quartic Bzier curves, Spline

Young Joon Ahn

2010-10-01T23:59:59.000Z

247

The Effect of Optimal Tuning of the Heating/Cooling Curve in AHU of HVAC System in Real Practice  

E-Print Network [OSTI]

too much energy is used but there are also more comfort- related complaints than expected. In order to optimise the energy consumption and to reduce the complaints there should be much more attention to the control strategy and the heating.../cooling curve. Paper 81, ICEBO 2004 TNO Bouw, The Netherlands Page: 3 of 12 Despite many years of optimisation of single components, such as condensing boilers, there is no common knowledge about how to design your control strategy or how to design...

2004-01-01T23:59:59.000Z

248

Curved mesh generation and mesh refinement using Lagrangian solid mechanics  

SciTech Connect (OSTI)

We propose a method for generating well-shaped curved unstructured meshes using a nonlinear elasticity analogy. The geometry of the domain to be meshed is represented as an elastic solid. The undeformed geometry is the initial mesh of linear triangular or tetrahedral elements. The external loading results from prescribing a boundary displacement to be that of the curved geometry, and the final configuration is determined by solving for the equilibrium configuration. The deformations are represented using piecewise polynomials within each element of the original mesh. When the mesh is sufficiently fine to resolve the solid deformation, this method guarantees non-intersecting elements even for highly distorted or anisotropic initial meshes. We describe the method and the solution procedures, and we show a number of examples of two and three dimensional simplex meshes with curved boundaries. We also demonstrate how to use the technique for local refinement of non-curved meshes in the presence of curved boundaries.

Persson, P.-O.; Peraire, J.

2008-12-31T23:59:59.000Z

249

Relative permeability of CBM reservoirs: Controls on curve shape  

Science Journals Connector (OSTI)

Relative permeability to gas and water for 2-phase flow coalbed methane (CBM) reservoirs has long been known to exhibit a strong control on (gas and water) production profile characteristics. Despite its important control on both primary and enhanced recovery of CBM for coal seams that have not been fully dewatered, relative permeability in coal has received little attention in the literature in the past decade. There are few published laboratory-derived curves; these studies and their resulting data represent a small subset of the commercial CBM reservoirs and do not allow for a systematic investigation of the physical controls on relative permeability curve shape. Other methods for estimation of relative permeability curves include derivation from simulation history-matching, and production data analysis. Both of these methods will yield pseudo-relative permeability curves whose shapes could be affected by several dynamic CBM reservoir and operating characteristics. The purpose of the current work is to perform a systematic investigation of the controls on CBM relative permeability curve shape, including non-static fracture permeability and porosity, multi-layer effects and transient flow. To derive the relative permeability curves, effective permeability to gas and water are obtained from flow equations, flow rates and pressure data. Simulated cases are analyzed so that derived and input curves may be compared allowing for investigation of CBM reservoir properties on curve shape. One set of relative permeability curves that were input into the simulator were obtained from pore-scale modeling. Field cases from two basins are also examined and controls on derived relative permeability curve shape inferred. The results of this work should be useful for future CBM development and greenhouse gas sequestration studies, and it is hoped that it will spark additional research of this critical CBM flow property.

C.R. Clarkson; M. Rahmanian; A. Kantzas; K. Morad

2011-01-01T23:59:59.000Z

250

Predicting overload-affected fatigue crack growth in steels  

SciTech Connect (OSTI)

The ability of semi-empirical crack closure models to predict the effect of overloads on fatigue crack growth in low-alloy steels has been investigated. With this purpose, the CORPUS model developed for aircraft metals and spectra has been checked first through comparisons between the simulated and observed results for a low-alloy steel. The CORPUS predictions of crack growth under several types of simple load histories containing overloads appeared generally unconservative which prompted the authors to formulate a new model, more suitable for steels. With the latter approach, the assumed evolution of the crack opening stress during the delayed retardation stage has been based on experimental results reported for various steels. For all the load sequences considered, the predictions from the proposed model appeared to be by far more accurate than those from CORPUS. Based on the analysis results, the capability of semi-empirical prediction concepts to cover experimentally observed trends that have been reported for sequences with overloads is discussed. Finally, possibilities of improving the model performance are considered.

Skorupa, M.; Skorupa, A.; Ladecki, B. [Univ. of Mining and Metallurgy, Krakow (Poland). Dept. of Mechanical Engineering and Robotics

1996-12-01T23:59:59.000Z

251

Novel Experiments to Characterize Creep-Fatigue Degradation in VHTR Alloys  

SciTech Connect (OSTI)

It is well known in energy systems that the creep lifetime of high temperature alloys is significantly degraded when a cyclic load is superimposed on components operating in the creep regime. A test method has been developed in an attempt to characterize creep-fatigue behavior of alloys at high temperature. The test imposes a hold time during the tensile phase of a fully reversed strain-controlled low cycle fatigue test. Stress relaxation occurs during the strain-controlled hold period. This type of fatigue stress relaxation test tends to emphasize the fatigue portion of the total damage and does not necessarily represent the behavior of a component in-service well. Several different approaches to laboratory testing of creep-fatigue at 950C have been investigated for Alloy 617, the primary candidate for application in VHTR heat exchangers. The potential for mode switching in a cyclic test from strain control to load control, to allow specimen extension by creep, has been investigated to further emphasize the creep damage. In addition, tests with a lower strain rate during loading have been conducted to examine the influence of creep damage occurring during loading. Very short constant strain hold time tests have also been conducted to examine the influence of the rapid stress relaxation that occurs at the beginning of strain holds.

J. K. Wright; J. A. Simpson; L. J. Carroll; R. N. Wright; T.-L. Sham

2013-10-01T23:59:59.000Z

252

Acoustic Emission Detection and Prediction of Fatigue Crack Propagation in Composite Patch Repairs Using Neural Networks  

SciTech Connect (OSTI)

An aircraft is subjected to severe structural and aerodynamic loads during its service life. These loads can cause damage or weakening of the structure especially for aging military and civilian aircraft, thereby affecting its load carrying capabilities. Hence composite patch repairs are increasingly used to repair damaged aircraft metallic structures to restore its structural efficiency. This paper presents the results of Acoustic Emission (AE) monitoring of crack propagation in 2024-T3 Clad aluminum panels repaired with adhesively bonded octagonal, single sided boron/epoxy composite patch under tension-tension fatigue loading. Crack propagation gages were used to monitor crack initiation. The identified AE sensor features were used to train neural networks for predicting crack length. The results show that AE events are correlated with crack propagation. AE system was able to detect crack propagation even at high noise condition of 10 Hz loading; that crack propagation signals can be differentiated from matrix cracking signals that take place due to fiber breakage in the composite patch. Three back-propagation cascade feed forward networks were trained to predict crack length based on the number of fatigue cycles, AE event number, and both the Fatigue Cycles and AE events, as inputs respectively. Network using both fatigue cycles and AE event number as inputs to predict crack length gave the best results, followed by Network with fatigue cycles as input, while network with just AE events as input had a greater error.

Okafor, A. Chukwujekwu; Singh, Navdeep; Singh, Navrag [Structural Health Monitoring and NDE Laboratory, Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, 1870 Miner Circle Rolla MO 65409-0050 (United States)

2007-03-21T23:59:59.000Z

253

21-PWR WASTE PACKAGE WITH ABSORBER PLATES LOADING CURVE EVALUATION  

SciTech Connect (OSTI)

The objective of this calculation is to evaluate the required minimum burnup as a function of initial pressurized water reactor (PWR) assembly enrichment that would permit loading of spent nuclear fuel into the 21 PWR waste package with absorber plates design as provided in Attachment IV. This calculation is an example of the application of the methodology presented in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003). The scope of this calculation covers a range of enrichments from 0 through 5.0 weight percent U-235, and a burnup range of 0 through 45 GWd/MTU. Higher burnups were not necessary because 45 GWd/MTU was high enough for the loading curve determination. This activity supports the validation of the use of burnup credit for commercial spent nuclear fuel applications. The intended use of these results will be in establishing PWR waste package configuration loading specifications. Limitations of this evaluation are as follows: (1) The results are based on burnup credit for actinides and selected fission products as proposed in YMP (2003, Table 3-1) and referred to as the ''Principal Isotopes''. Any change to the isotope listing will have a direct impact on the results of this report. (2) The results are based on 1.5 wt% Gd in the Ni-Gd Alloy material and having no tuff inside the waste package. If the Gd loading is reduced or a process to introduce tuff inside the waste package is defined, then this report would need to be reevaluated based on the alternative materials. This calculation is subject to the ''Quality Assurance Requirements and Description'' (QARD) (DOE 2004) because it concerns engineered barriers that are included in the ''Q-List'' (BSC 2004k, Appendix A) as items important to safety and waste isolation.

J.M. Scaglione

2004-12-17T23:59:59.000Z

254

Stress intensity factors and fatigue growth of a surface crack in a drill pipe during rotary drilling operation  

E-Print Network [OSTI]

known that drill pipe fatigue in oil-gas drilling operations represents more than 30% of the drill pipeStress intensity factors and fatigue growth of a surface crack in a drill pipe during rotary drilling operation Ngoc Ha Daoa, , Hedi Sellamia aMines ParisTech, 35 rue Saint-Honoré, 77305 Fontainebleau

Paris-Sud XI, Université de

255

Materials Science and Engineering A231 (1997) 170182 Fatigue crack growth resistance in SiC particulate and whisker  

E-Print Network [OSTI]

Materials Science and Engineering A231 (1997) 170­182 Fatigue crack growth resistance in Si resulted in higher crack growth resistance at low growth rates in the particulate reinforced materials in these materials have indicated that many factors may be important in deter- mining the fatigue resistance of SiC/

Ritchie, Robert

256

Fatigue Life of Damaged Bridge Deck Panels Strengthened With Carbon Fiber Hongseob Oh, Jongsung Sim, and Christian Meyer  

E-Print Network [OSTI]

1 Fatigue Life of Damaged Bridge Deck Panels Strengthened With Carbon Fiber Sheets Hongseob Oh was applied to test panels, which were then reinforced with carbon fiber sheets (CFS) using two different for bridge decks, based on cumulative damage theory. Keywords: bridge deck slab, carbon fiber sheets, fatigue

Meyer, Christian

257

Vuillerme and Boisgontier, Gait and Posture (2008) doi:10.1016/j.gaitpost.2008.03.005 MUSCLE FATIGUE DEGRADES FORCE SENSE AT THE ANKLE JOINT  

E-Print Network [OSTI]

FATIGUE DEGRADES FORCE SENSE AT THE ANKLE JOINT Nicolas VUILLERME and Matthieu BOISGONTIER Laboratoire of muscle fatigue on force sense at the ankle joint, ten young healthy adults were asked to perform an isometric contra-lateral force ankle-matching task in two experimental conditions of (1) No-fatigue and (2

Paris-Sud XI, Université de

258

Residual stress profiles for mitigating fretting fatigue in gas turbine engine disks  

Science Journals Connector (OSTI)

The driving force for fretting fatigue in engine disks is the contact stresses generated by fretting of the blade and the disk surfaces in the attachment region. This paper examines the use of different residual compressive stress profiles to counteract the undesirable effects of contact stresses and to mitigate fretting fatigue. A global finite-element analysis of the disk blade assembly is first performed. The contact pressure and shear traction at the attachment region are extracted from the FEM results and used to compute the contact stress distribution. The contact stresses are then combined with the residual stresses and the bulk stresses. The overall stress distribution is then utilized in a probabilistic crack growth model to predict the risk of disk failure for a military engine under simulated loading conditions. The results are used to identify the minimum residual stress profile for mitigating fretting fatigue in engine disks.

Kwai S. Chan; Michael P. Enright; Jonathan P. Moody; Patrick J. Golden; Ramesh Chandra; Alan C. Pentz

2010-01-01T23:59:59.000Z

259

A simple method of estimating wind turbine blade fatigue at potential wind turbine sites  

SciTech Connect (OSTI)

This paper presents a technique of estimating blade fatigue damage at potential wind turbine sites. The cornerstone of this technique is a simple model for the blade`s root flap bending moment. The model requires as input a simple set of wind measurements which may be obtained as part of a routine site characterization study. By using the model to simulate a time series of the root flap bending moment, fatigue damage rates may be estimated. The technique is evaluated by comparing these estimates with damage estimates derived from actual bending moment data; the agreement between the two is quite good. The simple connection between wind measurements and fatigue provided by the model now allows one to readily discriminate between damaging and more benign wind environments.

Barnard, J.C.; Wendell, L.L.

1995-06-01T23:59:59.000Z

260

Effects of wear-resistant coatings on the fatigue strength of 4340 steel  

SciTech Connect (OSTI)

For applications using 4340 steel where hardened surfaces are required in a marine environment, surface coatings are necessary. Coatings that resist corrosion and provide wear resistance generally degrade the fatigue performance of the substrate metal. Shot peening before plating was ineffective in preventing a loss of fatigue life of plated steel bars compared to bare steel test bars which were not shot peened. The maximum residual compressive strength produced by shot peening was measured and was less than the maximum applied tensile stress in fatigue. As-plated electroless nickel has poor sliding wear resistance compared to either electroplated nickel or chromium in sliding wear at a contact stress of 37 Mpa. The tensile strength decreased in proportion to the volume fraction of coating applied to the steel substrate.

Duffy, E.R. [Naval Aviation Depot North Island, San Diego, CA (United States)

1998-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint  

SciTech Connect (OSTI)

Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

2011-12-01T23:59:59.000Z

262

Rutting and drainage design methodology for a concrete block pavement  

E-Print Network [OSTI]

. . . . 2 Experience based design chart used in Denmark. . . . . 10 3 Experience based design chart used in South Africa. . . . . . . . . . . . . . 4 Marais' design curve based on Westergaard's slab theory. . . . . 12 5 CCA design chart used in Great... 150 Fi 3 ? Ex erience based desi n chart used in South Africa. ' ~ Modifications Based On Existing Design Procedures For Pavements One of the first design procedures for concrete block pavements was developed by Marais in 1967 and based on rigid...

Poduska, Daryl Jason

1998-01-01T23:59:59.000Z

263

DOE Updated U.S. Geothermal: Supply Curve (Presentation)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2009 DOE GEOTHERMAL SUPPLY CURVE UPDATE: Prepared by the National Renewable Energy Laboratory (NREL) 2009 DOE GEOTHERMAL SUPPLY CURVE UPDATE: Prepared by the National Renewable Energy Laboratory (NREL) eere.energy.gov The Parker Ranch installation in Hawaii Geothermal Technologies Program (GTP) DOE Updated U.S. Geothermal Supply Curve Chad Augustine National Renewable Energy Laboratory Strategic Energy Analysis Center Chad.Augustine@nrel.gov February 1, 2010 Chad Augustine (NREL) Katherine R. Young (NREL) Arlene Anderson (DOE-GTP) NREL/PR-6A2-47527 Pacific Gas & Electric/PIX 00059 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 2 | 2009 DOE GEOTHERMAL SUPPLY CURVE UPDATE: Prepared by the National Renewable Energy Laboratory (NREL) eere.energy.gov

264

ROTATION CURVES OF 967 SPIRAL GALAXIES: IMPLICATIONS FOR DARK MATTER.  

E-Print Network [OSTI]

We present the rotation curves of 967 spiral galaxies, obtained by deprojecting and folding the raw data published by Mathewson et al. (1992). Of these, 80 meet objective excellence criteria and are suitable for individual detailed mass modelling, while 820 are suitable for statistical studies. A preliminary analysis of theire properties confirms that rotation curves are a universal function of luminosity and that the dark matter fraction in spirals increase with decreasing luminosity. Quantitative considerations on the virial radius of dark halos allow us to make hypotheses about their structure and nature. The deprojected folded curves, the smoothed curves, and various related quantities are available via anonymous ftp at ftp://galileo.sissa.it/users/ftp/pub/psrot

Massimo Persic; Paolo Salucci; Fulvio Stel

1995-03-13T23:59:59.000Z

265

Comparison of Emperical Decline Curve Analysis for Shale Wells  

E-Print Network [OSTI]

This study compares four recently developed decline curve methods and the traditional Arps or Fetkovich approach. The four methods which are empirically formulated for shale and tight gas wells are: 1. Power Law Exponential Decline (PLE). 2...

Kanfar, Mohammed Sami

2013-07-13T23:59:59.000Z

266

A general method for generating parametric Lorenz and Leimkuhler curves  

Science Journals Connector (OSTI)

Let L 0 consider an initial Lorenz curve. In this paper we propose a general methodology for obtaining new classes of parametric Lorenz or Leimkuhler curves that contain the original curve as limiting or special case. The new classes introduce additional parameters in the original family, providing more flexibility for the new families. The new classes are built from an ordered sequence of power Lorenz curves, assuming that the powers are distributed according to some convenient discrete random variable. Using this method we obtain many of the families proposed in the literature, including the classical proposal of Bradford (1934), Kakwani and Podder (1973) and others. We obtain some inequality measures and population functions for the proposed families.

Jos Mara Sarabia; Emilio Gmez-Dniz; Mara Sarabia; Faustino Prieto

2010-01-01T23:59:59.000Z

267

Note on Kakwani and Podder Method of Fitting Lorenz Curves  

Science Journals Connector (OSTI)

The Lorenz curve is a useful device to depict the characteristics of income and wealth distributions in terms of the degree of equality of the underlying distribution. In practice, income (or wealth) data by i...

Gilbert S. Suzawa

1983-01-01T23:59:59.000Z

268

Plastic energy dissipation model for lifetime prediction of zirconium and zircaloy-4 fatigued at RT and 400 C  

SciTech Connect (OSTI)

Zirconium and zircaloy-4 are generally used as fuel tubes in pressurized heavy water reactors because of their low neutron absorption cross-section, excellent corrosion resistance, good strength and ductility. Low cycle fatigue properties of zirconium and zircaloy-4 were investigated at RT and 400 C. The microscopic structure was determined using scanning electron microscopy and transmission electron microscopy techniques. On the basis of analyses of fatigue damage mechanism, it is believed that fatigue is an irreversible energy dissipation process. Thus, the plastic dissipation energy per cycle is selected as a fatigue damage variable. The accumulated plastic dissipation energy is calculated at the condition of considering cyclic hardening, saturation and softening characters of zirconium and zircaloy-4 during cycling. The testing results show that they present a power law between the plastic dissipation energy and fatigue lifetime.

Lin, X.; Haicheng, G. [Xi`an Jiaotong Univ. (China). State Key Lab. for Mechanical Behavior of Materials

1998-04-01T23:59:59.000Z

269

On the modular curve X0(23) Rene Schoof  

E-Print Network [OSTI]

that the extension does not split over Z[ 1 23 ]. The group scheme J0(23)[2] even has irreducible featuresOn the modular curve X0(23) Ren´e Schoof Abstract. The Jacobian J0(23) of the modular curve X0(23) is a semi-stable abelian variety over Q with good reduction outside 23. It is simple. We prove that every

Schoof, René

270

An analysis of muscle fatigue due to complex tasks and its relation to the strain index  

E-Print Network [OSTI]

will be used to recover the EMG signal (Bilodeau et al, 2003; Blackwell et al, 1999; Mogk and Keir, 2003; Moritani et al, 1986a; Petrofsky, 1981; Radwin and Ruffalo, 1999; West et al, 1995). RMS amplitude is commonly used to characterize the EMG signal...? (West et al, 1995). Because of their effect on a subject?s perception of fatigue, these subjective factors need to be incorporated into fatigue studies. Localized discomfort surveys and ratings of perceived exertions (RPE) are two different types...

Stephens, John-Paul

2009-06-02T23:59:59.000Z

271

Effect of residual stress and surface roughness on the fatigue behaviour of aluminium matrix composites  

Science Journals Connector (OSTI)

In this investigation the fatigue properties of specimens manufactured with different turning parameters were investigated in stress-controlled constant amplitude tests at ambient temperature. The change of feed rate and depth of cut lead to a change in the near surface microstructure. Hence the fatigue properties were influenced significantly due to different surface roughness and surface residual stress resulting from the unequal turning processes. The cyclic deformation behaviour of AMC225xe is characterised by pronounced initial cyclic hardening. Continuous load increase tests allow a reliable estimation of the endurance limit of AMC225xe with one single specimen on the basis of cyclic deformation, temperature and electrical resistance data.

M Smaga; D Eifler

2010-01-01T23:59:59.000Z

272

Analysis of the effect of matrix degradation on fatigue behavior of a graphite/epoxy laminate  

E-Print Network [OSTI]

ANALYSIS OF THE EFFECT OF MATRIX DEGRADATION ON FATIGUE BEHAVIOR OF A GRAPHITE/EPOXY LAMINATE A Thesis by ROBERT THOMAS ARENBURG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1982 Major Subject: Civil Engineering ANALYSiS OF THE EFFECT OF MATRIX DEGRAOATION ON FATIGUE BEHAVIOR OF A GRAPHITE/EPOXY LAMINATE A Thesis by ROBERT THOMAS ARENBURG Approved as to style and content by: (Chairman...

Arenburg, Robert Thomas

2012-06-07T23:59:59.000Z

273

Failure by fracture and fatigue in 'NANO' and 'BIO'materials  

SciTech Connect (OSTI)

The behavior of nanostructured materials/small-volumestructures and biologi-cal/bio-implantable materials, so-called "nano"and "bio" materials, is currently much in vogue in materials science. Oneaspect of this field, which to date has received only limited attention,is their fracture and fatigue properties. In this paper, we examine twotopics in this area, namely the premature fatigue failure ofsilicon-based micron-scale structures for microelectromechanical systems(MEMS), and the fracture properties of mineralized tissue, specificallyhuman bone.

Ritchie, R.O.; Muhlstein, C.L.; Nalla, R.K.

2003-12-19T23:59:59.000Z

274

One-Year Longitudinal Study of Fatigue, Cognitive Functions, and Quality of Life After Adjuvant Radiotherapy for Breast Cancer  

SciTech Connect (OSTI)

Purpose: Most patients with localized breast cancer (LBC) who take adjuvant chemotherapy (CT) complain of fatigue and a decrease in quality of life during or after radiotherapy (RT). The aim of this longitudinal study was to compare the impact of RT alone with that occurring after previous CT on quality of life. Methods and Materials: Fatigue (the main endpoint) and cognitive impairment were assessed in 161 CT-RT and 141 RT patients during RT and 1 year later. Fatigue was assessed with Functional Assessment of Cancer Therapy-General questionnaires, including breast and fatigue modules. Results: At baseline, 60% of the CT-RT patients expressed fatigue vs. 33% of the RT patients (p <0.001). Corresponding values at the end of RT were statistically similar (61% and 53%), and fatigue was still reported at 1 year by more than 40% of patients in both groups. Risk factors for long-term fatigue included depression (odds ratio [OR] = 6), which was less frequent in the RT group at baseline (16% vs. 28 %, respectively, p = 0.01) but reached a similar value at the end of RT (25% in both groups). Initial mild cognitive impairments were reported by RT (34 %) patients and CT-RT (24 %) patients and were persistent at 1 year for half of them. No biological disorders were associated with fatigue or cognitive impairment. Conclusions: Fatigue was the main symptom in LBC patients treated with RT, whether they received CT previously or not. The correlation of persistent fatigue with initial depressive status favors administering medical and psychological programs for LBC patients treated with CT and/or RT, to identify and manage this main quality-of-life-related symptom.

Noal, Sabine [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Clinical Research Department, Centre Francois Baclesse, Caen (France); Levy, Christelle [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Hardouin, Agnes [Department of Medical Biology, Centre Francois Baclesse, Caen (France); Rieux, Chantal [Clinical Research Department, Centre Francois Baclesse, Caen (France); Heutte, Natacha [Universite de Caen Basse Normandie GRECAN, Caen (France); Segura, Carine [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Collet, Fabienne [Clinical Research Department, Centre Francois Baclesse, Caen (France); Allouache, Djelila; Switsers, Odile; Delcambre, Corinne; Delozier, Thierry [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Henry-Amar, Michel [Clinical Research Department, Centre Francois Baclesse, Caen (France); Joly, Florence, E-mail: f.joly@baclesse.fr [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Clinical Research Department, Centre Francois Baclesse, Caen (France); CHU, Cote de Nacre, Caen (France)

2011-11-01T23:59:59.000Z

275

Sandia National Laboratories: Composite-Materials Fatigue Database...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Plan Webinar Wednesday, Jan. 14 Sandian Presents on PV Failure Analysis at European PV Solar Energy Conference and Exhibition (EU PVSC) EC Top Publications Design and Analysis for...

276

Automatic synthesis of quantum circuits for point addition on ordinary binary elliptic curves  

E-Print Network [OSTI]

Implementing the group arithmetic is a cost-critical task when designing quantum circuits for Shor's algorithm to solve the discrete logarithm problem. We introduce a tool for the automatic generation of addition circuits for ordinary binary elliptic curves, a prominent platform group for digital signatures. Our Python software generates circuit descriptions that, without increasing the number of qubits or T-depth, involve less than 39% of the number of T-gates in the best previous construction. The software also optimizes the (CNOT) depth for GF(2)-linear operations by means of suitable graph colorings.

Parshuram Budhathoki; Rainer Steinwandt

2014-01-10T23:59:59.000Z

277

Design for manufacturability Design verification  

E-Print Network [OSTI]

ITRS Design #12;Design · Design for manufacturability · Design verification #12;Design for Manufacturability · Architecture challenges · Logic and circuit challenges · Layout and physical design challenges · Expected to be the source of multiple DFM challenges · Invest in variability reduction or design

Patel, Chintan

278

NREL: Computational Science - Inverse Design  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Inverse Design Inverse Design The NREL Computational Science Center collaborates with the High Throughput and Inverse Band Structure (HT/IBS) Group within the Center for Inverse Design (CID) to research, design, and create materials with given target properties. The Center for Inverse Design is an Energy Frontier Research Center of the U.S. Department of Energy Office of Science. To address a crucial scientific grand challenge, the Center is pursuing a new approach to material science. Rather than using the conventional direct approach ("Given the structure, find the electronic properties"), we are using a "materials by inverse design" approach ("Given the desired property, find the structure"). Illustration of a blue arrow pointing to a graphic with three curved lines that represent an electronic structure and blue arrow pointing to a red and blue balls that represent an atomic configuration.

279

Atomistic modeling of nanowires, small-scale fatigue damage in cast magnesium, and materials for MEMS.  

SciTech Connect (OSTI)

Lightweight and miniaturized weapon systems are driving the use of new materials in design such as microscale materials and ultra low-density metallic materials. Reliable design of future weapon components and systems demands a thorough understanding of the deformation modes in these materials that comprise the components and a robust methodology to predict their performance during service or storage. Traditional continuum models of material deformation and failure are not easily extended to these new materials unless microstructural characteristics are included in the formulation. For example, in LIGA Ni and Al-Si thin films, the physical size is on the order of microns, a scale approaching key microstructural features. For a new potential structural material, cast Mg offers a high stiffness-to-weight ratio, but the microstructural heterogeneity at various scales requires a structure-property continuum model. Processes occurring at the nanoscale and microscale develop certain structures that drive material behavior. The objective of the work presented in this report was to understand material characteristics in relation to mechanical properties at the nanoscale and microscale in these promising new material systems. Research was conducted primarily at the University of Colorado at Boulder to employ tightly coupled experimentation and simulation to study damage at various material size scales under monotonic and cyclic loading conditions. Experimental characterization of nano/micro damage will be accomplished by novel techniques such as in-situ environmental scanning electron microscopy (ESEM), 1 MeV transmission electron microscopy (TEM), and atomic force microscopy (AFM). New simulations to support experimental efforts will include modified embedded atom method (MEAM) atomistic simulations at the nanoscale and single crystal micromechanical finite element simulations. This report summarizes the major research and development accomplishments for the LDRD project titled 'Atomistic Modeling of Nanowires, Small-scale Fatigue Damage in Cast Magnesium, and Materials for MEMS'. This project supported a strategic partnership between Sandia National Laboratories and the University of Colorado at Boulder by providing funding for the lead author, Ken Gall, and his students, while he was a member of the University of Colorado faculty.

Dunn, Martin L. (University of Colorado, Boulder, CO); Talmage, Mellisa J. (University of Colorado, Boulder, CO); McDowell, David L., 1956- (,-Georgia Institute of Technology, Atlanta, GA); West, Neil (University of Colorado, Boulder, CO); Gullett, Philip Michael (Mississippi State University , MS); Miller, David C. (University of Colorado, Boulder, CO); Spark, Kevin (University of Colorado, Boulder, CO); Diao, Jiankuai (University of Colorado, Boulder, CO); Horstemeyer, Mark F. (Mississippi State University , MS); Zimmerman, Jonathan A.; Gall, K (Georgia Institute of Technology, Atlanta, GA)

2006-10-01T23:59:59.000Z

280

HYPERELLIPTIC CURVES IN CHARACTERISTIC 2 JASPER SCHOLTEN AND HUI JUNE ZHU  

E-Print Network [OSTI]

HYPERELLIPTIC CURVES IN CHARACTERISTIC 2 JASPER SCHOLTEN AND HUI JUNE ZHU Abstract. In this paper. Supersingular curve, hyperelliptic curve, Newton polygon. 1 #12;2 JASPER SCHOLTEN AND HUI JUNE ZHU Section 2

Zhu, Hui June

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION  

E-Print Network [OSTI]

Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel

Yee, G.

2010-01-01T23:59:59.000Z

282

A quantum theory of distance along a curve  

E-Print Network [OSTI]

We present a quantum theory of distances along a curve, based on a linear line element that is equal to the operator square root of the quadratic metric of Riemannian geometry. Since the linear line element is an operator, we treat it according to the rules of quantum mechanics and interpret its eigenvalues as physically observable distances; the distance eigenvalues are naturally quantized. There are both positive and negative eigenvalues, which requires interpretation. Multi-element curves are defined as direct sums of line elements, and behave much like systems of spin half electrons in a magnetic field. For a curve of many elements an entropy and energy and temperature are quite naturally defined, leading via standard statistical thermodynamics to a relation between the most probable curve length and temperature. That relation may be viewed as a universal heat-shrinking property of curves. At this stage of the theory we do not include bodies or particles in the mix, do not suggest field equations for the quantum geometry, and questions of interpretation remain. The theory might conceivably be testable using observations of the early Universe, when the temperature of space was presumably quite high. In particular cosmogenesis may be thought of as time stopping at an infinite temperature as we go backwards in time to the beginning.

Ronald J. Adler

2014-02-13T23:59:59.000Z

283

Stress dependent activation entropy for dynamic fatigue of pristine silica optical fibers  

E-Print Network [OSTI]

Subcritical crack growth in fused silica is treated as a stress assisted chemical reaction between water distilled water and pH 7 buffer solution, and the results are found to be similar. The fatigue parameters to the barrier height. The results show subcritical crack growth in high strength silica is dominated by entropy

Matthewson, M. John

284

Characterization and Modeling of Transformation Induced Fatigue of Shape Memory Alloy Actuators  

E-Print Network [OSTI]

to conduct repeatable and reliable fatigue testing. For this research, two materials are being investigated: TiNiCu and Ni-rich NiTi. The experiments performed on the first selected alloy, i.e. TiNiCu SMA, explore three major parameters: the applied stress...

Bertacchini, Olivier Walter

2011-02-22T23:59:59.000Z

285

Fatigue and delayed brittle failure of vacuum melted and cadmium plated steel  

Science Journals Connector (OSTI)

The detrimental effect of cyanide cadmium plating on fatigue strength and delayed brittle failure performance of an ultra high strength steel is reduced effectively by using vacuum melted steel as the basis metal. This phenomenon has been related predominantly to the increased tensile ductility of the steel with comparatively low hydrogen concentration.

W. Beck; E.J. Jankowsky; W.H. Golding

1967-01-01T23:59:59.000Z

286

Fatigue behavior of silicon carbide reinforced titanium (Ti/SCS-6) metal matrix composites  

SciTech Connect (OSTI)

Flexure fatigue behavior was investigated on titanium (Ti-15V-3Cr) metal matrix composites reinforced with cross-poly, continuous silicon carbide (SiC) fibers. The Ti/SCS-6 composites had an 8-ply, (0{degree}, 90{degree}, +45{degree}, {minus}45{degree}), symmetric lay-up. During fatigue testing, four stages of flexure deflection behavior were observed. The deflection at stage 1 increased slightly with fatigue cycling, while that at stage 2 increased significantly with cycling. Interestingly, the deflection at stage 3 again increased negligibly with fatigue cycling. Stage 4 was associated with final failure, and the deflection increased abruptly. In the stage 1 region of the deflection behavior, no cracks were observed, the Ti/SiC interface debonding could be present, and the deflection changed slightly with cycling. When the stage 2 region commenced, cracks began to initiate. As stage 2 progressed, both crack density and crack length increased. The increased crack density and crack length contributed to the great increase in the deflection during stage 2. In stage 3, significant crack deflection and branching, and fiber bridging occurred, and crack density remained relatively constant. Crack deflection and branching, and fiber bridging slowed down crack driving force, and little crack extension was observed, which resulted in an insignificant amount of increase in the stage 3 deflection. The breakage of fibers in stage 4 significantly increased deflection.

Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering] [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Diaz, E.S. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)] [Westinghouse Science and Technology Center, Pittsburgh, PA (United States); Chiang, K.T.; Loh, D.H. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.] [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

1995-05-15T23:59:59.000Z

287

BAYESIAN UPDATING OF PROBABILISTIC TIME-DEPENDENT FATIGUE MODEL: APPLICATION TO JACKET FOUNDATIONS OF WIND TURBINES  

E-Print Network [OSTI]

OF WIND TURBINES Benjamin Rocher1,2 , Franck Schoefs1 , Marc François1 , Arnaud Salou2 1 LUNAM Université.rocher@univ-nantes.fr ABSTRACT Due to both wave and wind fluctuation, the metal foundations of offshore wind turbines are highly algorithm. KEYWORDS: Fatigue, Damage, Reliability, Bayesian updating. INTRODUCTION In offshore wind turbines

Boyer, Edmond

288

Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with  

E-Print Network [OSTI]

Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with Emphasis of offshore wind turbines Defense: 09.12.2012 2012 - : Structural Engineer in Det Norske Veritas (DNV) 2007 of the drive train of an on-land wind turbine under dynamic wind loads. The main tasks of this study are to

Nørvåg, Kjetil

289

Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women  

E-Print Network [OSTI]

The purpose of this study was to examine the effects of 5 days of Creatine (Cr) loading on the electromyographic fatigue threshold (EMGFT) in college-aged women. Fifteen healthy college-aged women (mean SD = 22.3 1.7 ...

Smith, Abbie E.; Walter, Ashley A.; Herda, Trent J.; Ryan, Eric D.; Moon, Jordan R.; Cramer, Joel T.; Stout, Jeffrey R.

2007-01-01T23:59:59.000Z

290

Influence of Impurity Segregation on Temper Embrittlement and on Slow Fatigue Crack  

E-Print Network [OSTI]

of segregated impurity atoms (temper embrittlement) and hydrogen atoms, evolved from crack tip surface reactions with water vapor in the moist air environment (hydrogen embrittlement). The signifi- cance of crack closureInfluence of Impurity Segregation on Temper Embrittlement and on Slow Fatigue Crack Growth

Ritchie, Robert

291

THERMAL FATIGUE AND FAILURE OF ELECTRONIC POWER DEVICE SUBSTRATES. S. Pietranico1&2  

E-Print Network [OSTI]

. For large thermal amplitudes, the failure occurs in DBC substrates, which are copper/ceramic in power modules, because of their good thermal conductivity. They are composed (Fig. 1) of a ceramic layer- 1 - THERMAL FATIGUE AND FAILURE OF ELECTRONIC POWER DEVICE SUBSTRATES. S. Pietranico1&2 , S

292

A systematic study of hcp crystal orientation and morphology effects in polycrystal deformation and fatigue  

Science Journals Connector (OSTI)

...components operating in gas turbines in both the aerospace...dwell on fatigue life in titanium alloys...hard grain sizes remaining significantly smaller...and 50mum, and all remaining grains of size 10mum...applications. J. Eng. Gas Turb. Power. 125...

2007-01-01T23:59:59.000Z

293

TRANSIENT FATIGUE-CRACK GROWTH BEHAVIOR FOLLOWING VARIABLE-AMPLITUDE LOADING IN A  

E-Print Network [OSTI]

TRANSIENT FATIGUE-CRACK GROWTH BEHAVIOR FOLLOWING VARIABLE-AMPLITUDE LOADING IN A MONOLITHIC-crack growth behavior following variable-amplitude loading sequences has been investigated in a hot-toughened ceramics [13] following various variable-amplitude loading sequences. Transient retardations, involving

Ritchie, Robert

294

Bond and low cycle fatigue behavior of thermoset composite reinforcing for the concrete industry  

SciTech Connect (OSTI)

This thesis encompasses two separate research projects. The first project, described in Chapter 2 was a project investigating the fatigue behavior of thermoset Fiber Composite (FC) sandwich wall ties. The second research project detailed in this thesis was a project studying the bond and tensile properties of FC rod and FC fibers.

Barnes, B.

1990-09-21T23:59:59.000Z

295

FATIGUE BEHAVIOR OF PRESTRESSED CONCRETE BRIDGE1 GIRDERS STRENGTHENED WITH VARIOUS CFRP SYSTEMS2  

E-Print Network [OSTI]

1 FATIGUE BEHAVIOR OF PRESTRESSED CONCRETE BRIDGE1 GIRDERS STRENGTHENED WITH VARIOUS CFRP SYSTEMS2 Owen A. Rosenboom, Sami H. Rizkalla3 4 5 6 Synopsis:7 8 Carbon Fiber Reinforced Polymer (CFRP) materials provide a solution for the classical9 challenge facing bridge maintenance engineers: the upgrading

296

Delamination and Failure at Ply Drops in Carbon Fiber Laminates Under Static and Fatigue Loading  

E-Print Network [OSTI]

Delamination and Failure at Ply Drops in Carbon Fiber Laminates Under Static and Fatigue Loading in composites with thickness tapering has been a major concern in aerospace applications of carbon fibers, where carbon fiber and glass fiber prepreg laminates containing various ply drop geometries, and using thicker

297

Notch sensitivity of fatigue life in a Sylramic TM composite at elevated temperature  

E-Print Network [OSTI]

sensitivity; Fatigue; SiC composite; Embrittlement 1. Introduction Continuous-fiber ceramic composites (CFCCs in advanced gas turbine engines. The motivation for this activity is the desire to increase operating are expelled during unloading and the oxidizing atmosphere drawn into the composite through matrix cracks

Zok, Frank

298

Effect of in situ material properties on fatigue damage modes in titanium matrix composites  

SciTech Connect (OSTI)

Titanium matrix composites (TMC) and their behavior under mechanical fatigue loads was the subject of this research. The primary objective was to explain fatigue damage modes in center-notched TMC specimens. Two modes of damage have been observed in continuously reinforced, zero-degree unidirectional, SCS-6/Ti-15V-3Cr-3Al-3Sn (SCS-6/Ti-15-3) laminates. The fatigue specimens were destructively analyzed using optical microscopy to determine where cracks originated and how they grew throughout the specimen. A micromechanical model was developed to explain the fatigue crack patterns observed in the interface region surrounding the fibers of the woven and acrylic-binder TMC material systems. A two-dimensional (2-D) model of a longitudinal lamina with a center hole was used to obtain a set of displacement boundary conditions for an element near the notch, yet within the net section where the spiral crack patterns were observed. These boundary conditions were then used on a three-dimensional (3-D) unit cell model of the fiber, matrix, and interface.

Harmon, D. [Boeing Co., St. Louis, MO (United States); Jerina, K.L. [Washington Univ., St. Louis, MO (United States). Materials Science and Engineering Program

1999-02-01T23:59:59.000Z

299

2009 ASME WIND ENERGY SYMPOSIUM Static and Fatigue Testing of Thick Adhesive Joints for  

E-Print Network [OSTI]

1 2009 ASME WIND ENERGY SYMPOSIUM Static and Fatigue Testing of Thick Adhesive Joints for Wind as wind blade size has increased. Typical blade joints use paste adhesives several millimeters thick aircraft, which are also of relevance to wind blades in many instances. The strengths of lap-shear and many

300

A REVIEW AND EVALUATION OF EMERGING DRIVER FATIGUE DETECTION MEASURES AND TECHNOLOGIES  

E-Print Network [OSTI]

- 1 - A REVIEW AND EVALUATION OF EMERGING DRIVER FATIGUE DETECTION MEASURES AND TECHNOLOGIES Lawrence Barr1 , Heidi Howarth1 , Stephen Popkin1 , Robert J. Carroll2 1 John A. Volpe National times, rest periods, recovery opportunities, and response to customer needs can vary widely. In addition

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

DEATH BY SMALL FORCES: FAILURE BY FATIGUE IN WAVE-SWEPT MACROALGAE  

E-Print Network [OSTI]

on substratum type and location. Rocky shores in particular have served as model systems for ecological studies environment of rocky shores has been evaluated through structural, cellular, and molecular analyses mechanics and fatigue analysis, I found that cracks introduced into flat-bladed macroalgae grow in length

Denny, Mark

302

TEMPORAL INFORMATION OF LINEAR AND NONLINEAR LAMB WAVES FOR FATIGUE DAMAGE LOCALIZATION: ANALYSIS AND SYNTHESIS  

E-Print Network [OSTI]

TEMPORAL INFORMATION OF LINEAR AND NONLINEAR LAMB WAVES FOR FATIGUE DAMAGE LOCALIZATION: ANALYSIS AND SYNTHESIS Ming Hong1,2 , Zhongqing Su*1,3 , Ye Lu2 , Li Cheng1,3 1 Department of Mechanical Engineering widely applied to locate gross damage in plate structures, which may greatly facilitate the localization

Boyer, Edmond

303

Apparent activation energy of fused silica optical fibers in static fatigue in aqueous environments  

E-Print Network [OSTI]

to occur when ambient moisture reacts with the fiber surface causing subcritical crack growth.1?3 Fatigue of silica optical fiber is therefore controlled by the crack growth rate, c : , which depends for the crack growth, which was originally proposed by Charles and Hillig, based on simple chemical kinetics

Matthewson, M. John

304

J Am Cerom Soc 73 [4]893-903 (1990) Cyclic Fatigue-Crack Propagation in  

E-Print Network [OSTI]

InternationalScience Center, Thousand Oaks, California 91360 The subcritical growth of fatigue cracks under variable-amplitude cyclic loading, crack-growth rates show transient accelera- tions following low overloads, again analogous to behavior commonly observed in ductile metals. Cyclic crack-growth rates

Ritchie, Robert

305

EFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS  

E-Print Network [OSTI]

, toughness, creep, and subcritical crack growth [1± 10]. Under quasi-static loading, subcritical crack growthEFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS AT ELEVATED allow for consistent crack-growth monitoring in these materials at high temperatures, and even

Ritchie, Robert

306

Analysis of SNL/MSU/DOE fatigue database trends for wind turbine blade materials.  

SciTech Connect (OSTI)

This report presents an analysis of trends in fatigue results from the Montana State University program on the fatigue of composite materials for wind turbine blades for the period 2005-2009. Test data can be found in the SNL/MSU/DOE Fatigue of Composite Materials Database which is updated annually. This is the fifth report in this series, which summarizes progress of the overall program since its inception in 1989. The primary thrust of this program has been research and testing of a broad range of structural laminate materials of interest to blade structures. The report is focused on current types of infused and prepreg blade materials, either processed in-house or by industry partners. Trends in static and fatigue performance are analyzed for a range of materials, geometries and loading conditions. Materials include: sixteen resins of three general types, five epoxy based paste adhesives, fifteen reinforcing fabrics including three fiber types, three prepregs, many laminate lay-ups and process variations. Significant differences in static and fatigue performance and delamination resistance are quantified for particular materials and process conditions. When blades do fail, the likely cause is fatigue in the structural detail areas or at major flaws. The program is focused strongly on these issues in addition to standard laminates. Structural detail tests allow evaluation of various blade materials options in the context of more realistic representations of blade structure than do the standard test methods. Types of structural details addressed in this report include ply drops used in thickness tapering, and adhesive joints, each tested over a range of fatigue loading conditions. Ply drop studies were in two areas: (1) a combined experimental and finite element study of basic ply drop delamination parameters for glass and carbon prepreg laminates, and (2) the development of a complex structured resin-infused coupon including ply drops, for comparison studies of various resins, fabrics and pry drop thicknesses. Adhesive joint tests using typical blade adhesives included both generic testing of materials parameters using a notched-lap-shear test geometry developed in this study, and also a series of simulated blade web joint geometries fabricated by an industry partner.

Mandell, John F. (Montana State University, Bozeman, MT); Ashwill, Thomas D.; Wilson, Timothy J. (Montana State University, Bozeman, MT); Sears, Aaron T. (Montana State University, Bozeman, MT); Agastra, Pancasatya (Montana State University, Bozeman, MT); Laird, Daniel L.; Samborsky, Daniel D. (Montana State University, Bozeman, MT)

2010-12-01T23:59:59.000Z

307

Automatic generation and analysis of solar cell IV curves  

SciTech Connect (OSTI)

A photovoltaic system includes multiple strings of solar panels and a device presenting a DC load to the strings of solar panels. Output currents of the strings of solar panels may be sensed and provided to a computer that generates current-voltage (IV) curves of the strings of solar panels. Output voltages of the string of solar panels may be sensed at the string or at the device presenting the DC load. The DC load may be varied. Output currents of the strings of solar panels responsive to the variation of the DC load are sensed to generate IV curves of the strings of solar panels. IV curves may be compared and analyzed to evaluate performance of and detect problems with a string of solar panels.

Kraft, Steven M.; Jones, Jason C.

2014-06-03T23:59:59.000Z

308

Fatigue and Creep Crack Propagation behaviour of Alloy 617 in the Annealed and Aged Conditions  

SciTech Connect (OSTI)

The crack propagation behaviour of Alloy 617 was studied under various conditions. Elevated temperature fatigue and creep-fatigue crack growth experiments were conducted at 650 and 800 degrees C under constant stress intensity (triangle K) conditions and triangular or trapezoidal waveforms at various frequencies on as-received, aged, and carburized material. Environmental conditions included both laboratory air and characteristic VHTR impure helium. As-received Alloy 617 displayed an increase in the crack growth rate (da/dN) as the frequency was decreased in air which indicated a time-dependent contribution component in fatigue crack propagation. Material aged at 650C did not display any influence on the fatigue crack growth rates nor the increasing trend of crack growth rate with decreasing frequency even though significant microstructural evolution, including y (Ni3Al) after short times, occurred during aging. In contrast, carburized Alloy 617 showed an increase in crack growth rates at all frequencies tested compared to the material in the standard annealed condition. Crack growth studies under quasi-constant K (i.e. creep) conditions were also completed at 650 degrees C and a stress intensity of K = 40 MPa9 (square root)m. The results indicate that crack growth is primarily intergranular and increased creep crack growth rates exist in the impure helium environment when compared to the results in laboratory air. Furthermore, the propagation rates (da/dt) continually increased for the duration of the creep crack growth either due to material aging or evolution of a crack tip creep zone. Finally, fatigue crack propagation tests at 800 degrees C on annealed Alloy 617 indicated that crack propagation rates were higher in air than impure helium at the largest frequencies and lowest stress intensities. The rates in helium, however, eventually surpass the rates in air as the frequency is reduced and the stress intensity is decreased which was not observed at 650 degrees C.

Julian K. Benz; Richard N. Wright

2013-10-01T23:59:59.000Z

309

Waste heat recovery steam curves with unfired HRSGs  

SciTech Connect (OSTI)

A compilation of waste heat recovery steam curves for a sampling of gas turbines ranging in output from around 1 MW to more than 200 MW is presented. The gas turbine output data shown with each set of curves differs from the values given in the Performance Specifications section of the Handbook. That's because the values have been calculated to reflect the effects of a 4 inch inlet and 10 inch outlet pressure drop on power output (lower), heat rate (higher), mass flow (higher), and exhaust temperature (higher).

Not Available

1993-01-01T23:59:59.000Z

310

Renormalization of gauge theories in curved space-time  

SciTech Connect (OSTI)

We consider the renormalization of general gauge theories on curved space-time background, with the main assumption being the existence of a gauge-invariant and diffeomorphism invariant regularization. Using the Batalin-Vilkovisky formalism, one can show that the theory possesses gauge invariant and diffeomorphism invariant renormalizability at quantum level, up to an arbitrary order of the loop expansion. Starting from this point, we discuss the locality of the counterterms and the general prescription for constructing the power-counting renormalizable theories on curved background.

Lavrov, Peter M. [Department of Mathematical Analysis, Tomsk State Pedagogical University, 634061, Kievskaya St. 60, Tomsk (Russian Federation); Shapiro, Ilya L. [Departamento de Fisica, ICE, Universidade Federal de Juiz de Fora, Juiz de Fora, CEP: 36036-330, MG (Brazil)

2010-02-15T23:59:59.000Z

311

Revisiting galactic rotation curves given a noncommutative-geometry background  

E-Print Network [OSTI]

It was shown earlier by Rahaman et al. that a noncommutative-geometry background can account for galactic rotation curves without the need for dark matter. The smearing effect that characterizes noncommutative geometry is described by means of a Gaussian distribution intended to replace the Dirac delta function. The purpose of this paper is two-fold: (1) to account for the galactic rotation curves in a more transparent and intuitively more appealing way by replacing the Gaussian function by the simpler Lorentzian distribution proposed by Nozari and Mehdipour and (2) to show that the smearing effect is both a necessary and sufficient condition for meeting the stability criterion.

Kuhfittig, Peter K F

2014-01-01T23:59:59.000Z

312

Egypt-US commodity trade and the J-curve  

Science Journals Connector (OSTI)

Almost 73% of trade between Egypt and the USA involves the 36 industries for which continuous quarterly data are available over the period 1994I to 2007IV. We take advantage of this rich data set and test the J-curve hypothesis for each of the 36 industries. By relying upon a new definition of the J-curve, i.e., short-run deterioration combined with the long-run improvement of the trade balance subsequent to currency depreciation, we find evidence in support of the new definition in 16 industries. Previous research that used aggregate trade data could not support the phenomenon.

Mohsen Bahmani-Oskooee; Amr Sadek Hosny

2013-01-01T23:59:59.000Z

313

Design operators  

E-Print Network [OSTI]

Design operators is a thesis that investigates the nature and characteristics of the design process by examining the interaction of computation with architectural design. The effects of the introduction of these media in ...

Dritsas, Stylianos, 1978-

2004-01-01T23:59:59.000Z

314

A Comparison of Vehicle Speed at Day and Night Rural Horizontal Curves  

E-Print Network [OSTI]

This thesis documents the linear mixed model developed for vehicle speed along two-lane two-way rural horizontal curves in the outside lane. Speed data at each curve was collected at four points along the curve including the midpoint of the curve...

Quaium, Ridwan B.

2010-07-14T23:59:59.000Z

315

Analysis of Marine Diesel Fuel with the Advanced Distillation Curve Method  

Science Journals Connector (OSTI)

Analysis of Marine Diesel Fuel with the Advanced Distillation Curve Method ... Energy Fuels, 2013, 27 (2), ...

Peter Y. Hsieh; Kathryn R. Abel; Thomas J. Bruno

2013-01-17T23:59:59.000Z

316

Regulatory Design for RES-E Support Mechanisms: Learning Curves, Market Structure, and Burden-Sharing  

E-Print Network [OSTI]

Drawing from relevant experiences in power systems around the world, this paper offers a critical review of existing policy support mechanisms for RES-E (renewable energy sources for electricity), with a detailed analysis ...

Batlle, Carlos

317

Evaluation of design and operating speeds for crest vertical curves with limited sight distance  

E-Print Network [OSTI]

The Puerto Colon field is located in the Putumayo basin in southern Colombia, South America, and is operated by Empresa Colombiana de petroleos (ECOPETROL), which is the national oil company. The field produces from the Cretaceous sandstones...

Russell, Charles William

1994-01-01T23:59:59.000Z

318

Ranks of Elliptic Curves with Prescribed Torsion over Number Fields  

Science Journals Connector (OSTI)

......31], and compute Four of the points are cusps. The other four correspond to the pairs...six rational cusps, four cusps with field of...elliptic curve, P 2 a point of order 2, and P 9...2. Clearly, i is a lift of w 2. We denote the......

Johan Bosman; Peter Bruin; Andrej Dujella; Filip Najman

2014-01-01T23:59:59.000Z

319

The Orbifold Cohomology of Moduli of Hyperelliptic Curves  

Science Journals Connector (OSTI)

......bijection on the set of reduced points of D. We can thus use...of the genus 0 curve can lift to an automorphism of order...the number of Weierstrass points, and N=ord(alpha red...to zero, then there are four points in C whose image in C......

Nicola Pagani

2012-01-01T23:59:59.000Z

320

Evolutionary-algorithm-based analysis of gravitational microlensing light curves  

Science Journals Connector (OSTI)

......results of Vermaak ( , ); they cover most of the lensing zone, and...fitting binary light curves Given a set of parameters, obtaining the...priors that avoid hard limits - to cover cases where the secondary lens...the general algorithm otherwise set-up in much the same way as......

V. Rajpaul

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Existence and stability of curved multidimensional detonation fronts  

E-Print Network [OSTI]

Existence and stability of curved multidimensional detonation fronts N. Costanzino , H. K. Jenssen for ZND detonations was begun by J.J. Erpenbeck in [E1]. He used a normal mode analysis to define, multidimensional detonation fronts for ideal polytropic gases in both the ZND and Chapman-Jouguet models

Williams, Mark

322

Experience Curves and Solar PV Fred Heutte, Senior Policy Associate  

E-Print Network [OSTI]

of evidence suggests staying with the consensus experience curve estimate ­ a Learning Rate of 20% for solar Market Penetration and Cost Numerous approaches have been tried over time to project changes in market penetration, price and time for technology-oriented products (Junginger 2006). Among them are: · cost per

323

Why subduction zones are curved L. Mahadevan,1  

E-Print Network [OSTI]

. By considering a soft, thin, curved litho- spheric cap with either elastic or viscous rheology sup- ported the shape of arcuate of subduction zones and the bending strip of the dimple on a partly inverted thin but finite thickness (rather than either a complete spherical shell or a flat plate); (2) the shell thickness

Liang, Haiyi

324

Sequential Document Representations and Simplicial Curves Guy Lebanon  

E-Print Network [OSTI]

Sequential Document Representations and Simplicial Curves Guy Lebanon Department of Statistics The popular bag of words assumption repre- sents a document as a histogram of word oc- currences. While to robustly model long rage sequential trends in the document. We discuss the rep- resentation and its

Lebanon, Guy

325

Radiation by Moving Mirrors in Curved Space-Time  

Science Journals Connector (OSTI)

......theory in the presence of a mirror in a curved two-dimensional...change of acceleration of the mirror is independent of the state...comoving flux emitted by a mirror lowered in a static gravitational...Theory in Two-Dimensional Schwarzschild-de Sitter Spacetime. II......

Adrian Ottewill; Shin Takagi

1988-01-01T23:59:59.000Z

326

Wind Energy Learning Curves for Reference in Expert Elicitations  

E-Print Network [OSTI]

Wind Energy Learning Curves for Reference in Expert Elicitations Sarah Mangels, Erin Baker. Abstract: This study presents future projections of wind energy capacity and cost based on historical data. The study will be used during wind- energy expert elicitations (formal interviews aimed to quantify

Mountziaris, T. J.

327

Revisiting a functional form for the Lorenz curve  

Science Journals Connector (OSTI)

In a recent paper Rohde (2009) proposes a new functional form for estimating the Lorenz curve. This paper demonstrates that the model proposed by Rohde is a reparameterization of the model proposed by Aggarwal (1984). New and important properties of the model are established.

Jos Mara Sarabia; Faustino Prieto; Mara Sarabia

2010-01-01T23:59:59.000Z

328

Improving fatigue strength by producing residual stresses on surface of parts of gas-turbine engines using processing treatments  

Science Journals Connector (OSTI)

The paper deals with a comparison of results of measuring residual stresses and with the study of their ... effect on the fatigue strength of parts of gas-turbine engines after finish treatments by grinding, poli...

M. G. Yakovlev

2014-07-01T23:59:59.000Z

329

Fatigue failure in thin-film polycrystalline silicon is due to subcritical cracking within the oxide layer  

E-Print Network [OSTI]

Fatigue failure in thin-film polycrystalline silicon is due to subcritical cracking within with stress-induced surface oxide thicken- ing and moisture-assisted subcritical cracking in the amor- phous

Ritchie, Robert

330

Application of a Multi-Objective Approach and Sequential Covering Algorithm to the Fatigue Segment Classification Problem  

Science Journals Connector (OSTI)

In this paper, a multi-objective rule discovery approach is introduced to address the problem related to fatigue data editing. A set of rules are introduced to simplify the...very low, low and high...are chosen f...

Z. M. Nopiah; M. H. Osman; S. Abdullah

2014-03-01T23:59:59.000Z

331

Tongue-placed tactile biofeedback suppresses the deleterious effects of muscle fatigue on joint position sense at the ankle  

E-Print Network [OSTI]

Whereas the acuity of the position sense at the ankle can be disturbed by muscle fatigue, it recently also has been shown to be improved, under normal ankle neuromuscular state, through the use of an artificial tongue-placed tactile biofeedback. The underlying principle of this biofeedback consisted of supplying individuals with supplementary information about the position of their matching ankle position relative to their reference ankle position through electrotactile stimulation of the tongue. Within this context, the purpose of the present experiment was to investigate whether this biofeedback could mitigate the deleterious effect of muscle fatigue on joint position sense at the ankle. To address this objective, sixteen young healthy university students were asked to perform an active ankle-matching task in two conditions of No-fatigue and Fatigue of the ankle muscles and two conditions of No-biofeedback and Biofeedback. Measures of the overall accuracy and the variability of the positioning were determin...

Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

2007-01-01T23:59:59.000Z

332

The Thermal Fatigue Life Prediction of Diesel Engine Heating Components by the Strain-Range Partitioning Method  

Science Journals Connector (OSTI)

In this paper, first the loading condition of thermal load of marine diesel engine is analyzed, and then the stress-strain ... carried on the thermal fatigue life prediction of diesel engine heating components by...

Senior Engineer Gu Zetong; Hu Gan

1987-01-01T23:59:59.000Z

333

Contributions to an Improved Oxygen and Thermal Transport Model and Development of Fatigue Analysis Software for Asphalt Pavements  

E-Print Network [OSTI]

-rate binder oxidation and hardening kinetics and calibrated mechanistic approach with surface energy (CMSE) fatigue analysis algorithm from literature. Input data include reaction kinetics parameters, mixture test results, and pavement temperature. Carbonyl...

Jin, Xin

2012-02-14T23:59:59.000Z

334

Fatigue resistance of hot-mix asphalt concrete (HMAC) mixtures using the calibrated mechanistic with surface energy (CMSE) measurements approach  

E-Print Network [OSTI]

Fatigue cracking is one of the fundamental distresses that occur in the life of a Hot Mix Asphalt Concrete (HMAC) pavement. This load induced distress leads to structural collapse of the entire pavement ultimately and can only be remedied...

Ofori-Abebresse, Edward Kwame

2006-10-30T23:59:59.000Z

335

High temperature low-cycle fatigue of friction welded joints - type 304-304 stainless steel and alloy 718-718 nickel base superalloy  

SciTech Connect (OSTI)

This paper assesses the high-temperature low-cycle fatigue of the Type 304 stainless steel and Alloy 718 superalloy friction-welded joints. Strain controlled low-cycle fatigue tests for 304-304 and 718-718 friction-welded specimens were carried out at 923 K in air to obtain the fatigue strength of the joints. These materials were selected as the cyclic hardening and softening materials, respectively. The 304-304 welded specimens showed inferior fatigue strength in comparison with the base metal while the 718-718 specimens exhibited fatigue strength equivalent to that of the base metal. The difference in the fatigue strength between the two materials is discussed from the viewpoint of the cyclic deformation behavior and strain reduction at weld interface.

Wakai, T. (Power Reactor and Nuclear Fuel Development Corp., Ibaraki (Japan). Oarai Engineering Center); Sakane, M.; Ohnami, M. (Ritsumeikan Univ., Kyoto (Japan). Dept. of Mechanical Engineering); Okita, K. (Hyogo Prefectural Inst. of Industrial Research, Miki (Japan). Technical Center for Machinery and Metals); Fukuchi, Y. (Hyogo Prefectural Inst. of Industrial Research, Kobe (Japan))

1993-01-01T23:59:59.000Z

336

Implementation of a Biaxial Resonant Fatigue Test Method on a Large Wind Turbine Blade  

SciTech Connect (OSTI)

A biaxial resonant test method was utilized to simultaneously fatigue test a wind turbine blade in the flap and edge (lead-lag) direction. Biaxial resonant blade fatigue testing is an accelerated life test method utilizing oscillating masses on the blade; each mass is independently oscillated at the respective flap and edge blade resonant frequency. The flap and edge resonant frequency were not controlled, nor were they constant for this demonstrated test method. This biaxial resonant test method presented surmountable challenges in test setup simulation, control and data processing. Biaxial resonant testing has the potential to complete test projects faster than single-axis testing. The load modulation during a biaxial resonant test may necessitate periodic load application above targets or higher applied test cycles.

Snowberg, D.; Dana, S.; Hughes, S.; Berling, P.

2014-09-01T23:59:59.000Z

337

Microstructurally based thermomechanical fatigue lifetime model of solder joints for electronic applications  

SciTech Connect (OSTI)

We present a new methodology for predicting the fatigue life of solder joints for electronics applications. This approach involves integration of experimental and computational techniques. The first stage involves correlating the manufacturing and processing parameters with the starting microstructure of the solder joint. The second stage involves a series of experiments that characterize the evolution of the microstructure during thermal cycling. The third stage consists of a computer modeling and simulation effort that utilizes the starting microstructure and experimental data to produce a reliability prediction of the solder joint. This approach is an improvement over current methodologies because it incorporates the microstructure and properties of the solder directly into the model and allows these properties to evolve as the microstructure changes during fatigue.

Frear, D.R.; Rashid, M.M.; Burchett, S.N.

1993-07-01T23:59:59.000Z

338

Approach to the fatigue analysis of vertical-axis wind-turbine blades  

SciTech Connect (OSTI)

A cursory analysis of the stress history of wind turbine blades indicates that a single stress level at each wind speed does not adequately describe the blade stress history. A statistical description is required. Blade stress data collected from the DOE/ALCOA Low Cost experimental turbines indicate that the Rayleigh probability density function adequately describes the distribution of vibratory stresses at each wind speed. The Rayleigh probability density function allows the distribution of vibratory stresses to be described by the RMS of the stress vs. time signal. With the RMS stress level described for all wind speeds, the complete stress history of the turbine blades is known. Miner's linear cumulative damage rule is used as a basis for summing the fatigue damage over all operating conditions. An analytical expression is derived to predict blade fatigue life.

Veers, P.S.

1981-09-01T23:59:59.000Z

339

Rolling contact fatigue in martensitic 100Cr6: Subsurface hardening and crack formation  

E-Print Network [OSTI]

, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS bDepartment of Lubrication and Metallic Materials, SKF Engineering and Research Centre, Kelvinbaan 16, 3439 MT Nieuwegein, The Netherlands. Abstract Rolling contact fatigue tests on 100Cr6... ground to the deformed region. The unaffected area was cut into a thin plate with a rectangular section. The sectioned parts were cold- mounted, mechanically ground with silicon carbide papers, polished with 6 m, 1 m diamond suspensions, and final...

Kang, Jee-Hyun; Vegter, R. H.; Rivera-Daz-del-Castillo, Pedro E. J.

2014-04-13T23:59:59.000Z

340

Parametric calculations of fatigue-crack growth in piping. [PWR; BWR  

SciTech Connect (OSTI)

A major objective of this program is to provide data that can be used to formulate recommended revisions to ASME Section XI and regulatory requirements for inservice inspection of piping and pressure vessels. This study presents calculations of the growth of piping flaws produced by fatigue. Flaw growth was predicted as a function of the initial flaw size, the level and number of stress cycles, the piping material, and environmental factors.

Simonen, F.A.; Goodrich, C.W.

1983-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Tensile creep of soil-cement and its relationship to fatigue  

E-Print Network [OSTI]

mechanics to cement and concrete. He reported from the literature review that the presence of water appeared to enhance subcritical crack growth and confirmed it experimentally [34]. In addition, it was noted that the fracture surface energy (estimated...&t , due to the large elastic compliance. The creep data were then used to predict the fatigue life of soil-cement utilizing Schapery's crack growth theory in linear viscoelastic media. Paris' law was adopted to express both the predicteo (from...

Kim, Youngsoo

2012-06-07T23:59:59.000Z

342

A generalized fitting technique for the LIFE2 fatigue analysis code  

SciTech Connect (OSTI)

The analysis of component fatigue lifetime for a wind energy conversion system (WECS) requires that the component load spectrum be formulated in terms of stress cycles. Typically, these stress cycles are obtained from time series data using a cycle identification scheme. As discussed by many authors, the matrix or matrices of cycle counts that describe the stresses on a turbine are constructed from relatively short, representative samples of time series data. The ability to correctly represent the long-term behavior of the distribution of stress cycles from these representative samples is critical to the analysis of service lifetimes. Several techniques are currently used to convert representative samples to the lifetime cyclic loads on the turbine. There has been recently developed a set of fitting algorithms that is particularly useful for matching the body of the distribution of fatigue stress cycles on a turbine component. Fitting techniques are now incorporated into the LIFE2 fatigue/fracture analysis code for wind turbines. In this paper, the authors provide an overview of the fitting algorithms and describe the pre- and post-count algorithms developed to permit their use in the LIFE2 code. Typical case studies are used to illustrate the use of the technique.

Sutherland, H.J. [Sandia National Labs., Albuquerque, NM (United States). Wind Energy Research Dept.; Wilson, T. [Univ. of New Mexico, Albuquerque, NM (United States). New Mexico Engineering Research Inst.

1996-08-01T23:59:59.000Z

343

Monitoring Thermal Fatigue Damage In Nuclear Power Plant Materials Using Acoustic Emission  

SciTech Connect (OSTI)

Proactive aging management of nuclear power plant passive components requires technologies to enable monitoring and accurate quantification of material condition at early stages of degradation (i.e., pre-macrocrack). Acoustic emission (AE) is well-suited to continuous monitoring of component degradation and is proposed as a method to monitor degradation during accelerated thermal fatigue tests. A key consideration is the ability to separate degradation responses from external sources such as water spray induced during thermal fatigue testing. Water spray provides a significant background of acoustic signals, which can overwhelm AE signals caused by degradation. Analysis of AE signal frequency and energy is proposed in this work as a means for separating degradation signals from background sources. Encouraging results were obtained by applying both frequency and energy filters to preliminary data. The analysis of signals filtered using frequency and energy provides signatures exhibiting several characteristics that are consistent with degradation accumulation in materials. Future work is planned to enable verification of the efficacy of AE for thermal fatigue crack initiation detection. While the emphasis has been placed on the use of AE for crack initiation detection during accelerated aging tests, this work also has implications with respect to the use of AE as a primary tool for early degradation monitoring in nuclear power plant materials. The development of NDE tools for characterization of aging in materials can also benefit from the use of a technology such as AE which can continuously monitor and detect crack initiation during accelerated aging tests.

Meyer, Ryan M.; Ramuhalli, Pradeep; Watson, Bruce E.; Pitman, Stan G.; Roosendaal, Timothy J.; Bond, Leonard J.

2012-04-26T23:59:59.000Z

344

Effect of hydrogen on the fatigue behavior of alloy 600 at cathodic potential  

SciTech Connect (OSTI)

The purpose of this study is to investigate the fatigue crack growth behavior of mill annealed Alloy 600 in 0.1M NaCl solution at cathodic potential ({minus}1,300m V{sub SCE}) as a function of load frequency and load ratio (R = P{sub min}/P{sub max}), and to study the possible hydrogen-assisted cracking mechanism during fatigue testing. The hydrogen effects on Alloy 600 occur in air saturated NaCl solution at 25 C with specified load mode which differs from the operating conditions of PWR steam generators. The FCG tests in this study are for the basic research of fatigue behavior of Alloy 600 in aqueous environment. The enhancement of the FCG rates of Alloy 600 in 0.1M NaCl solution at 25 C and {minus}1,300m V{sub SCE} is due to hydrogen embrittlement, and the phenomenon is more significant as load frequency decreases and load ratio increases.

Ho, J.T.; Yu, G.P. [National Tsing-Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Nuclear Engineering] [National Tsing-Hua Univ., Hsinchu (Taiwan, Province of China). Dept. of Nuclear Engineering

1995-06-01T23:59:59.000Z

345

Motor System Energy Efficiency Supply Curves: A Methodology for Assessing  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Motor System Energy Efficiency Supply Curves: A Methodology for Assessing Motor System Energy Efficiency Supply Curves: A Methodology for Assessing the Energy Efficiency Potential of Industrial Motor Systems Speaker(s): Ali Hasanbeigi Date: February 8, 2011 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Aimee McKane Motor-driven equipment accounts for approximately 60% of manufacturing final electricity use worldwide. A major barrier to effective policymaking, and to more global acceptance of the energy efficiency potential in industrial motor systems, is the lack of a transparent methodology for quantifying the magnitude and cost-effectiveness of these energy savings. This paper presents the results of groundbreaking analyses conducted for five countries and one region to begin to address this barrier. Using a combination of expert opinion and available data from the United States,

346

McKinsey Carbon Supply Curves | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » McKinsey Carbon Supply Curves Jump to: navigation, search Tool Summary LAUNCH TOOL Name: McKinsey Carbon Supply Curves Agency/Company /Organization: McKinsey and Company Sector: Energy, Land Topics: GHG inventory, Resource assessment, Pathways analysis, Background analysis Website: www.mckinsey.com/clientservice/ccsi/ References: McKinsey Climate Change Special Initiative[1] "The transition to a low-carbon economy represents one of the key challenges facing leaders in the early 21st century. Our Climate Change Special Initiative is a cross-functional and cross-industry effort, which

347

Signal Attenuation Curve for Different Surface Detector Arrays  

E-Print Network [OSTI]

Modern cosmic ray experiments consisting of large array of particle detectors measure the signals of electromagnetic or muon components or their combination. The correction for an amount of atmosphere passed is applied to the surface detector signal before its conversion to the shower energy. Either Monte Carlo based approach assuming certain composition of primaries or indirect estimation using real data and assuming isotropy of arrival directions can be used. Toy surface arrays of different sensitivities to electromagnetic and muon components are assumed in MC simulations to study effects imposed on attenuation curves for varying composition or possible high energy anisotropy. The possible sensitivity of the attenuation curve to the mass composition is also tested for different array types focusing on a future apparatus that can separate muon and electromagnetic component signals.

Vicha, J; Nosek, D; Ebr, J

2014-01-01T23:59:59.000Z

348

THE LOS ALAMOS SUPERNOVA LIGHT-CURVE PROJECT: COMPUTATIONAL METHODS  

SciTech Connect (OSTI)

We have entered the era of explosive transient astronomy, in which current and upcoming real-time surveys such as the Large Synoptic Survey Telescope, the Palomar Transient Factory, and the Panoramic Survey Telescope and Rapid Response System will detect supernovae in unprecedented numbers. Future telescopes such as the James Webb Space Telescope may discover supernovae from the earliest stars in the universe and reveal their masses. The observational signatures of these astrophysical transients are the key to unveiling their central engines, the environments in which they occur, and to what precision they will pinpoint cosmic acceleration and the nature of dark energy. We present a new method for modeling supernova light curves and spectra with the radiation hydrodynamics code RAGE coupled with detailed monochromatic opacities in the SPECTRUM code. We include a suite of tests that demonstrate how the improved physics and opacities are indispensable to modeling shock breakout and light curves when radiation and matter are tightly coupled.

Frey, Lucille H. [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Even, Wesley; Hungerford, Aimee L. [XTD-6, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Whalen, Daniel J. [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fontes, Christopher J. [XCP-5, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Colgan, James [T-1, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-02-15T23:59:59.000Z

349

MAGNETIC FIELDS AND THE OUTER ROTATION CURVE OF M31  

SciTech Connect (OSTI)

Recent observations of the rotation curve of M31 show a rise of the outer part that cannot be understood in terms of standard dark matter models or perturbations of the galactic disk by M31's satellites. Here, we propose an explanation of this dynamical feature based on the influence of the magnetic field within the thin disk. We have considered standard mass models for the luminous mass distribution, a Navarro-Frenk-White model to describe the dark halo, and we have added up the contribution to the rotation curve of a magnetic field in the disk, which is described by an axisymmetric pattern. Our conclusion is that a significant improvement of the fit in the outer part is obtained when magnetic effects are considered. The best-fit solution requires an amplitude of {approx}4 {mu}G with a weak radial dependence between 10 and 38 kpc.

Ruiz-Granados, B.; Rubino-Martin, J. A. [Instituto de Astrofisica de Canarias (IAC), E-38200, La Laguna, Tenerife (Spain); Florido, E.; Battaner, E. [Departamento Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain)

2010-11-01T23:59:59.000Z

350

Driven Around the Bend: Novel Use of a Curved Steerable Needle  

SciTech Connect (OSTI)

This technical note describes the novel use of a curved, steerable needle to access symptomatic osseous lesions in the pelvis and sacrum for palliative percutaneous treatment that would otherwise be difficult to treat using conventional straight needles. Seven patients with lytic bone lesions were treated. One patient had multiple myeloma; the remaining had metastatic disease: breast carcinoma (n = 2), colorectal carcinoma (n = 1), renal cell carcinoma (n = 1), squamous cell carcinoma (n = 1), and leiomyosarcoma (n = 1). Five of the seven patients had lesions in the posterior acetabulum, and the two other patients had lesions in the sacrum. Four of the seven patients received radiofrequency ablation followed by cementoplasty; three patients received cementation alone. We used a novel needle designed for vertebroplasty, which has an articulating tip allowing it to be guided into lytic bone lesions located in difficult-to-access regions of the pelvis and sacrum. All patients were successfully treated with cementoplasty either with or without thermal ablation. No serious adverse events were reported. The needle was difficult to withdraw in two patients. Steerable curved needles can be successfully used to treat lytic osseous metastases with cementoplasty when lesions are located in sites that may be difficult to reach using conventional straight needles.

Murphy, Darra T., E-mail: darra.murphy@vch.ca; Korzan, Jeffrey R.; Ouellette, Hugue A.; Liu, David M. [Vancouver General Hospital, Department of Radiology (Canada)] [Vancouver General Hospital, Department of Radiology (Canada); Clarkson, Paul W. [Vancouver General Hospital, Department of Orthopedic Surgery (Canada)] [Vancouver General Hospital, Department of Orthopedic Surgery (Canada); Munk, Peter L. [Vancouver General Hospital, Department of Radiology (Canada)] [Vancouver General Hospital, Department of Radiology (Canada)

2013-04-15T23:59:59.000Z

351

Graphene based tunable fractal Hilbert curve array broadband radar absorbing screen for radar cross section reduction  

SciTech Connect (OSTI)

This paper proposes a new type of graphene based tunable radar absorbing screen. The absorbing screen consists of Hilbert curve metal strip array and chemical vapour deposition (CVD) graphene sheet. The graphene based screen is not only tunable when the chemical potential of the graphene changes, but also has broadband effective absorption. The absorption bandwidth is from 8.9GHz to 18.1GHz, ie., relative bandwidth of more than 68%, at chemical potential of 0eV, which is significantly wider than that if the graphene sheet had not been employed. As the chemical potential varies from 0 to 0.4eV, the central frequency of the screen can be tuned from 13.5GHz to 19.0GHz. In the proposed structure, Hilbert curve metal strip array was designed to provide multiple narrow band resonances, whereas the graphene sheet directly underneath the metal strip array provides tunability and averagely required surface resistance so to significantly extend the screen operation bandwidth by providing broadband impedance matching and absorption. In addition, the thickness of the screen has been optimized to achieve nearly the minimum thickness limitation for a nonmagnetic absorber. The working principle of this absorbing screen is studied in details, and performance under various incident angles is presented. This work extends applications of graphene into tunable microwave radar cross section (RCS) reduction applications.

Huang, Xianjun, E-mail: xianjun.huang@manchester.ac.uk [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Hu, Zhirun [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Liu, Peiguo [College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-11-15T23:59:59.000Z

352

An improved method to predict future IPR curves  

SciTech Connect (OSTI)

This paper presents a significantly improved yet simple method to predict future oilwell deliverability and inflow performance relationship (IPR) curves. For the 21 reservoirs studied, current empirical techniques overpredicted future performance by 117%, while the new approach reduced the average error to only 9%. This new method, when coupled with nodal analysis, could affect equipment sizing, investment planning, and property sales economics significantly because it provides more realistic predictions.

Klins, M.A. (Chevron U.S.A. Production Co., Inc., Lost Hills, CA (United States)); Clark, J.W. III (Chevron Petroleum Technology Co., Inc., La Habra, CA (United States))

1993-11-01T23:59:59.000Z

353

Optimal reliability-based planning of experiments for POD curves  

SciTech Connect (OSTI)

Optimal planning of crack detection tests is considered. The tests are used to update the information on the reliability of inspection techniques modeled by probability of detection (P.O.D.) curves. It is shown how cost-optimal and reliability-based test plans can be obtained using First Order Reliability Methods in combination with life-cycle cost-optimal inspection and maintenance planning. The methodology is based on preposterior analyses from Bayesian decisions theory. An illustrative example is shown.

Soerensen, J.D. [Univ. of Aalborg (Denmark). Dept. of Building Technology and Structural Engineering; Faber, M.H.; Kroon, I.B. [COWIconsult Consulting Engineers and Planners AS, Lyngby (Denmark). Transportation Div.

1995-12-31T23:59:59.000Z

354

Application of the decline curve method to aquifers  

E-Print Network [OSTI]

curves for Fetkovich aquifers. . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . 22 23 24 11a. Semi-log straight line behavior for an aquifer in pseudosteady state. . . . . . . . . . 24 1 lb, Comparison between the normalized influx rate... early for a strong water drive and later for a weak aquifer support. This fact is concluded by Bruns and Fetkovich3 where the authors studied the effect of water influx on p/z plot and showed that shape depends not only on the strength of the aquifer...

Potnis, Girish Vijay

1992-01-01T23:59:59.000Z

355

Optical and EUV light curves of dwarf nova outbursts  

SciTech Connect (OSTI)

We combine AAVSO and VSS/RASNZ optical and Extreme Ultraviolet Explorer EUV light curves of dwarf novae in outburst to place constraints on the nature of dwarf nova outbursts. From the observed optical-EUV time delays of {approx} 0.75-1.5 days, we show that the propagation velocity of the dwarf nova instability heating wave is {approx} 3 km s{sup -1}.

Mauche, C W; Mattei, J A; Bateson, F M

2000-11-15T23:59:59.000Z

356

A consideration of a micro-Phillips' Curve  

E-Print Network [OSTI]

-Phillips' Curves using an SMSA as the definition of a labor market. Sixteen SMSA's were separately studied by regressing wage changes on the unemployment rate and the rate of change of unemploy- ment for monthly data. The sixteen SMSA's were then pooled via a... covariance model to form a national labor market. iv It was found that the estimated regression coefficient for the unemployment rate was insignificant at the . 10 level of significance on both the aggregate and disaggregate level. This suggests...

Paczkowski, Walter Richard

2012-06-07T23:59:59.000Z

357

Composition-Explicit Distillation Curves of Alternative Turbine Fuels  

Science Journals Connector (OSTI)

National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, Colorado 80305, United States ... In recent years, environmental considerations, the potential for supply disruptions, and rising fuel prices have led to the development of turbine fuels produced from non-petroleum feedstocks. ... We found that the distillation curves of the chicken-fat-derived fuel and the gasliquid turbine fuel were similar to those of JP-8, deviating the most at high distillate volume fractions. ...

R. V. Gough; T. J. Bruno

2012-12-03T23:59:59.000Z

358

Evaluate the fracture and fatigue resistances of hot mix asphalt containing high percentage reclaimed asphalt pavement (RAP) materials at low and intermediate temperatures.  

E-Print Network [OSTI]

??When applying recycled asphalt technology in a flexible pavement project, most of the concerns are related to low-temperature fracture and fatigue cracking, since the stiffness (more)

Tang, Sheng

2014-01-01T23:59:59.000Z

359

PREDICTION OF LOW-CYCLE FATIGUE-LIFE BY ACOUSTIC EMISSION. PART 1: 2024-T3 ALUMINUM ALLOY PART 2: ALCLAD 7075-T6/ ALUMINUM ALLOY  

E-Print Network [OSTI]

low-cycle fatigue life of Aluminum sheet alloys by acoustictoughness of structural aluminum alloys. Fracture . Fracturetoughness of structural aluminum alloys, Eng. Fracture Mech.

Baram, J.

2013-01-01T23:59:59.000Z

360

A reaction-layer mechanism for the delayed failure of micron-scale polycrystalline silicon structural films subjected to high-cycle fatigue loading  

SciTech Connect (OSTI)

A study has been made of high-cycle fatigue in 2um thick structural films of n+- type, polycrystalline silicon for MEMS applications.

Muhlstein, C.L.; Stach, E.A.; Ritchie, R.O.

2001-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Motor Systems Efficiency Supply Curves | Open Energy Information  

Open Energy Info (EERE)

Motor Systems Efficiency Supply Curves Motor Systems Efficiency Supply Curves Jump to: navigation, search Tool Summary Name: Motor Systems Efficiency Supply Curves Agency/Company /Organization: United Nations Industrial Development Organization Sector: Energy Focus Area: Energy Efficiency, Industry Topics: Technology characterizations Resource Type: Publications, Case studies/examples Website: www.unido.org/fileadmin/user_media/Services/Energy_and_Climate_Change/ Country: United States, Canada, Thailand, Vietnam, Brazil UN Region: South-Eastern Asia, "Latin America and Caribbean" is not in the list of possible values (Eastern Africa, Middle Africa, Northern Africa, Southern Africa, Western Africa, Caribbean, Central America, South America, Northern America, Central Asia, Eastern Asia, Southern Asia, South-Eastern Asia, Western Asia, Eastern Europe, Northern Europe, Southern Europe, Western Europe, Australia and New Zealand, Melanesia, Micronesia, Polynesia, Latin America and the Caribbean) for this property., Northern America, "Western & Eastern Europe" is not in the list of possible values (Eastern Africa, Middle Africa, Northern Africa, Southern Africa, Western Africa, Caribbean, Central America, South America, Northern America, Central Asia, Eastern Asia, Southern Asia, South-Eastern Asia, Western Asia, Eastern Europe, Northern Europe, Southern Europe, Western Europe, Australia and New Zealand, Melanesia, Micronesia, Polynesia, Latin America and the Caribbean) for this property.

362

Indonesia Greenhouse Gas Abatement Cost Curve | Open Energy Information  

Open Energy Info (EERE)

Indonesia Greenhouse Gas Abatement Cost Curve Indonesia Greenhouse Gas Abatement Cost Curve Jump to: navigation, search Tool Summary Name: Indonesia Greenhouse Gas Abatement Cost Curve Agency/Company /Organization: Government of Indonesia Topics: Baseline projection, GHG inventory, Co-benefits assessment, Background analysis Resource Type: Software/modeling tools Website: www.dnpi.go.id/report/DNPI-Media-Kit/reports/indonesia-ghg_abatement_c Country: Indonesia UN Region: South-Eastern Asia Coordinates: -0.789275°, 113.921327° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":-0.789275,"lon":113.921327,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

363

Method of non-destructively inspecting a curved wall portion  

DOE Patents [OSTI]

A method of non-destructively inspecting a curved wall portion of a large and thick walled vessel for a defect by computed tomography is provided. A collimated source of radiation is placed adjacent one side of the wall portion and an array of detectors for the radiation is placed on the other side adjacent the source. The radiation from the source passing through the wall portion is then detected with the detectors over a limited angle, dependent upon the curvature of the wall of the vessel, to obtain a dataset. The source and array are then coordinately moved relative to the wall portion in steps and a further dataset is obtained at each step. The plurality of datasets obtained over the limited angle is then processed to produce a tomogram of the wall portion to determine the presence of a defect therein. In a preferred embodiment, the curved wall portion has a center of curvature so that the source and the array are positioned at each step along a respective arc curved about the center. If desired, the detector array and source can be reoriented relative to a new wall portion and an inspection of the new wall portion can be easily obtained. Further, the source and detector array can be indexed in a direction perpendicular to a plane including the limited angle in a plurality of steps so that by repeating the detecting and moving steps at each index step, a three dimensional image can be created of the wall portion.

Fong, James T. (Bethel Park, PA)

1996-01-01T23:59:59.000Z

364

Elevated Temperature Materials for Power Generation and Propulsion The energy industry is designing higher-efficiency land-based turbines for natural gas-fired  

E-Print Network [OSTI]

higher-efficiency land-based turbines for natural gas-fired power generation systems. The high inletElevated Temperature Materials for Power Generation and Propulsion The energy industry is designing of thermomechanical fatigue life of the next generation's Ni-base superalloys are being developed to enhance life

Li, Mo

365

Design Competitions  

Broader source: Energy.gov [DOE]

National design competitions heighten awareness and market adoption of high-performance solid-state lighting products.

366

DESIGN OF INTELLIGENT HYDRAULIC EXCAVATOR CONTROL SYSTEM BASED ON  

E-Print Network [OSTI]

according to the engine consumption fuel curve. Transient overload function was designed for deep digging that the auto idle could decrease fuel consumption by 33.33% compared to work in maximum speed of H mode the constant power design method and set 85%~90% of engine power as the hydraulic system adoption power

367

Using growth curves to forecast regional resource recovery: approaches, analytics and consistency tests  

Science Journals Connector (OSTI)

...ultimately recoverable resources|peak oil|logistic model|growth curves...6 Mohr, S , and G Evans. 2008 Peak oil: testing Hubberts curve via theoretical...28 Mohr, SH , and GM Evans. 2008 Peak oil: testing Hubberts methodology via...

2014-01-01T23:59:59.000Z

368

Characterization of a pre-curved stylet distal tip manipulation mechanism for use in volume targeting  

E-Print Network [OSTI]

The characterization of the volume targeting capabilities of a telerobotic device capable of needle distal tip manipulation with a pre-curved needle is the focus of this thesis. The concept of deploying a pre-curved stylet ...

Ding, Hao, S.B. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

369

Exploiting Domain Knowledge for Improved Quantitative High-Throughput Screening Curve Fitting  

Science Journals Connector (OSTI)

One popular measure of curve-fitting (or regression) performance obtained from the REC curve is its area over the curve (AOC):The AOC is the area between a curve and the horizontal line at unit accuracy; a smaller AOC is desirable. ... The AOC is a reasonable estimate of the mean absolute error (MAE). ... This scatter plot compares the AOC (eq 10) for the LS- and DK-fitter techniques for all 43 qHTS screens considered in this study. ...

Charles Bergeron; Gregory Moore; Michael Krein; Curt M. Breneman; Kristin P. Bennett

2011-10-14T23:59:59.000Z

370

Small distance expansion for radiative heat transfer between curved objects  

E-Print Network [OSTI]

We develop a small distance expansion for the radiative heat transfer between gently curved objects, in terms of the ratio of distance to radius of curvature. A gradient expansion allows us to go beyond the lowest order proximity transfer approximation. The range of validity of such expansion depends on temperature as well as material properties. Generally, the expansion converges faster for the derivative of the transfer than for the transfer itself, which we use by introducing a near-field adjusted plot. For the case of a sphere and a plate, the logarithmic correction to the leading term has a very small prefactor for all materials investigated.

Vladyslav A. Golyk; Matthias Krger; Alexander P. McCauley; Mehran Kardar

2012-10-12T23:59:59.000Z

371

Analysis of pressure buildup curves based on field experience  

SciTech Connect (OSTI)

This paper deals with the application of pressure build-up data in computing vital reservoir parameters in oil fields. Generally the technique of Miller Dyes and Hutchinson is utilized to determine flow capacity, permeability skin effect and completion efficiency. Pressure build-up data is utilized in detecting the existence of faults. The method of Brons and Marting has been found to be more reliable to determine the partial penetration effect. The computer software package which was developed recently is discussed and, due to near ideal behaviour of pressure build-up curves, is safely utilized. The computational work using the software package is rapid.

Arora, P.D.

1983-03-01T23:59:59.000Z

372

The syntomic regulator for $K_4$ of curves.  

E-Print Network [OSTI]

Let $C$ be a curve defined over a discrete valuation field of characteristic zero where the residue field has positive characteristic. Assuming that $C$ has good reduction over the residue field, we compute the syntomic regulator on a certain part of $K_4^[(3)}(C)$. The result can be expressed in terms of $p$-adic polylogarithms and Coleman integration. We also compute the syntomic regulator on a certain part of $K_4^[(3)}(F)$ for the function field $F$ of $C$. The result can be expressed in terms of $p$-adic polylogarithms and Coleman integration, or by using a trilinear map ("triple index") on certain functions.

Amnon Besser; Rob de Jeu

373

Identification of New Keynesian Phillips Curves from a Global Perspective  

E-Print Network [OSTI]

S us,t - Long-Term Interest Rate rLit r ?L it r L us,t - Oil Price - pot pot - The GVAR model has 134 endogenous variables 71 stochastic trends and 63 cointegrating rela- tions. All its roots either lie on or inside the unit circle. The long run forcing... ), identification, New Keynesian Phillips Curve, Trend-Cycle decompo- sition. JEL Classification: C32, E17, F37, F42. ?For Stephane Dees, the views expressed in this paper do not necessarily reflect the views of the European Central Bank or the Eurosystem. The other...

Dees, S; Pesaran, M Hashem; Smith, L Vanessa; Smith, Ron P

374

Ris-R-Report Multi-MW wind turbine power curve  

E-Print Network [OSTI]

Risø-R-Report Multi-MW wind turbine power curve measurements using remote sensing instruments Wagner, Michael Courtney Title: Multi-MW wind turbine power curve measurements using remote sensing (max. 2000 char.): Power curve measurement for large wind turbines requires taking into account more

375

Green's Conjecture for curves on arbitrary K3 Marian Aprodu and Gavril Farkas  

E-Print Network [OSTI]

Green's Conjecture for curves on arbitrary K3 surfaces Marian Aprodu and Gavril Farkas Abstract Green's Conjecture predicts than one can read off special linear series on an algebraic curve-Ramanan, provides a complete solution to Green's Conjecture for smooth curves on arbitrary K3 surfaces. 1

Farkas, Gavril

376

THE GREEN CONJECTURE FOR EXCEPTIONAL CURVES ON A K3 SURFACE  

E-Print Network [OSTI]

THE GREEN CONJECTURE FOR EXCEPTIONAL CURVES ON A K3 SURFACE to prove the Green conjecture f* *or exceptional curves on K3 surfaces. Such curves count among made in the eighties by Green, and Green-Lazarsfeld, pointed * *out to some deep links between

Pacienza, Gianluca

377

An Appliance-driven Approach to Detection of Corrupted Load Curve Data  

E-Print Network [OSTI]

@sfu.ca, jiuyang_tang@nudt.edu.cn, jshlei@shiep.edu.cn ABSTRACT Load curve data in power systems refers to usersAn Appliance-driven Approach to Detection of Corrupted Load Curve Data Guoming Tang1,3 , Kui Wu1 discov- ered in the data. Load curve data, however, usually suffers from corruptions caused by various

Pei, Jian

378

Homogeneous studies of transiting extrasolar planets IV. Thirty systems with space-based light curves  

Science Journals Connector (OSTI)

......HAT-P-11 A in the Kepler light curve. This indicates a much...al. 2003). Further transit light curves were obtained by Gillon...et al. (2008). Two good light curves were presented by Winn...covering the transit on Christmas Day in 2007. The RM effect......

John Southworth

2011-11-01T23:59:59.000Z

379

Biomaterials 24 (2003) 52095221 Crack blunting, crack bridging and resistance-curve fracture  

E-Print Network [OSTI]

Biomaterials 24 (2003) 5209­5221 Crack blunting, crack bridging and resistance-curve fracture focused on a description of the fracture toughness properties of dentin in terms of resistance-curve (R-curve) behavior, i.e., fracture resistance increasing with crack extension, particularly in light of the relevant

Ritchie, Robert

380

On the Parameterization of Catmull-Rom Curves Texas A&M University  

E-Print Network [OSTI]

On the Parameterization of Catmull-Rom Curves Cem Yuksel Texas A&M University Scott Schaefer Texas A&M University John Keyser Texas A&M University ABSTRACT The behavior of Catmull-Rom curves. In this pa- per we prove that, for cubic Catmull-Rom curves, centripetal parameterization is the only

Keyser, John

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381

COMPLEX ORIENTANTION FORMULAS FOR M-CURVES OF DEGREE 4d + 1 WITH 4 NESTS  

E-Print Network [OSTI]

COMPLEX ORIENTANTION FORMULAS FOR M-CURVES OF DEGREE 4d + 1 WITH 4 NESTS S.Yu. Orevkov Abstract. We prove complex orientation formulas for M-curves in RP2 of degree 4d + 1 with 4 nests. They generalize the formulas of complex orientations for M- curves in RP2 with a deep nest. This is a step towards the isotopy

Orevkov, Stepan

382

Materials for Advanced Turbine Engines (MATE). Project 3: design, fabrication and evaluation of an oxide dispersion strengthened sheet alloy combustor liner. Final Report  

SciTech Connect (OSTI)

The suitability of wrought oxide dispersion strengthened (ODS) superalloy sheet for gas turbine engine combustor applications was evaluated. Incoloy MA 956 (FeCrAl base) and Haynes Developmental Alloy (HDA) 8077 (NiCrAl base) were evaluated. Preliminary tests showed both alloys to be potentially viable combustor materials, with neither alloy exhibiting a significant advantage over the other. Both alloys demonstrated a +167C (300 F) advantage of creep and oxidation resistance with no improvement in thermal fatigue capability compared to a current generation combustor alloy (Hastelloy X). MA956 alloy was selected for further demonstration because it exhibited better manufacturing reproducibility than HDA8077. Additional property tests were conducted on MA956. To accommodate the limited thermal fatigue capability of ODS alloys, two segmented, mechanically attached, low strain ODS combustor design concepts having predicted fatigue lives or 10,000 engine cycles were identified. One of these was a relatively conventional louvered geometry, while the other involved a transpiration cooled configuration. A series of 10,000 cycle combustor rig tests on subscale MA956 and Hastelloy X combustor components showed no cracking, thereby confirming the beneficial effect of the segmented design on thermal fatigue capability. These tests also confirmed the superior oxidation and thermal distortion resistance of the ODS alloy. A hybrid PW2037 inner burner liner containing MA956 and Hastelloy X components was designed and constructed.

Henricks, R.J.; Sheffler, K.D.

1984-02-01T23:59:59.000Z

383

Structural Safety and Reliability, Corotis et al. (eds), 2001 Swets & Zeitlinger, ISBN 90 5809 197 X Moment-based fatigue load models for wind energy systems  

E-Print Network [OSTI]

197 X 1 Moment-based fatigue load models for wind energy systems Steven R. Winterstein & LeRoy M. Veers Sandia National Laboratories, Wind Energy Technology Department, Albuquerque, NM 87185-0708 Keywords: load models, fatigue loads, wind energy, non-Gaussian, moment-based models, long- term, short

Manuel, Lance

384

Mixed-mode, high-cycle fatigue-crack growth thresholds in I. A comparison of large-and short-crack behavior  

E-Print Network [OSTI]

) in a Ti±6Al±4V turbine blade alloy with a bimodal microstructure. Speci®cally, the eect of combined mode I machined to within $200 lm of the precrack tip. For such short cracks, wherein the magnitude of crack, particularly in association with fretting fatigue in the blade dovetail/disk contact section [3]. For fatigue

Ritchie, Robert

385

FPGA-based hardware CNC interpolator of Bezier, splines, B-splines and NURBS curves for industrial applications  

Science Journals Connector (OSTI)

Abstract Tool path interpolation is an important part of Computerized Numerical Control (CNC) systems because it is related to the machining accuracy, tool-motion smoothness and overall efficiency. The use of parametric curves to generate tool-motion trajectories on a workpiece for high accuracy machining has become a standard data format that is used for CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) and CNC systems. Splines, Bezier, B-splines, and NURBS (Non-Uniform Rational B-splines) curves are the common parametric technique used for tool path design. However, the reported works bring out the high computational load required for this type of interpolation, and then at best only one interpolation algorithm is implemented. The contribution of this paper is the development of a hardware processing unit based on Field Programmable Gate Arrays (FPGA) for industrial CNC machines, which is capable of implementing the four main interpolation techniques. It allows the selection of the required interpolation technique according the application. Two CAD models are designed for test the CNC interpolations; experimental results show the efficiency of the proposed methodology.

J.J. De Santiago-Perez; R.A. Osornio-Rios; R.J. Romero-Troncoso; L. Morales-Velazquez

2013-01-01T23:59:59.000Z

386

Influence of temperature, environment, and thermal aging on the continuous cycle fatigue behavior of Hastelloy X and Inconel 617  

SciTech Connect (OSTI)

Results are presented for strain-controlled fatigue and tensile tests for two nickel-base, solution-hardened reference structural alloys for use in several High-Temperature Gas-Cooled Reactor (HTGR) concepts. These alloys, Hastelloy X and Inconel 617, were tested from room temperature to 871/sup 0/C in air and impure helium. Materials were tested in both the solution-annealed and the preaged conditios, in which aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are given between the strain-controlled fatigue lives of these and several other commonly used alloys, all tested at 538/sup 0/C. An analysis is also presented of the continuous cycle fatigue data obtained from room temperature to 427/sup 0/C for Hastelloy G, Hastelloy X, Hastelloy C-276, and Hastelloy C-4, an effort undertaken in support of ASME code development.

Strizak, J.P.; Brinkman, C.R.; Booker, M.K.; Rittenhouse, P.L.

1982-04-01T23:59:59.000Z

387

Galaxy rotation curves from general relativity with renormalization group corrections  

SciTech Connect (OSTI)

We consider the application of quantum corrections computed using renormalization group arguments in the astrophysical domain and show that, for the most natural interpretation of the renormalization group scale parameter, a gravitational coupling parameter G varying 10{sup ?7} of its value across a galaxy (which is roughly a variation of 10{sup ?12} per light-year) is sufficient to generate galaxy rotation curves in agreement with the observations. The quality of the resulting fit is similar to the Isothermal profile quality once both the shape of the rotation curve and the mass-to-light ratios are considered for evaluation. In order to perform the analysis, we use recent high quality data from nine regular disk galaxies. For the sake of comparison, the same set of data is modeled also for the Modified Newtonian Dynamics (MOND) and for the recently proposed Scalar Tensor Vector Gravity (STVG). At face value, the model based on quantum corrections clearly leads to better fits than these two alternative theories.

Rodrigues, Davi C.; Letelier, Patricio S. [Departamento de Matemtica Aplicada, IMECC, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Shapiro, Ilya L., E-mail: davi@ime.unicamp.br, E-mail: letelier@ime.unicamp.br, E-mail: shapiro@fisica.ufjf.br [Departamento de Fsica, ICE, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG (Brazil)

2010-04-01T23:59:59.000Z

388

Logistic curves, extraction costs and effective peak oil  

Science Journals Connector (OSTI)

Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the use of logistic curves for cumulative production are supplemented with data on projected extraction costs and historical rates of capacity increase. While not denying the presence of large quantities of oil in the ground, even with foresight, rates of production of new nonconventional resources are unlikely to be sufficient to make up for declines in availability of conventional oil. Furthermore we show how the logistic-curve approach helps to naturally explain high oil prices even when there are significant quantities of low-cost oil yet to be extracted.

Robert J. Brecha

2012-01-01T23:59:59.000Z

389

On the Nuclear Rotation Curve of M31  

E-Print Network [OSTI]

The nuclear rotation curve of M31, as observed by the Hubble Space Telescope Faint Object Camera Spectrograph, shows a significant disturbance coinciding with the off-center brightness peak, P1. This +/- 60 km/s feature is distinguished by a local velocity maximum centered on P1 and a local minimum approxmately 0.08" closer to P2. If the M31 double nucleus is an eccentric disk with an off-center density concentration, as suggested by Tremaine, then the self-gravity of the disk can produce just such a disturbance. The expected kinematic signature is calculated approximately by examining sequences of closed periodic orbits in a Kepler potential perturbed by a model disk potential that precesses at constant frequency. The perturbation forces a steep negative eccentricity gradient in the sequence of closed orbits through the densest part of the disk, which reverses the arrangement of periapsis and apoapsis with respect to the central mass. Stars making up the inner part of the density concentration are at apoapsis, while stars making up the outer part are at periapsis, producing a steep local velocity gradient. This result is independent of the details of the mass distribution. The projected rotation curve of the model is shown to closely resemble that of M31, giving strong support to the eccentric disk picture.

Thomas S. Statler

1999-05-08T23:59:59.000Z

390

Design Specifications  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Design Design Specifications Services Overview ECS Audio/Video Conferencing Fasterdata IPv6 Network Network Performance Tools (perfSONAR) ESnet OID Registry PGP Key Service Virtual Circuits (OSCARS) OSCARS Case Study Documentation User Manual FAQ Design Specifications Functional Specifications Notifications Publications Authorization Policy Default Attributes Message Security Clients For Developers Interfaces Links Hardware Requirements DOE Grids Service Transition Contact Us Technical Assistance: 1 800-33-ESnet (Inside the US) 1 800-333-7638 (Inside the US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Design Specifications OSCARS Reservation Manager - Design Specifications Year 3 Update (DRAFT) David Robertson, Chin Guok

391

Case 31-2014 A 50-Year-Old Man with Back Pain, Fatigue, Weight Loss, and Knee Swelling  

Science Journals Connector (OSTI)

...and fatigue with exertion. He had a history of obesity, depression, gout, nephrolithiasis, an adrenal nodule, and elevated results of liver-function tests, as well as one episode of iritis of the left eye 15 years before admission. He had also undergone numerous orthopedic procedures after traumatic injuries... A 50-year-old man with fatigue, weight loss, joint pain, knee swelling, and chronic back pain was admitted to the hospital because of abnormal findings on magnetic resonance imaging of the spine. Diagnostic tests were performed.

Fisher M.C.Stone J.H.Palmer W.E.

2014-10-09T23:59:59.000Z

392

A high temperature fatigue life prediction computer code based on the total strain version of StrainRange Partitioning (SRP)  

SciTech Connect (OSTI)

A recently developed high-temperature fatigue life prediction computer code is presented and an example of its usage given. The code discussed is based on the Total Strain version of Strainrange Partitioning (TS-SRP). Included in this code are procedures for characterizing the creep-fatigue durability behavior of an alloy according to TS-SRP guidelines and predicting cyclic life for complex cycle types for both isothermal and thermomechanical conditions. A reasonably extensive materials properties database is included with the code.

Mcgaw, M.A.; Saltsman, J.F.

1993-10-01T23:59:59.000Z

393

Design and Analysis of the ITER Vertical Stability Coils  

SciTech Connect (OSTI)

The ITER vertical stability (VS) coils have been developed through the preliminary design phase by Princeton Plasma Physics Laboratory (PPPL). Final design, prototyping and construction will be carried out by the Chinese Participant Team contributing lab, Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The VS coils are a part of the in-vessel coil systems which include edge localized mode (ELM) coils as well as the VS coils. An overview of the ELM coils is provided in another paper at this conference. 15 The VS design employs four turns of stainless steel jacketed mineral insulated copper (SSMIC) conductors The mineral insulation is Magnesium Oxide (MgO). Joule and nuclear heat is removed by water flowing at 3 m/s through the hollow copper conductor. A key element in the design is that slightly elevated temperatures in the conductor and its support spine during operation impose compressive stresses that mitigate fatigue damage. Away from joints, and break-outs, conductor thermal stresses are low because of the axisymmetry of the winding (there are no corner bends as in the ELM coils).The 120 degree segment joint, and break-out or terminal regions are designed with similar but imperfect constraint compared with the ring coil portion of the VS. The support for the break-out region is made from a high strength copper alloy, CuCrZr. This is needed to conduct nuclear heat to the actively cooled conductor and to the vessel wall. The support "spine" for the ring coil portion of the VS is 316 stainless steel, held to the vessel with preloaded 718 bolts. Lorentz loads resulting from normal operating loads, disruption loads and loads from disruption currents in the support spine shared with vessel, are applied to the VS coil. The transmission of the Lorentz and thermal expansion loads from the "spine" to the vessel rails is via friction augmented with a restraining "lip" to ensure the coil frictional slip is minimal and acceptable. Stresses in the coil, joints, and break-outs are presented. These are compared with static and fatigue allowables. Design for fatigue is much less demanding than for the ELM coils. A total of 30,000 cycles is required for VS design. Loads on the vessel due to the thermal expansion of the coil and spine are significant. Efforts to reduce these by reducing the cross section of the spine have been made but the vessel still must support loads resulting from restraint of thermal expansion.

Peter H. Titus, et. al.

2012-09-06T23:59:59.000Z

394

Curved and diffuse interface effects on the nuclear surface tension  

E-Print Network [OSTI]

We redefine the surface tension coefficient for a nuclear Fermi-liquid drop with a finite diffuse layer. Following Gibbs-Tolman concept, we introduce the equimolar radius R_e of sharp surface droplet at which the surface tension is applied and the radius of tension surface R_s which provides the minimum of the surface tension coefficient \\sigma. This procedure allows us to derive both the surface tension and the corresponding curvature correction (Tolman length) correctly for the curved and diffuse interface. We point out that the curvature correction depends significantly on the finite diffuse interface. This fact is missed in traditional nuclear considerations of curvature correction to the surface tension. We show that Tolman's length \\xi is negative for nuclear Fermi-liquid drop. The value of the Tolman length is only slightly sensitive to the Skyrme force parametrization and equals \\xi=-0.36 fm.

V. M. Kolomietz; S. V. Lukyanov; A. I. Sanzhur

2012-01-30T23:59:59.000Z

395

Photon Green Functions in Curved Space-Time  

E-Print Network [OSTI]

Quantization of electrodynamics in curved space-time in the Lorenz gauge and with arbitrary gauge parameter makes it necessary to study Green functions of non-minimal operators with variable coefficients. Starting from the integral representation of photon Green functions, we link them to the evaluation of integrals involving Gamma-functions. Eventually, the full asymptotic expansion of the Feynman photon Green function at small values of the world function, as well as its explicit dependence on the gauge parameter, are obtained without adding by hand a mass term to the Faddeev-Popov Lagrangian. Coincidence limits of second covariant derivatives of the associated Hadamard function are also evaluated, as a first step towards the energy-momentum tensor in the non-minimal case.

Giuseppe Bimonte; Enrico Calloni; Luciano Di Fiore; Giampiero Esposito; Leopoldo Milano; Luigi Rosa

2005-11-23T23:59:59.000Z

396

Periodic relativity: deflection of light, acceleration, rotation curves  

E-Print Network [OSTI]

Vectorial analysis relating to derivation of deflection of light is presented. Curvilinear acceleration is distinguished from the Newtonian polar conic acceleration. The difference between the two is due to the curvature term. Lorentz invariant expression for acceleration is derived. A physical theory of rotation curves of galaxies based on second solution to Einstein's field equation is presented. Theory is applied to Milky Way, M31, NGC3198 and Solar system. Modified Kepler's third law yields correct orbital periods of stars in a galaxy. Deviation factor in the line element of the theory happens to be the ratio of the Newtonian gravitational acceleration to the measured acceleration of the star in the galaxy. Therefore this deviation factor can replace the MOND function.

Vikram H. Zaveri

2014-12-08T23:59:59.000Z

397

Determination of Tafel constants in nonlinear polarization curves. Master's thesis  

SciTech Connect (OSTI)

The presence of nonlinear behavior in potentiodynamic polarization plots has resulted in difficulty in determining the Tafel constants from such plots. A FORTRAN-based program involving numerical-differentiation techniques was used to determine the existence of the Tafel regions. Various alloys polarized in synthetic seawater and a 3.5% NaCl solution were analyzed. Although severe concentration polarization often dominated the cathodic branches, the techniques employed did allow for the selection of regions that approached linear behavior. The effects of concentration polarization in hindering the determination of Tafel constants were exemplified by the uncovering of a cathodic branch containing a small region where only activation polarization dominated, followed by the onset and total domination of concentration polarization. A method of determining where the anodic and cathodic currents begin to dominate the potentiodynamic polarization curve is introduced.

O'Loughlin, T.E.

1987-12-01T23:59:59.000Z

398

A Canonical High Energy Afterglow Emission Light Curve?  

E-Print Network [OSTI]

We present self consistent calculations of Synchrotron self Compton (SSC) radiation that takes place within the afterglow blast wave and External inverse Compton (EIC) radiation that takes place when flare photons (produced by an internal process) pass through the blast wave. We show that if our current interpretations of the Swift XRT data are correct, there should be a canonical high energy afterglow emission light curve. We expect that GRBs with a long term X-ray flattening or X-ray flares should show similar high energy features. The EIC emission, however, is long lasting and weak and might be outshined by the SSC emission of the forward shock. The high energy emission could be well detected by the soon to be launched GLAST satellite. Its detection could shed new light on the conditions within the emitting regions of GRBs.

Yi-Zhong Fan; Tsvi Piran

2007-05-31T23:59:59.000Z

399

Fatigue life evaluation of wire bonds in LED packages using numerical analysis  

Science Journals Connector (OSTI)

Abstract Reliability of LED packages is evaluated using several tests. When a thermal shock test, which is one of the reliability tests, is conducted, the most common failure mode is wire neck breakage. In order to evaluate the wire bonding reliability of LED packages, performing the thermal shock test is time-consuming. In this paper the wire bonding reliability for LED packages is evaluated by using numerical analysis. A wire bonding lifetime model for the thermal shock test was developed, which is based on Coffin-Manson fatigue law. The model was calibrated from fatigue data of thermal shock tests and volume averaging accumulated plastic strains. The accumulated plastic strains were calculated by using finite element analysis corresponding to the test conditions. The test conditions were changed by silicones, package sizes, wire bonding diameters, heights, and lengths. The calibrated model was used to estimate the number cycle to failure so that the wire bonding reliability for the thermal shock test was evaluated by performing the numerical analysis. Furthermore, we used a response surface methodology to study the relationship between the wire loop and the accumulated plastic strain to determine the optimal wire loop. The plastic strain was a function of diameter, height and length. At the optimal point, the number of cycle to failure for the thermal shock test was suggested using the wire bonding lifetime model.

Sung-Uk Zhang; Bang Weon Lee

2014-01-01T23:59:59.000Z

400

Thermal shock and fatigue resistance of tungsten materials under transient heat loading  

Science Journals Connector (OSTI)

Abstract Transient heat loading tests were performed on rolled pure tungsten (PW) and lanthanum oxide doped tungsten (WL10) as well as swaged+rolled potassium doped tungsten (W-K) samples using an electron beam. In thermal shock tests, the cracking threshold was 0.440.66, 0.170.22 and 0.440.66GW/m2 for PW, WL10 and W-K, respectively. The melting threshold was over 1.1GW/m2 for PW and W-K while 0.660.88GW/m2 for WL10. In thermal fatigue tests, the obvious roughening threshold was over 1000 cycles for PW and WL10 while 1100cycles for W-K. The cracking threshold was 1001000cycles for PW, 1100cycles for WL10 and over 1000cycles for W-K alloy. WL10 displayed worse thermal and fatigue resistance while W-K exhibited better properties compared with PW, which was attributed to differences in thermalmechanical properties of the three tungsten alloys, in addition to the size and number density of La2O3 particles and potassium bubbles.

Xiaoxin Zhang; Qingzhi Yan; Shaoting Lang; Min Xia; Xiang Liu; Changchun Ge

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Fatigue, fracture, and plastic collapse of offshore tubular joints using BSI PD 6493:1991  

SciTech Connect (OSTI)

The second version of the BSI Document PD 6493, on the assessment of the significance of weld defects on a fitness for purpose basis, was published in 1991. To extend the application of PD 6493 to offshore structures, a major program of research was carried out at a number of UK universities under the title of ``the Defect Assessment Programme`` sponsored by SERC/MTD Ltd. and a number of industrial companies. The program, carried out in the period 1985--1991, provided a specific methodology for the assessment of defects in tubular joints and detailed guidance on the evaluation of parameters required for fatigue and fracture assessments. The methodology includes a combined equation approach to Stress Intensity Factor (SIF) determination based on detailed knowledge of the local and global stress fields, an approach for estimation of the plastic collapse load of cracked tubular joints based on analytical and experimental studies, guidance on treatments of welding residual stresses, and data for application of the partial safety factor approach intended to enable rational treatments of uncertainties in input parameters for fracture assessment. This paper outlines key aspects of the fatigue and fracture procedures, and presents parametric equations required for application of the methodology relating to weld toe effects, degree of bending, and plastic collapse.

Cheaitani, M.J. [Billington Osborne-Moss Engineering Ltd., Maidenhead (United Kingdom); Thurlbeck, S.D. [EQE International Ltd., Warrington (United Kingdom); Burdekin, F.M. [UMIST, Manchester (United Kingdom). Dept. of Civil and Structural Engineering

1995-12-31T23:59:59.000Z

402

Matrix fatigue cracking mechanisms of alpha(2) TMC for hypersonic applications  

SciTech Connect (OSTI)

The objective of this work was to understand matrix cracking mechanisms in a unidirectional alpha[sub 2] TMC in possible hypersonic applications. A (0)[sub 8] SCS-6/Ti-24Al-11Nb (at. percent) TMC was first subjected to a variety of simple isothermal and nonisothermal fatigue cycles to evaluate the damage mechanisms in simple conditions. A modified ascent mission cycle test was then performed to evaluate the combined effects of loading modes. This cycle mixes mechanical cycling at 150 and 483 C, sustained loads, and a slow thermal cycle to 815 C. At low cyclic stresses and strains more common in hypersonic applications, environment-assisted surface cracking limited fatigue resistance. This damage mechanism was most acute for out-of-phase nonisothermal cycles having extended cycle periods and the ascent mission cycle. A simple linear fraction damage model was employed to help understand this damage mechanism. Time-dependent environmental damage was found to strongly influence out-of-phase and mission life, with mechanical cycling damage due to the combination of external loading and CTE mismatch stresses playing a smaller role. The mechanical cycling and sustained loads in the mission cycle also had a smaller role.

Gabb, T.P.; Gayda, J.

1994-02-01T23:59:59.000Z

403

Matrix fatigue cracking in {alpha}{sub 2} titanium matrix composites for hypersonic applications  

SciTech Connect (OSTI)

The objective of this work was to understand matrix cracking mechanisms in a unidirectional {alpha}{sub 2} titanium matrix composite (TMC) in possible hypersonic applications. A [0]{sub 8} SCS-6/Ti-24Al-11Nb (atomic %) TMC was first subjected to a variety of simple isothermal and nonisothermal fatigue cycles to evaluate the damage mechanisms in simple conditions. A modified ascent mission cycle test was then performed to evaluate the combined effects of loading modes. This cycle mixes mechanical cycling at 150 and 483 C, sustained loads, and a slow thermal cycle to 815 C. At low cyclic stresses and strains more common in hypersonic applications, environment-assisted surface cracking limited fatigue resistance. This damage mechanism was most acute for out-of-phase nonisothermal cycles having extended cycle periods and the ascent mission cycle. A simple linear fraction damage model was employed to help understand this damage mechanism. Time-dependent environmental damage was found to strongly influence out-of-phase and mission life, with mechanical cycling damage due to the combination of external loading and CTE mismatch stresses playing a smaller role. The mechanical cycling and sustained loads in the mission cycle also had a smaller role.

Gabb, T.P.; Gayda, J. [NASA Lewis Research Center, Cleveland, OH (United States)

1996-12-31T23:59:59.000Z

404

Effects of stress ratio and fiber orientation on fatigue crack growth behavior in APAL  

SciTech Connect (OSTI)

A new hybrid composite (APAL; Aramid Patched Aluminum Alloy), consisting of 2024-T3 aluminum alloy plate sandwiched between aramid/epoxy prepregs (HK 285/RS 1222), was developed. Fatigue crack growth behavior was examined at stress ratios of R = 0.2, 0.5 using two kinds of APAL with different fiber orientation (0{degree}/90{degree} and {+-} 45{degree} for crack direction). The APAL showed superior fatigue crack growth resistance, which may be attributed to the crack bridging effect imposed by the intact fibers in the crack wave. The magnitude of crack bridging was estimated quantitatively and determined by a new technique on the basis of the compliances of 2024-T3 aluminum alloy and APAL specimens. The crack growth rate of the APAL specimens was reduced significantly as comparison to the monolithic aluminum alloy and was not adequately correlated with the conventional stress intensity factor range ({Delta}K). It was found that the crack growth rate was successfully correlated with the effective stress intensity factor range ( {Delta}K{sub eff} = K{sub br} {minus} K{sub cl}) allowing for the crack closure and the crack bridging. The relation between da/dN and {Delta}K{sub eff} was plotted within a narrow scatter band regardless at loading line of 2024-T3 aluminum alloy, two kinds of the APAL (APAL 0{degree}/90{degree}, APAL {+-} 45{degree}) and two kinds of stress ratios (R = 0.2, 0.5).

Oh, S.W.; Park, W.J. [Dong-A Univ., Pusan (Korea, Republic of). Dept. of Mechanical Engineering; Yoon, H.K.; Lee, K.G. [Dong-Eui Univ., Pusan (Korea, Republic of). Dept. of Mechanical Engineering; Cho, J.M.; Lee, K.B. [Han Kuk Fiber Glass Co. Ltd., Kyungnam (Korea, Republic of)

1993-12-31T23:59:59.000Z

405

Improvement in surface fatigue life of hardened gears by high-intensity shot peening  

SciTech Connect (OSTI)

Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

Townsend, D.P.

1992-01-01T23:59:59.000Z

406

Design Considerations  

Office of Environmental Management (EM)

and leakage rates into and out of the cleanup system tend to become additional factors that must be considered in the overall design of the facility. When cleanup systems...

407

Biosystems Design  

Broader source: Energy.gov [DOE]

Breakout Session 2: Frontiers and Horizons Session 2-A: Synthetic Biology and the Promise of Biofuels Pablo Rabinowicz, Program Manager, Biosystems Design Program, Biological and Environmental Research (BER), U.S. Department of Energy

408

TONGUE-PLACED TACTILE BIOFEEDBACK SUPPRESSES THE DELETERIOUS EFFECTS OF MUSCLE FATIGUE ON JOINT POSITION SENSE AT THE ANKLE  

E-Print Network [OSTI]

POSITION SENSE AT THE ANKLE Nicolas VUILLERME, Matthieu BOISGONTIER, Olivier CHENU, Jacques DEMONGEOT of the position sense at the ankle can be disturbed by muscle fatigue, it recently also has been shown to be improved, under normal ankle neuromuscular state, through the use of an artificial tongue-placed tactile

Paris-Sud XI, Université de

409

Micromechanisms of creep-fatigue crack growth in a silicide-matrix composite with SiC particles  

SciTech Connect (OSTI)

An experimental study has been conducted to examine the cyclic fatigue crack growth characteristics in 1,200 C air of a MoSi[sub 2]-50 mol% WSi[sub 2] alloy in the unreinforced condition and with 30 vol% SiC particles. For comparison purposes, crack growth experiments under sustained loads were also carried out in the silicide-matrix composite. Particular attention is devoted to developing an understanding of the micromechanism of subcritical crack growth by recourse to optical and electron microscopy, including transmission electron microscopy of crack-tip damage. The results indicate that enhanced viscous flow of glass films along interfaces and grain boundaries imparts pronounced levels of subcritical crack growth in the composite material; the composite exhibits a higher fatigue fracture threshold and a more extended range of stable fracture than the unreinforced alloy. The effects of glass phase in influencing fatigue crack growth in the silicide-based material are compared to the influence of in situ-formed and preexisting glass films on high-temperature cyclic fatigue crack growth in ceramics and ceramic composites. The paper concludes with a comparison of present results with the high-temperature damage tolerance of a variety of intermetallic alloys and ceramic materials.

Ramamurty, U.; Kim, A.S.; Suresh, S. (Brown Univ., Providence, RI (United States)); Petrovic, J.J. (Los Alamos National Lab., NM (United States))

1993-08-01T23:59:59.000Z

410

High-Frequency Fatigue Behavior of Woven-Fiber-Fabric-Reinforced Polymer-Derived Ceramic-Matrix Composites  

E-Print Network [OSTI]

heat exchangers, continuous-fiber-reinforced ceramic- matrix composites (CFCMCs) will encounter cyclic glass-matrix composite showed that, unlike monolithic ceramics, fatigue life of this composite decreased. The emphasis of processing research in the ceramic-matrix composite (CMC) area has increasingly shifted from

Barber, James R.

411

Fracture and Fatigue Behavior at Ambient and Elevated Temperatures of Alumina Bonded with Copper/Niobium/Copper Interlayers  

E-Print Network [OSTI]

Fracture and Fatigue Behavior at Ambient and Elevated Temperatures of Alumina Bonded with Copper and Engineering, University of California, Berkeley, California 94720 Interfacial fracture toughness and cyclic temperatures, and assessed in terms of interfacial chemistry and microstructure. The mean interfacial fracture

Ritchie, Robert

412

F A T I G U E 2 0 0 2 HIGH-CYCLE FATIGUE OF BETA TITANIUM ALLOYS  

E-Print Network [OSTI]

-object damage on jet engine fan blades is used as an engineering example of potential HCF applicationsF A T I G U E 2 0 0 2 HIGH-CYCLE FATIGUE OF BETA TITANIUM ALLOYS J. O. Peters*+ , G. Lütjering*, R) properties of the high-strength titanium alloys -Cez and Ti-6246 (in two distinctly different + processed

Ritchie, Robert

413

On the application of the KitagawaTakahashi diagram to foreign-object damage and high-cycle fatigue  

E-Print Network [OSTI]

with such HCF related failures in titanium alloy blades [1­4]. Specifically, FOD has been found to reduce the fatigue strength of fan and compressor blades, principally by causing stress-raising notches [5 for evaluating the detrimental effect of FOD on HCF failures in Ti­ 6Al­4V blade alloys. ? 2002 Elsevier Science

Hutchinson, John W.

414

Fracture toughness and fatigue-crack propagation in a ZrTiNiCuBe bulk metallic glass  

E-Print Network [OSTI]

growth and fracture toughness behavior, representing the conditions governing the subcritical amorphous alloy was also found to be susceptible to fatigue-crack growth under cyclic loading, with growth are thus available on the toughness and cyclic crack growth properties in these alloys. Accord- ingly

Ritchie, Robert

415

Estimating Carbon Supply Curves for Global Forests and Other Land Uses |  

Open Energy Info (EERE)

Estimating Carbon Supply Curves for Global Forests and Other Land Uses Estimating Carbon Supply Curves for Global Forests and Other Land Uses Jump to: navigation, search Tool Summary Name: Estimating Carbon Supply Curves for Global Forests and Other Land Uses Agency/Company /Organization: Resources for the Future Sector: Land Focus Area: Forestry, Agriculture Topics: GHG inventory, Resource assessment Resource Type: Guide/manual Website: www.rff.org/documents/RFF-DP-01-19.pdf Estimating Carbon Supply Curves for Global Forests and Other Land Uses Screenshot References: Estimating Carbon Supply Curves for Global Forests and Other Land Uses[1] Abstract "This study develops cumulative carbon "supply curves" for global forests utilizing an dynamic timber supply model for sequestration of forest carbon. Because the period of concern is the next century, and

416

Changes in stationary upright standing and proprioceptive reflex control of foot muscles after fatiguing static foot inversion  

Science Journals Connector (OSTI)

Abstract We searched for the consequences of a maximal static foot inversion sustained until exhaustion on the post-exercise stationary upright standing and the proprioceptive control of the foot muscles. Twelve healthy subjects executed an unilateral maximal static foot inversion during which continuous power spectrum analyses of surface electromyograms of the tibialis anterior (TA), peroneus longus (PL), and gastrocnemius medialis (GM) muscles were performed. Superimposed pulse trains (twitch interpolation) were delivered to the TA muscle to identify central or peripheral fatigue. Before and after the fatiguing task, we measured (1) the repartition of the plantar and barycentre surfaces with a computerized stationary platform, (2) the peak contractile TA response to electrical stimulation (TA twitch), (3) the tonic vibratory response (TVR) of TA and GM muscles, and (4) the Hoffman reflex. During static exercise, central fatigue was diagnosed in 5/12 subjects whereas in the 7 others peripheral TA fatigue was deduced from the absence of response to twitch interpolation and the post-exercise decrease in twitch amplitude. The sustained foot inversion was associated with reduced median frequency in TA but not in PL and GM muscles. After static exercise, in all subjects both the mean plantar and rearfoot surfaces increased, indicating a foot eversion, the TVR amplitude decreased in TA but did not vary in GM, and the Hoffman reflex remained unchanged. Whatever was the mechanism of fatigue during the maximal foot inversion task, the facilitating myotatic reflex was constantly altered in foot invertor muscles. This could explain the prevailing action of the antagonistic evertor muscles.

Bruno Vie; Nicolas Gomez; Christelle Brerro-Saby; Jean Paul Weber; Yves Jammes

2013-01-01T23:59:59.000Z

417

Another algebraic variational principle for the spectral curve of matrix models  

E-Print Network [OSTI]

We propose an alternative variational principle whose critical point is the algebraic plane curve associated to a matrix model (the spectral curve, i.e. the large $N$ limit of the resolvent). More generally, we consider a variational principle that is equivalent to the problem of finding a plane curve with given asymptotics and given cycle integrals. This variational principle is not given by extremization of the energy, but by the extremization of an "entropy".

B. Eynard

2014-07-31T23:59:59.000Z

418

Geodesic Bezier Curves: a Tool for Modeling on Triangulations Dimas Martinez Morera Paulo Cezar Carvalho Luiz Velho  

E-Print Network [OSTI]

Geodesic B´ezier Curves: a Tool for Modeling on Triangulations Dimas Mart´inez Morera Paulo Cezar is trimmed, final result. Abstract We define a new class of curves, called geodesic B´ezier curves care is taken to achieve interactive rates for modeling tasks. Keywords: Geodesic B´ezier Curve

419

Estimating Energy Efficiency Technology Adoption Curve Elasticity with Respect to Government and Utility Deployment Program Indicators  

E-Print Network [OSTI]

Energy Efficiency Technology Adoption Curve Elasticity withEnvironmental Energy Technologies Division Ernest OrlandoEnergy, Building Technologies Office under Contract no. DE-

Van Buskirk, Robert

2014-01-01T23:59:59.000Z

420

Accounting for Technological Change in Regulatory Impact Analyses: The Learning Curve Technique  

E-Print Network [OSTI]

learning curves for energy technology policy: A component-publicly supported energy technologies." Energy Policy 37(in renewable energy technologies." Energy Policy 34(2006):

Taylor, Margaret

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Sixth Northwest Conservation and Electric Power Plan Appendix E: Conservation Supply Curve  

E-Print Network [OSTI]

Sixth Northwest Conservation and Electric Power Plan Appendix E: Conservation Supply Curve....................................................................................................... 11 Value of Energy Saved ............................................................................................................. 11 Value of Deferred Transmission and Distribution Capacity

422

A Tunable Hemispherical Platform for Non-Stretching Curved Flexible Electronics and Optoelectronics  

E-Print Network [OSTI]

Flexible Electronics and Optoelectronics Jinda Zhuang and Y.flexible electronics or optoelectronics on curved surfacesflexible electronics and optoelectronics for a wide variety

Ju, Y. Sungtaek

2014-01-01T23:59:59.000Z

423

A rigid analytical regulator for the K_2 of Mumford curves.  

E-Print Network [OSTI]

We construct a rigid analytical regulator for the K_2 of Mumford curves, a non-archimedean analogue of the complex analytical Beilinson-Bloch-Deligne regulator.

Ambrus Pal

424

E-Print Network 3.0 - alternative temperature-time curves Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

each other so that sections of one... Grouping Curved Lines Paul L. Rosin Institute for Remote ... Source: Rosin, Paul - School of Computer Science, University of Wales, Cardiff...

425

Effects of banked-curves on ankle and knee kinematics during running.  

E-Print Network [OSTI]

??Given that a greater injury incidence has been shown for indoor versus outdoor running tracks, attention to mechanical differences in curve running is warranted. Hence, (more)

De Garie, Luc.

2006-01-01T23:59:59.000Z

426

Disk-averaged Spectra & light-curves of Earth  

E-Print Network [OSTI]

We are using computer models to explore the observational sensitivity to changes in atmospheric and surface properties, and the detectability of biosignatures, in the globally averaged spectra and light-curves of the Earth. Using AIRS (Atmospheric Infrared Sounder) data, as input for atmospheric and surface properties, we have generated spatially resolved high-resolution synthetic spectra using the SMART radiative transfer model, for a variety of conditions, from the UV to the far-IR (beyond the range of current Earth-based satellite data). We have then averaged over the visible disk for a number of different viewing geometries to quantify the sensitivity to surface types and atmospheric features as a function of viewing geometry, and spatial and spectral resolution. These results have been processed with an instrument simulator to improve our understanding of the detectable characteristics of Earth-like planets as viewed by the first generation extrasolar terrestrial planet detection and characterization missions (Terrestrial Planet Finder/Darwin and Life finder). The wavelength range of our results are modelled over are applicable to both the proposed visible coronograph and mid-infrared interferometer TPF architectures. We have validated this model against disk-averaged observations by the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES). This model was also used to analyze Earth-shine data for detectability of planetary characteristics and biosignatures in disk-averaged spectra.

G. Tinetti; V. S. Meadows; D. Crisp; W. Fong; N. Kiang; E. Fishbein; T. Velusamy; E. Bosc; M. Turnbull

2005-02-11T23:59:59.000Z

427

Numerical simulation of laminar flow in a curved duct  

SciTech Connect (OSTI)

This paper describes numerical simulations that were performed to study laminar flow through a square duct with a 900 bend. The purpose of this work was two fold. First, an improved understanding was desired of the flow physics involved in the generation of secondary vortical flows in three-dimensions. Second, adaptive gridding techniques for structured grids in three- dimensions were investigated for the purpose of determining their utility in low Reynolds number, incompressible flows. It was also of interest to validate the commercial computer code CFD-ACE. Velocity predictions for both non-adaptive and adaptive grids are compared with experimental data. Flow visualization was used to examine the characteristics of the flow though the curved duct in order to better understand the viscous flow physics of this problem. Generally, moderate agreement with the experimental data was found but shortcomings in the experiment were demonstrated. The adaptive grids did not produce the same level of accuracy as the non-adaptive grid with a factor of four more grid points.

Lopez, A.R.; Oberkampf, W.L.

1995-01-01T23:59:59.000Z

428

The anatomy of $\\gamma$-ray pulsar light curves  

E-Print Network [OSTI]

We previously obtained constraints on the viewing geometries of 6 Fermi LAT pulsars using a multiwavelength approach (Seyffert et al., 2011). To obtain these constraints we compared the observed radio and $\\gamma$-ray light curves (LCs) for those 6 pulsars by eye to LCs predicted by geometric models detailing the location and extent of emission regions in a pulsar magnetosphere. As a precursor to obtaining these constraints, a parameter study was conducted to reinforce our qualitative understanding of how the underlying model parameters effect the LCs produced by the geometric models. Extracting useful trends from the $\\gamma$-ray model LCs proved difficult though due to the increased complexity of the geometric models for the $\\gamma$-ray emission relative to those for the radio emission. In this paper we explore a second approach to investigating the interplay between the model parameters and the LC atlas. This approach does not attempt to understand how the set of model parameters influences the LC shapes ...

Seyffert, A S; Johnson, T J; Harding, A K

2015-01-01T23:59:59.000Z

429

Moving boundary approximation for curved streamer ionization fronts: Solvability analysis  

Science Journals Connector (OSTI)

The minimal density model for negative streamer ionization fronts is investigated. An earlier moving boundary approximation for this model consisted of a kinetic undercooling type boundary condition in a Laplacian growth problem of Hele-Shaw type. Here we derive a curvature correction to the moving boundary approximation that resembles surface tension. The calculation is based on solvability analysis with unconventional features, namely, there are three relevant zero modes of the adjoint operator, one of them diverging; furthermore, the inner-outer matching ahead of the front must be performed on a line rather than on an extended region; and the whole calculation can be performed analytically. The analysis reveals a relation between the fields ahead and behind a slowly evolving curved front, the curvature and the generated conductivity. This relation forces us to give up the ideal conductivity approximation, and we suggest to replace it by a charge neutrality approximation. This implies that the electric potential in the streamer interior is no longer constant but solves a Laplace equation; this leads to a Muskat-type problem.

Fabian Brau, Benny Davidovitch, and Ute Ebert

2008-11-21T23:59:59.000Z

430

Remarks on the concept of dispersion in a curved linac  

SciTech Connect (OSTI)

A next-generation linear collider is expected to span tens of kilometers in length. For various reasons, it may be desirable to house such an accelerator in a tunnel that follows the earth's curvature rather that in a 'laser-straight' tunnel. One side effect of opting for a curved linac is the introduction of vertical dispersion. In recent years, much work has been dedicated to understand and evaluate the impact of the presence of dispersion on emittance preservation. While performing simulations with our in-house code (CHEF) we observed a discrepancy between the dispersion function it produces and that computed using other codes in use within the accelerator community. Understanding the origin and the meaning of this discrepancy required a re-examination of the meaning of the concept of dispersion in the context of a linac. The object of this note is to document our findings. We establish that the default dispersion algorithm used by CHEF corresponds to a different, and ultimately more appropriate, definition of the dispersion in presence of acceleration. Not surprisingly, a consistent definition of dispersion restores agreement between codes.

Ostiguy, Jean-Francois; /Fermilab

2009-01-01T23:59:59.000Z

431

Aircraft Design  

Science Journals Connector (OSTI)

... his subject is more applied than academic, making it appear to be a designer's handbook rather than a student's text-book. Even then he falls between two stools ... falls between two stools, giving neither enough facts and figures for the one, nor fundamental proofs for the other. Nevertheless the subject matter, so far as it goes, ...

1940-03-09T23:59:59.000Z

432

DESIGN SUPPORT TOOLS 599 INTERNATIONAL DESIGN CONFERENCE -DESIGN 2012  

E-Print Network [OSTI]

DESIGN SUPPORT TOOLS 599 INTERNATIONAL DESIGN CONFERENCE - DESIGN 2012 Dubrovnik - Croatia, May 21 - 24, 2012. CAN COMPUTER GRAPHIC SYSTEM BE USED TO INFORM DESIGNERS ABOUT INCLUSIVITY? E. Zitkus, P. Langdon and P. J. Clarkson Keywords: inclusive design, accessibility, CAD, design process 1. Introduction

Crilly, Nathan

433

Meta-Design--Design for Designers Gerhard Fischer  

E-Print Network [OSTI]

1 Meta-Design--Design for Designers Gerhard Fischer Center for LifeLong Learning and Design (L3 D-0430 USA gerhard@cs.colorado.edu Eric Scharff Center for LifeLong Learning and Design (L3 D) Department scharffe@cs.colorado.edu ABSTRACT One fundamental challenge for the design of the interactive systems

Fischer, Gerhard

434

Effects of austempering temperature on fatigue crack rate propagation in a series of modified (Cu, Ni, and/or Mo) nodular irons  

Science Journals Connector (OSTI)

Studies on austempered nodular cast irons were carried out to establish the optimum isothermic heat treatment at a given chemical composition that rendered the highest fatigue crack propagation resistance. Sev...

M. Martnez-Madrid; R. Rodrguez-T

2002-12-01T23:59:59.000Z

435

Validation of the state-space model of fatigue crack growth in ductile alloys under variable-amplitude load via comparison of the crack-opening stress data  

Science Journals Connector (OSTI)

A state-space model of fatigue crack growth in ductile alloys under variable-amplitude load was presented by Patankar and Ray (Patankar...International Journal of Fracture, 90, 235--249; Patankar and Ray (2000).

Ravindra Patankar; Rong Qu

2005-02-01T23:59:59.000Z

436

RADIOACTIVELY POWERED RISING LIGHT CURVES OF TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

The rising luminosity of the recent, nearby supernova 2011fe shows a quadratic dependence with time during the first Almost-Equal-To 0.5-4 days. In addition, studies of the composite light curves formed from stacking together many Type Ia supernovae (SNe Ia) have found similar power-law indices for the rise, but may also show some dispersion that may indicate diversity. I explore what range of power-law rises are possible due to the presence of radioactive material near the surface of the exploding white dwarf (WD). I summarize what constraints such a model places on the structure of the progenitor and the distribution and velocity of ejecta. My main conclusion is that for the inferred explosion time for SN 2011fe, its rise requires an increasing mass fraction X {sub 56} Almost-Equal-To (4-6) Multiplication-Sign 10{sup -2} of {sup 56}Ni distributed between a depth of Almost-Equal-To 10{sup -2} and 0.3 M {sub Sun} below the WD's surface. Radioactive elements this shallow are not found in simulations of a single C/O detonation. Scenarios that may produce this material include helium-shell burning during a double-detonation ignition, a gravitationally confined detonation, and a subset of deflagration to detonation transition models. In general, the power-law rise can differ from quadratic depending on the details of the velocity, density, and radioactive deposition gradients in a given event. Therefore, comparisons of this work with observed bolometric rises of SNe Ia would place strong constraints on the properties of the shallow outer layers, providing important clues for identifying the elusive progenitors of SNe Ia.

Piro, Anthony L., E-mail: piro@caltech.edu [Theoretical Astrophysics, California Institute of Technology, 1200 East California Boulevard, M/C 350-17, Pasadena, CA 91125 (United States)

2012-11-10T23:59:59.000Z

437

Particle detectors in curved spacetime quantum field theory  

E-Print Network [OSTI]

Unruh-DeWitt particle detector models are studied in a variety of time-dependent and time-independent settings. We work within the framework of first-order perturbation theory and couple the detector to a massless scalar field. The necessity of switching on (off) the detector smoothly is emphasised throughout, and the transition rate is found by taking the sharp-switching limit of the regulator-free and finite response function. The detector is analysed on a variety of spacetimes: $d$-dimensional Minkowski, the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole, the two-dimensional Minkowski half-plane, two-dimensional Minkowski with a receding mirror, and the two- and four-dimensional Schwarzschild black holes. In $d$-dimensional Minkowski spacetime, the transition rate is found to be finite up to dimension five. In dimension six, the transition rate diverges unless the detector is on a trajectory of constant proper acceleration, and the implications of this divergence to the global embedding spacetime (GEMS) methods are studied. In three-dimensional curved spacetime, the transition rate for the scalar field in an arbitrary Hadamard state is found to be finite and regulator-free. Then on the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole spacetime, we analyse the detector coupled to the field in the Hartle-Hawking vacua, under both transparent and reflective boundary conditions at infinity. Results are presented for the co-rotating detector, which responds thermally, and for the radially-infalling detector. In four-dimensional Schwarzschild spacetime, we proceed numerically, and the Hartle-Hawking, Boulware and Unruh vacua rates are compared. Results are presented for the case of the static detectors, which respond thermally, and also for the case of co-rotating detectors.

Lee Hodgkinson

2013-09-27T23:59:59.000Z

438

Thermal stability of curved ray tomography for corrosion monitoring  

SciTech Connect (OSTI)

Guided wave tomography is being developed as an effective tool for continuous monitoring of corrosion and erosion depth in pipelines. A pair of transmit- and receive-ring arrays of ultrasonic transducers encircles the pipe and delimits the section to be monitored. In curved ray tomography (CRT), the depth profile is estimated from the time delay matrix, ??, whose ij-th entry is the phase traveltime difference between the current and baseline signals measured between transducers i and j of the transmit and receive-ring arrays, respectively. Under perfectly stable experimental conditions, the non-zero entries of ?? are only due to the occurrence of damage and provide a reliable input to CRT. However, during field operation, ?? can develop non-zero entries due to a number of environmental changes ranging from temperature variations to degradation of transducer-pipe coupling and transducer intrinsic performance. Here, we demonstrate that these sources of instability can be eliminated by exploiting the spatial diversity of array measurements in conjunction with EMAT transducer technology which is intrinsically stable owing to its non-contact nature. The study is based on a full-scale experiment performed on a schedule 40, 8 diameter, 3 m length steel pipe, monitored with two EMAT ring arrays. It is shown that for an irregularly shaped defect the proposed method yields maximum depth estimations that are as accurate as single point ultrasonic thickness gaging measurements and over a wide temperature range up to 175C. The results indicate that advanced inversion schemes in combination with EMAT transduction offer great potential for continuously monitoring the progression of corrosion or erosion damage in the oil and gas industry.

Willey, C. L. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221 (United States); Simonetti, F.; Nagy, P. B. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, OH 45221,USA and Cincinnati NDE, Cincinnati, OH 45244 (United States); Instanes, G. [ClampOn AS, 5162 Laksevaag, Bergen, Norway and Cincinnati NDE, Cincinnati, OH 45244 (United States)

2014-02-18T23:59:59.000Z

439

Manhattan Project: Y-12: Design, 1942-1943  

Office of Scientific and Technical Information (OSTI)

Ernest Lawrence slumps in his chair from fatigue in front of a cyclotron control panel while conducting calutron-related experiments, Berkeley, 1943. Y-12: DESIGN Ernest Lawrence slumps in his chair from fatigue in front of a cyclotron control panel while conducting calutron-related experiments, Berkeley, 1943. Y-12: DESIGN (Oak Ridge: Clinton, 1942-1943) Events > The Uranium Path to the Bomb, 1942-1944 Y-12: Design, 1942-1943 Y-12: Construction, 1943 Y-12: Operation, 1943-1944 Working K-25 into the Mix, 1943-1944 The Navy and Thermal Diffusion, 1944 Although the Lewis Report had placed gaseous diffusion ahead of the electromagnetic approach, many were still betting in early 1943 that Ernest Lawrence (right) and his "calutron" would eventually predominate. Lawrence and his laboratory of mechanics at the University of California, Berkeley, continued to experiment with the giant 184-inch cyclotron magnet, trying to reach a consensus on which shims, sources, and Electromagnetic method for the enrichment of uranium collectors to incorporate into the Y-12 Electromagnetic Plant that was to be built at Oak Ridge. Research on magnet size and placement and beam resolution led Lawrence and his group in fall 1942 to propose an arrangement of huge electromagnetic coils connected by a bus bar in an oval racetrack configuration, as seen from above. Forty-eight gaps in the racetrack between the coils would each contain two vacuum tanks. With two racetracks per building, ten buildings would be necessary to provide the estimated 2,000 sources and collectors needed to separate 100 grams of uranium-235 daily. The Berkeley researchers hoped that improvements in calutron design, or placing multiple sources and collectors in each tank, might increase efficiency and reduce the number of tanks and buildings required, but experimental results were inconclusive even as Stone & Webster of Boston, the Y-12 contractor at Oak Ridge, prepared to break ground.

440

Inuence of foreign-object damage on crack initiation and early crack growth during high-cycle fatigue of Ti6Al4V  

E-Print Network [OSTI]

; Ti±6Al±4V 1. Introduction The high-cycle fatigue (HCF) of aircraft gas-turbine engine components has of small surface fatigue cracks in a Ti±6Al±4V alloy, processed for typical turbine blade applications microcracks in the damaged zone (seen only at the higher impact velocities). Furthermore, the eect of residual

Ritchie, Robert

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Geodesic Completeness for Sobolev Metrics on the Space of Immersed Plane Curves  

E-Print Network [OSTI]

Geodesic Completeness for Sobolev Metrics on the Space of Immersed Plane Curves Martins Bruveris on the space of immersed plane curves. We show that the geodesic equation for Sobolev-type met- rics is geodesically com- plete. We find lower bounds for the geodesic distance in terms of curvature and its

Michor, Peter W.

442

Motion of Spin 1/2 Massless Particle in a Curved Spacetime. I. Lagrangian Approach  

E-Print Network [OSTI]

Quasi-classical picture of motion of spin 1/2 massless particle in a curved spacetime is built on base of simple Lagrangian model. The one is constructed due to analogy with Lagrangian of massive spin 1/2 particle. Equations of motion and spin propagation coincide with Papapetrou equations describing dynamic of photon in a curved spacetime.

A. T. Muminov

2008-02-18T23:59:59.000Z

443

Motion of Spin 1/2 Massive Particle in a Curved Spacetime  

E-Print Network [OSTI]

Quasi-classical picture of motion of spin 1/2 massive particle in a curved spacetime is built on base of simple Lagrangian model. The one is constructed due to analogy with Lagrangian of massive vector particle. Equations of motion and spin propagation coincide with Papapetrou equations describing dynamic of classical spinning particle in a curved spacetime.

A. T. Muminov

2007-09-28T23:59:59.000Z

444

Abstract Title: Comprehensive assessment of peripheral arteries using multi-path curved planar  

E-Print Network [OSTI]

reformation of CTA datasets Author Block: A. Koechl, A. Kanitsar, F. Lomoschitz, E. Groeller, D. Fleischmann - Purpose: To assess the diagnostic efficiency of multi-path curved planar reformations (mpCPR), a new image composite views (over a 180° range), which simultaneously display curved planar reformations through each

445

POLYNOMIAL REPRESENTATION OF SOME SHIP SECTION AREA CURVES AND THE CALCULATION OF THE ASSOCIATED WAVE RESISTANCE  

Science Journals Connector (OSTI)

......the mean draught of the ship, and g is the acceleration...but only the com- bined effects of wave resistance and...POLYNOMIAL REPRESENTATION OF SHIP SECTION AREA CURVES 61...POLYNOMIAL REPRESENTATION OF SHIP SECTION AREA CURVES 53...xm, so that the effect of passing from yn(x......

D. W. MARTIN

1961-02-01T23:59:59.000Z

446

On-line monitoring of power curves Andrew Kusiak*, Haiyang Zheng, Zhe Song  

E-Print Network [OSTI]

. The power coefficient indicates the effi- ciency of a turbine capturing the wind energy, and it is optimized and Industrial Engineering, 3131 Seamans Center, The University of Iowa, Iowa City, IA 52242 ­ 1527, USA a r t i of wind turbines is presented. Turbine performance is captured with a power curve. The power curves

Kusiak, Andrew

447

Soil-Water Characteristic Curve Modeling at Low Water Content: Empirical and Semi-Empirical Approaches  

E-Print Network [OSTI]

Soil-Water Characteristic Curve Modeling at Low Water Content: Empirical and Semi model, the Modified Kovacs (MK) model for the determination of soil-water characteristic curve at the low water contents of two horizons of a soil from Burkina Faso. Combining terms from capillary state

Paris-Sud XI, Université de

448

Use of Artificial Neural Network for the Construction of Lorenz Curve  

Science Journals Connector (OSTI)

Lorenz curve and Gini index are the most widely used measures of income inequality in Economics. Artificial Neural Networks (ANN) are mathematical models that learn complex relationships in data. ANN is widely used for prediction and classification tasks ... Keywords: Artificial Neural Network, Back Propagation Algorithm, Gini Index, Lorenz Curve, Multi Layer Perceptron

Sudesh Pundir, Ganesan R.

2014-01-01T23:59:59.000Z

449

Fabrication of curved-line nanostructures on membranes for transmission electron microscopy investigations of domain walls  

E-Print Network [OSTI]

Fabrication of curved-line nanostructures on membranes for transmission electron microscopy, Cambridge CB2 3QZ, United Kingdom Available online 28 February 2006 Abstract We have fabricated curved-line ferromagnetic nanostructures on membranes for transmission electron microscopy investigations of the equilibrium

Dunin-Borkowski, Rafal E.

450

A constructive empirical theory for metal fatigue under block cyclic loading  

Science Journals Connector (OSTI)

...for g. Note that our assumed g does not include explicit dependence...Military handbook (1998) MIL-HDBK-5H. Every single S-N curve...psi+c, for any constant c, does not affect the theory. Since...any constant c greater than 0, does not change the form of the evolution...

2008-01-01T23:59:59.000Z

451

Low Carbon Growth: a Potential Path for Mexico - GHG Abatement Cost Curve |  

Open Energy Info (EERE)

Growth: a Potential Path for Mexico - GHG Abatement Cost Curve Growth: a Potential Path for Mexico - GHG Abatement Cost Curve (Redirected from Mexico-McKinsey GHG Abatement Cost Curve) Jump to: navigation, search Name Low Carbon Growth: a Potential Path for Mexico - GHG Abatement Cost Curve Agency/Company /Organization Centro Mario Molina, McKinsey and Company Sector Energy, Land Focus Area Energy Efficiency, Renewable Energy Topics Resource assessment, Background analysis Website http://www.esmap.org/filez/pub Country Mexico Central America References ESMAP Low Carbon Growth Country Studies Program[1] References ↑ "ESMAP Low Carbon Growth Country Studies Program" Retrieved from "http://en.openei.org/w/index.php?title=Low_Carbon_Growth:_a_Potential_Path_for_Mexico_-_GHG_Abatement_Cost_Curve&oldid=3289

452

Methods for the Precise Locating and Forming of Arrays of Curved Features into a Workpiece  

DOE Patents [OSTI]

Methods for manufacturing high precision arrays of curved features (e.g. lenses) in the surface of a workpiece are described utilizing orthogonal sets of inter-fitting locating grooves to mate a workpiece to a workpiece holder mounted to the spindle face of a rotating machine tool. The matching inter-fitting groove sets in the workpiece and the chuck allow precisely and non-kinematically indexing the workpiece to locations defined in two orthogonal directions perpendicular to the turning axis of the machine tool. At each location on the workpiece a curved feature can then be on-center machined to create arrays of curved features on the workpiece. The averaging effect of the corresponding sets of inter-fitting grooves provide for precise repeatability in determining, the relative locations of the centers of each of the curved features in an array of curved features.

Gill, David Dennis (Albuquerque, NM); Keeler, Gordon A. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Mukherjee, Sayan D. (Albuquerque, NM)

2008-10-14T23:59:59.000Z

453

Materials characterization of silicon carbide reinforced titanium (Ti/SCS-6) metal matrix composites. Part 2: Theoretical modeling of fatigue behavior  

SciTech Connect (OSTI)

Flexural fatigue behavior was investigated on titanium (Ti-15V-3Cr) metal matrix composites reinforced with cross-ply, continuous silicon carbide (SiC) fibers. The titanium composites had an eight-ply (0, 90, +45, {minus}45 deg) symmetric layup. Mechanistic investigation of the fatigue behavior is presented in Part 1 of this series. In Part 2, theoretical modeling of the fatigue behavior was performed using finite element techniques to predict the four stages of fatigue deflection behavior. On the basis of the mechanistic understanding, the fiber and matrix fracture sequence was simulated from ply to ply in finite element modeling. The predicted fatigue deflection behavior was found to be in good agreement with the experimental results. Furthermore, it has been shown that the matrix crack initiation starts in the 90 deg ply first, which is in agreement with the experimental observation. Under the same loading condition, the stress in the 90 deg ply of the transverse specimen is greater than that of the longitudinal specimen. This trend explains whey the longitudinal specimen has a longer fatigue life than the transverse specimen, as observed in Part 1.

Chiang, K.T.; Loh, D.H. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.; Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Diaz, E.S. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

1995-12-01T23:59:59.000Z

454

Institute of Design Institute of Design  

E-Print Network [OSTI]

Institute of Design Institute of Design 350 N. LaSalle St. Chicago, IL 60610 312.595.4900 design The Institute of Design has continuously explored emerg- ing ideas about how design interacts with society languages and use of new media and material. The school was renamed the Institute of Design (ID) in 1944

Heller, Barbara

455

Theory manual for FAROW version 1.1: A numerical analysis of the Fatigue And Reliability Of Wind turbine components  

SciTech Connect (OSTI)

Because the fatigue lifetime of wind turbine components depends on several factors that are highly variable, a numerical analysis tool called FAROW has been created to cast the problem of component fatigue life in a probabilistic framework. The probabilistic analysis is accomplished using methods of structural reliability (FORM/SORM). While the workings of the FAROW software package are defined in the user's manual, this theory manual outlines the mathematical basis. A deterministic solution for the time to failure is made possible by assuming analytical forms for the basic inputs of wind speed, stress response, and material resistance. Each parameter of the assumed forms for the inputs can be defined to be a random variable. The analytical framework is described and the solution for time to failure is derived.

WUBTERSTEUBMSTEVEB R.; VEERS,PAUL S.

2000-01-01T23:59:59.000Z

456

Effect of TiN coatings on the rolling contact fatigue behavior of M50 bearing steel. Final report  

SciTech Connect (OSTI)

There is a continuing requirement for improved bearing performance for both commercial and military applications. Service temperatures are increasing steadily due to increased power requirements and corrosion of components remains a major concern as well, particularly for bearings in military systems. In our ongoing study, a number of different coatings were applied to VIM-VAR M50 bearing steel to improve both corrosion resistance and rolling contact fatigue behavior. This report deals specifically with coatings produced by the ion beam assisted deposition IBAD of TiN, details of the coating process, and test results obtained. The rolling contact fatigue performance of IBAD TiN coated M50 samples demonstrated increased lifetime performance and durability for a 1 micrometer thick coating. Preliminary data on corrosion properties is also presented.

Middleton, R.M.; Huang, P.J.; Wells, M.G.; Kant, R.A.

1992-12-01T23:59:59.000Z

457

Thermal Fatigue of Polycrystalline Copper in CLIC Accelerating Structures: Surface Roughening and Hardening as a Function of Grain Orientation  

E-Print Network [OSTI]

The accelerating structures of CLIC will be submitted to 2 x 1010 thermal-mechanical fatigue cycles, arising from Radio Frequency (RF) induced eddy currents, causing local superficial cyclic heating. In order to assess the effects of superficial fatigue, high temperature annealed OFE Copper samples were thermally fatigued with the help of pulsed laser irradiation. They underwent postmortem Electron Backscattered Diffraction (EBSD) measurements and?hardness observations. Previous work has confirmed that surface roughening depends on the orientation of near-surface grains*,**. It is clearly observed that, through thermal cycling, the increase of hardness of a crystallographic direction is related to the amount of surface roughening induced by fatigue. Near-surface grains, oriented [1 0 0] with respect to the surface, exhibiting ver...

Aicheler, M

2010-01-01T23:59:59.000Z

458

Effect of heat treatment and heat-to-heat variations in the fatigue-crack growth response of Alloy 718  

SciTech Connect (OSTI)

The fatigue-crack growth behavior of seven heats of Alloy 718 was studied at five different test temperatures. These seven heats represented at least four different producers, four different product forms, two melt practices, and most of the heat were tested in two different heat-treated conditions. Heat-to-heat variations were noted; these were most obvious in material given the conventional heat-treatment. 8 figs., 5 tabs.

James, L.A.; Mills, W.J.

1980-04-01T23:59:59.000Z

459

Influence of Microstructure on High-Cycle Fatigue of Ti-6Al-4V: Bimodal vs. Lamellar Structures  

E-Print Network [OSTI]

for such failures in Ti-6Al-4V, a commonly used turbine blade alloy, specifically for fan and compressor blades.K. NALLA, B.L. BOYCE, J.P. CAMPBELL, J.O. PETERS, and R.O. RITCHIE The high-cycle fatigue (HCF) of titanium] HCF can result in essentially unpredictable used for blade and disk applications in the front (low

Ritchie, Robert

460

The French design code: RCC-M status and on-going developments  

SciTech Connect (OSTI)

Since 1978, an important effort has been on-going between Framatome and Electricite de France (EDF) to develop and update technical rules for the design and construction of nuclear power plants. Two design codes are developed, one for PWRs: RCC-M and one for FBRs: RCC-MR. After some comments on the organization of RCCM Commission, the paper presents: (1) the major differences with the ASME Section III Code for fatigue, plastic shakedown and rupture analysis; (2) the review of some important facts in terms of availability or maintenance costs (in-service inspection, replacements, repairs, etc.) of operating plants like underclad cracking, stratification, CRDM nozzles, cast elbows, steam generator tubes, etc.; (3) how can one take into consideration this operating feedback in RCC-M Code; and (4) few examples of major on-going developments for fracture analysis on different components and fatigue analysis of valves. In conclusion, the standardization of the plants is a fruitful benefit because it allow inclusion of operating feedback in the design rules, earlier in the process of new designs or replacement parts.

Faidy, C. [Electricite de France-SEPTEN, Villeurbanne (France)

1996-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

2.72 Elements of Mechanical Design Spring 2014.v3 http://pcsl.mit.edu/2_72/index.html U-Level Lecture: MW 12.30-2.00 (35-122), Lab: M9-12 or M2-5 (25-122)  

E-Print Network [OSTI]

(Shigley/Mischke) Useful texts: Design of Machinery (Norton) Machinery's Handbook Ultimate GD&T Pocket: Lathes 03 2/12Shafts & ways: Deformation, stresses, modeling and integration 04 2/18Fatigue: Fundamentals and modeling methods GANTT chart M-lab 2: HTM [SS] 05 2/19Drives: Belt drives; types, forces, selection [AR] 06

Culpepper, Martin L.

462

MULTI-SCALE DIFFRACTION STUDY OF REVERSIBLE/IRREVERSIBLE DEFORMATION MECHANISMS IN THE NI-BASED SUPERALLOYS DURING FATIGUE  

SciTech Connect (OSTI)

In this study, a nickel-based polycrystalline is subjected to cyclic loading. The subsequent fatigue damage has been investigated with in-situ neutron-diffraction, thermal characterization for a single-phase, transmission-electron microscopy (TEM) and polychromatic X-ray microdiffraction (PXM). Different stages of fatigue damage are observed including bulk hardening, softening, and eventual saturation evident in the diffraction patterns and the thermal-evolution features. An increase in dislocation density is responsible for hardening within the early cycles. The transition to saturation cycles is characterized by the anisotropy of the lattice-strain evolution. Inhomogeneity of the thermal response and irreversible compression of the lattice planes and statistical dislocation structures are observed in the final saturation fatigue cycles. Analysis of the PXM-Laue patterns reveals cyclically-deformed microstructure near the grain boundaries, which are composed of the lattice rotations and grain subdivisions. The PXM results are in good agreement with the TEM results. Combined simulation/experimental analysis allows determination of slip-system dependent dislocation density in individual grains.

Barabash, Rozaliya [ORNL; Huang, E-Wen [ORNL; Clausen, Bjorn [ORNL; Liu, W. [Argonne National Laboratory (ANL); Ice, Gene E [ORNL; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2010-01-01T23:59:59.000Z

463

Microstructure Design of Low Alloy Transformation-Induced Plasticity Assisted Steels  

E-Print Network [OSTI]

................................................................ 91 7.2 Design of Intercritical Annealing ........................................................................... 95 7.3 Design of Bainitic Isothermal Transformation..................................................... 102 7.4 Resulting... followed by water quenching (red curve). The chemical composition of the sample is Fe-2.65Mn-0.95Si- 0.32C ................................................................................................................. 36 Figure 10...

Zhu, Ruixian

2013-03-20T23:59:59.000Z

464

Peak oil analyzed with a logistic function and idealized Hubbert curve  

Science Journals Connector (OSTI)

A logistic function is used to characterize peak and ultimate production of global crude oil and petroleum-derived liquid fuels. Annual oil production data were incrementally summed to construct a logistic curve in its initial phase. Using a curve-fitting approach, a population-growth logistic function was applied to complete the cumulative production curve. The simulated curve was then deconstructed into a set of annual oil production data producing an idealized Hubbert curve. An idealized Hubbert curve (IHC) is defined as having properties of production data resulting from a constant growth-rate under fixed resource limits. An IHC represents a potential production curve constructed from cumulative production data and provides a new perspective for estimating peak production periods and remaining resources. The IHC model data show that idealized peak oil production occurred in 2009 at 83.2Mb/d (30.4Gb/y). IHC simulations of truncated historical oil production data produced similar results and indicate that this methodology can be useful as a prediction tool.

Brian Gallagher

2011-01-01T23:59:59.000Z

465

Model Development to Establish Integrated Operational Rule Curves for Hungry Horse and Libby Reservoirs - Montana, 1996 Final Report.  

SciTech Connect (OSTI)

Hungry Horse and Libby dams have profoundly affected the aquatic ecosystems in two major tributaries of the Columbia River by altering habitat and water quality, and by imposing barriers to fish migration. In 1980, the U.S. Congress passed the Pacific Northwest Electric Power Planning and Conservation Act, designed in part to balance hydropower development with other natural resources in the Columbia System. The Act formed the Northwest Power Planning Council (Council) who developed a program to protect, mitigate and enhance fish and wildlife on the Columbia River and its tributaries. Pursuant to the Council`s Fish and Wildlife Program for the Columbia River System (1987), we constructed computer models to simulate the trophic dynamics of the reservoir biota as related to dam operation. Results were used to develop strategies to minimize impacts and enhance the reservoir and riverine fisheries, following program measures 903(a)(1-4) and 903(b)(1-5). Two FORTRAN simulation models were developed for Hungry Horse and Libby reservoirs located in northwestern Montana. The models were designed to generate accurate, short-term predictions specific to two reservoirs and are not directly applicable to other waters. The modeling strategy, however, is portable to other reservoir systems where sufficient data are available. Reservoir operation guidelines were developed to balance fisheries concerns in the headwaters with anadromous species recovery actions in the lower Columbia (Biological Rule Curves). These BRCs were then integrated with power production and flood control to reduce the economic impact of basin-wide fisheries recovery actions. These Integrated Rule Curves (IRCs) were developed simultaneously in the Columbia Basin System Operation Review (SOR), the Council`s phase IV amendment process and recovery actions associated with endangered Columbia Basin fish species.

Marotz, Brian; Althen, Craig; Gustafson, Daniel

1996-01-01T23:59:59.000Z

466

Multi-phase decline curve analysis with normalized rate and time  

E-Print Network [OSTI]

under certain wel lbore conditions in a certain shaped reservoir (eg. a fractured well in a 2xl rectangle). Fetkovich (1980) presented a type curve for decline curve analys~s of we 1 ls in a radial reservoir, He combined the analytical solution... for radial flow from a finite wellbore in a finite reservoir with the Arps decline curves using 'b' values ranging from 0 to 1. Fetkovich gt al. (1984) presented case histories to suggest possible 'b' values for different reservoir conditions including two...

Fraim, Michael Lee

1988-01-01T23:59:59.000Z

467

The effect of meaningfulness on the shape of the serial position curve  

E-Print Network [OSTI]

to test the hypothesis that the controlling stimulus in serial learning is the position an item occupies in a serial list, and therefore the shape of the serial position curve is invariant. This hypothesis was tested by stratifying meaningfulness... in the tails. List 3, the control list, consisted of a randomly generated sequence of the same words in lists 1 and 2. It was hypothesized that if meaningfulness could affect the shape of the serial position curve, then the learning curve for list 1 would...

Edwards, Mark Lee

1970-01-01T23:59:59.000Z

468

Energy Injection Episodes in Gamma Ray Bursts: The Light Curves and Polarization Properties of GRB 021004  

E-Print Network [OSTI]

Several GRB afterglow light curves deviate strongly from the power law decay observed in most bursts. We show that these variations can be accounted for by including refreshed shocks in the standard fireball model previously used to interpret the overall afterglow behavior. As an example we consider GRB 021004 that exhibited strong light curve variations and has a reasonably well time-resolved polarimetry. We show that the light curves in the R-band, X-rays and in the radio can be accounted for by four energy injection episodes in addition to the initial event. The polarization variations are shown to be a consequence of the injections.

G. Bjornsson; E. H. Gudmundsson; G. Johannesson

2004-09-24T23:59:59.000Z

469

Design Editorial A Design Societies Federation  

E-Print Network [OSTI]

Journal of Mechanical Design Editorial A Design Societies Federation You can recognize the many faces of design by looking at the many different professional societies that promote design around the world. These societies may have roots in engineering or archi- tecture or industrial design but they all

Papalambros, Panos

470

Pipeline ADC Design Methodology  

E-Print Network [OSTI]

Scaling vs. R. Figure 4.8 Pipeline ADC Structures. Figure2.4 A Pipelined ADC. Figure 3.1 Pipeline ADC Transfer Curve.Modes (b) data latency in pipeline ADC Figure 3.3 Detailed

Zhao, Hui

2012-01-01T23:59:59.000Z

471

Dynamic and Fatigue Analysis of an 18{sup th} Century Steel Arch Bridge  

SciTech Connect (OSTI)

Within the 'Oran-Tlemcen' railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer 'Gustave Eiffel' was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loads in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue.

Boumechra, Nadir [Department of Civil Engineering, Faculty of Engineering, University of Abou Bekr Belkaid, Chetouane B.P. 230, 13000, Tlemcen (Algeria); Hamdaoui, Karim [Department of Structural Mechanics, University of Pavia, Via Ferrata 1, 27100, Pavia (Italy)

2008-07-08T23:59:59.000Z

472

Rolling contact fatigue in high vacuum using ion plated nickel-copper-silver solid lubrication  

SciTech Connect (OSTI)

Ion plated, nickel-copper-silver coated steel ball bearings that were tested in rolling contact fatigue (RCF) experiments in high vacuum are presented in this article. ANSI T5 ball bearings were coated with approximately 10 nm of nickel-copper followed by 100 nm of silver using a dc ion plating process. The balls were then tested for RCF in vacuum in the 10{sup -7} Torr range at 130 Hz rotational speed and at 4.1 GPa Hertzian contact stress. The significance of this work is in the extension of RCF testing to an ultrahigh vacuum (UHV) application using silver as a lubricant instead of oil. The effects of pressure and voltage on the ion plating process were also investigated using scanning electron microscopy and RCF life testing in UHV. Test results with a ball size of 5/16 in. in UHV show that deposition at voltages greater than 2.5 kV shortens the RCF life and introduces a unique failure mode. Voltage and pressure fluctuations during the deposition process result in significant thickness monitor measurement errors as well. A regulator control scheme that minimizes the process pressure overshoot is also simulated.

Danyluk, Mike; Dhingra, Anoop [Mechanical Engineering Department, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211-3029 (United States)

2011-01-15T23:59:59.000Z

473

Abstract--A recent approach to steerable needle design is based on combining pre-curved tubes concentrically. By  

E-Print Network [OSTI]

or through a body orifice. Once inside the lumen, the proximal portion can remain relatively fixed while behavior. Real-time control necessitates balancing accuracy of the model with efficiency of its computation

Dupont, Pierre

474

IEEE TRANSACTIONS ON MAGNETICS, VOL. 43, NO. 2, FEBRUARY 2007 721 Design Curves and Information-Theoretic Limits  

E-Print Network [OSTI]

-squared error (MMSE) equalizer, a Viterbi detector, and a Reed­Solomon (RS) code. Our main conclusion et al. [1] proposed a quasi-analytical methodology to optimize the system for a channel model-squared error (MMSE) equalizer, a maximum-likelihood detector, and a Reed­Solomon (RS) error-correcting code

Siegel, Paul H.

475

Climate Change Adaptation: Getting Ahead of the Curve1 Alexis Saba, Michela Biasutti, Michael B. Gerrard,*  

E-Print Network [OSTI]

climate change adaptation in developing countries. Other sources of financing, from multilateral GEF: Global Environment Facility IPCC: Intergovernmental Panel on Climate Change LDCs: Least Developed! 1 ! Climate Change Adaptation: Getting Ahead of the Curve1 Alexis Saba, Michela Biasutti, Michael

Biasutti, Michela

476

Loop Variables and the Interacting Open String in a Curved Background  

E-Print Network [OSTI]

Applying the loop variable proposal to a sigma model (with boundary) in a curved target space, we give a systematic method for writing the gauge and generally covariant interacting equations of motion for the modes of the open string in a curved background. As in the free case described in an earlier paper, the equations are obtained by covariantizing the flat space (gauge invariant) interacting equations and then demanding gauge invariance in the curved background. The resulting equation has the form of a sum of terms that would individually be gauge invariant in flat space or at zero interaction strength, but mix amongst themselves in curved space when interactions are turned on. The new feature is that the loop variables are deformed so that there is a mixing of modes. Unlike the free case, the equations are coupled, and all the modes of the open string are required for gauge invariance.

B. Sathiapalan

2005-03-01T23:59:59.000Z

477

Interplay of oxygen-evolution kinetics and photovoltaic power curves on the construction of artificial leaves  

E-Print Network [OSTI]

An artificial leaf can perform direct solar-to-fuels conversion. The construction of an efficient artificial leaf or other photovoltaic (PV)-photoelectrochemical device requires that the power curve of the PV material and ...

Surendranath, Yogesh

478

SLOPE ESTIMATES OF ARTIN-SCHREIER CURVES JASPER SCHOLTEN AND HUI JUNE ZHU  

E-Print Network [OSTI]

SLOPE ESTIMATES OF ARTIN-SCHREIER CURVES JASPER SCHOLTEN AND HUI JUNE ZHU Abstract. Let X polygon, zeta and L functions over finite fields. 1 #12;2 JASPER SCHOLTEN AND HUI JUNE ZHU b) If p > 2d

Zhu, Hui June

479

Dynamics of Curved Detonation Front and Critical Conditions for Detonation Initiations  

Science Journals Connector (OSTI)

The curved detonation front appears in a number of unsteady phenomena such as the diffraction of detonations, the initiation of detonation by a point energy source, by a ... propagating velocity D and the curvatu...

L. He

1997-01-01T23:59:59.000Z

480

Real space mapping of oxygen vacancy diffusion and electrochemical transformations by hysteretic current reversal curve measurements  

SciTech Connect (OSTI)

An excitation voltage biases an ionic conducting material sample over a nanoscale grid. The bias sweeps a modulated voltage with increasing maximal amplitudes. A current response is measured at grid locations. Current response reversal curves are mapped over maximal amplitudes of the bias cycles. Reversal curves are averaged over the grid for each bias cycle and mapped over maximal bias amplitudes for each bias cycle. Average reversal curve areas are mapped over maximal amplitudes of the bias cycles. Thresholds are determined for onset and ending of electrochemical activity. A predetermined number of bias sweeps may vary in frequency where each sweep has a constant number of cycles and reversal response curves may indicate ionic diffusion kinetics.

Kalinin, Sergei V.; Balke, Nina; Borisevich, Albina Y.; Jesse, Stephen; Maksymovych, Petro; Kim, Yunseok; Strelcov, Evgheni

2014-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "fatigue design curves" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Supplement and optimization of classical capillary number experimental curve for enhanced oil recovery by combination flooding  

Science Journals Connector (OSTI)

In the middle of the last century, American scientists put forward the concept of capillary number and obtained the relation curve between capillary number and residual oil through experiments. They revealed t...

LianQing Qi; ZongZhao Liu; ChengZhi Yang

2014-10-01T23:59:59.000Z

482

A discrete L-curve for the regularization of ill-posed inverse problems  

E-Print Network [OSTI]

May 23, 2012 ... The L-curve criterium is a popular tool for choosing good regularized solutions, when the data noise norm is not a priori known. In this work, we...

Germana Landi

2012-05-23T23:59:59.000Z

483

Applying Decline Curve Analysis in the Liquid-rich Shales: Eagle Ford Shale Study  

E-Print Network [OSTI]

of data from unconventional oil wells flowing under unstable operating conditions. Fetkovich (hydraulically fractured well) type curve analysis can be added to improve confidence in flow regime identification from diagnostic plots and to estimate the Arps...

Indras, Purvi

2014-01-09T23:59:59.000Z

484

On isogeny classes of Edwards curves over finite fields Omran Ahmadi Robert Granger  

E-Print Network [OSTI]

.ahmadi@ucd.ie rgranger@computing.dcu.ie Claude Shannon Institute University College Dublin Dublin 4 Ireland March 17, 2011 Abstract We count the number of isogeny classes of Edwards curves over finite fields, answering

485

Full Automation of Infrared Qualitative Analysis of Binary Mixtures by Use of a Spectral Curve Compilation  

Science Journals Connector (OSTI)

A project for the compilation of infrared spectral curves is now in progress at the National Chemical Laboratory for Industry, Japan. On the basis of this compilation, a computer...

Saki, Shinnosuke; Tanabe, Kazutoshi

1984-01-01T23:59:59.000Z

486

Nondestructive method and apparatus for imaging grains in curved surfaces of polycrystalline articles  

DOE Patents [OSTI]

A nondestructive method, and associated apparatus, are provided for determining the grain flow of the grains in a convex curved, textured polycrystalline surface. The convex, curved surface of a polycrystalline article is aligned in a horizontal x-ray diffractometer and a monochromatic, converging x-ray beam is directed onto the curved surface of the polycrystalline article so that the converging x-ray beam is diffracted by crystallographic planes of the grains in the polycrystalline article. The diffracted x-ray beam is caused to pass through a set of horizontal, parallel slits to limit the height of the beam and thereafter. The linear intensity of the diffracted x-ray is measured, using a linear position sensitive proportional counter, as a function of position in a direction orthogonal to the counter so as to generate two dimensional data. An image of the grains in the curved surface of the polycrystalline article is provided based on the two-dimensional data.

Carpenter, Donald A. (Lenior City, TN)

1995-01-01T23:59:59.000Z

487

Evaluation of corrosion rate from polarisation curves not exhibiting a Tafel region  

Science Journals Connector (OSTI)

Evaluation of corrosion rate by Tafel extrapolation is often impossible, simply because an experimental polarisation curve does not exhibit linear Tafel regions. This paper shows how such curves for the Fe/H2O/H+/O2 corrosion system can be accurately deconstructed to furnish both kinetic and thermodynamic parameters for the anodic and cathodic reactions. The curved anodic branch (due to film formation) is then amenable to correction for IR voltage drop and the resulting Tafel slope and other parameters are then substituted in the Tafel equation to accurately determine icorr. An alternative method to obtain the anodic Tafel slope has been used to validate the above approach. Polarisation curves describing the inhibition of mild steel in industrial cooling water were scanned/digitised from the literature.

Harvey J. Flitt; D. Paul Schweinsberg

2005-01-01T23:59:59.000Z

488

Efficient Estimation of the Lorenz Curve and Associated Inequality Measures from Grouped Observations  

Science Journals Connector (OSTI)

This paper introduces a new coordinate system for the Lorenz curve. Particular attention is paid to a special case of wide empirical validity. Four alternative methods have been used to estimate the proposed L...

N. C. Kakwani; N. Podder

2008-01-01T23:59:59.000Z

489

Interrelation Between the Accuracy of Prediction and Irregularity of Electric Energy Demand Curves  

Science Journals Connector (OSTI)

Results of a study of the dependence of the accuracy of prediction on daily and seasonal irregularity of demand curves are described. It is shown that in power systems characterized by high irregularity of the...

B. I. Makoklyuev; V. F. Ech

490

3D Curves With a Prescribed Curvature and Torsion for a Flying Robot  

SciTech Connect (OSTI)

The objective of this paper is to generate a desired flight path to be followed by an flying robot. A curve with discontinuous curvature and torsion is not appropriate for smooth motions for any vehicle architecture. Three different classes of curves are presented. First, constant curvature and torsion followed by a linear variation versus the curvilinear abscissa then a quadratic variation. Finally, the problem of maneuvers between two trim helices of different curvature and torsion is tackled with.

Bestaoui, Yasmina [Informatics, Integrative Biology and Complex Systems, University of Evry 40 Rue de Pelvoux, 91020 Evry Cedex (France)

2008-06-12T23:59:59.000Z

491

A shear deformable, doubly curved finite element for the analysis of laminated composite structures  

E-Print Network [OSTI]

A SHL'AR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Submitted to the Graduate College of Texas AE-M University in partial fulfiHment of the requirement... for the degree of MASTER OF SCIENCE May 1988 Major Subject: Mechanical Engineering A SHEAR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Approved as to style and content by...

Fuehne, Joseph Patrick

2012-06-07T23:59:59.000Z

492

Analysis and forecasting of gas well performanc: a rigorous approach using decline curve analysis  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3. 1. 2 Analytical Decline Curve Developments. . . . . . . . . . . . . . . . . . . . . . . . 19 3. 1. 2. 1 Development of the Exponential Decline Using van Everdingen and Hurst Approach. . . . . . . . . . . . . . . . . 19 3. 1. 2. 2 Fetkovich... Pressure Profile . 66 4. 5 Constant Pressure Equivalent Analysis Using the Fetkovich Type Curve for Variable Rate/Variable Pressure Dmp Flow Data. 73 76 77 80 4. 6 CHAPIXR V 83 83 84 86 86 88 90 90 96 5. 1 5. 2 Verification of Gas Flow...

Palacio Uran, Juan Carlos

1993-01-01T23:59:59.000Z

493

Math 172 Chapter 7A notes Page 1 of 14 7.1 Area Between Curves  

E-Print Network [OSTI]

= 1 5 (1)5 - 1 5 (-1)51 -1 = 1 5 (1) - 1 5 (-1) = 2 5 = 2 - 2 5 = 8 5 Example. Find the areaMath 172 Chapter 7A notes Page 1 of 14 7.1 Area Between Curves Recall area under a curve graph in [, ] = - Choose sample points in each subinterval. Add sample point in and draw rectangle 1 , ... , Area

Schumaker, Mark

494

Caloric Curves for small systems in the Nuclear Lattice Gas Model  

E-Print Network [OSTI]

For pedagogical reasons we compute the caloric curve for 11 particles in a $3^3$ lattice. Monte-Carlo simulation can be avoided and exact results are obtained. There is no back-bending in the caloric curve and negative specific heat does not appear. We point out that the introduction of kinetic energy in the nuclear Lattice Gas Model modifies the results of the standard Lattice Gas Model in a profound way.

C. B. Das; S. Das Gupta

2000-09-27T23:59:59.000Z

495

A New Type Curve Analysis for Shale Gas/Oil Reservoir Production Performance with Dual Porosity Linear System  

E-Print Network [OSTI]

matching program.................. ...................... 46 6.2 Synthetic case generated with Stehfest to test the accuracy of the type curve shape................... ........................................................................... 47... 6.3 Synthetic case generated with CMG to test the accuracy of type curve results which show very close values.................... ................................ 48 6.4 Synthetic case generated with CMG to test the accuracy of type curve...

Abdulal, Haider Jaffar

2012-02-14T23:59:59.000Z

496

Inflow performance relationship curves in two-phase and three-phase flow conditions  

SciTech Connect (OSTI)

This research investigates inflow performance relationship IPR curves for two and three-phase flow conditions, using a one-dimensional, three-phase cylindrical reservoir simulator. Using the simulator, a new method for predicting future IPR curves was developed. IPR curves for two-phase flow conditions from a well producing from low permeability formations are also presented. The purpose of this investigation is to predict the IPR curves at pseudo-steady state conditions using flowing test data obtained during the transient period. The new equations have also been applied to data from the simulator with good agreement. Three-phase IPR curves are also determined by using the simulator, and seven different hypothetical three-phase reservoir cases were studied. Three-hundred and eighty five data points were collected using 5 different values of water cut. Regression analysis techniques were applied to the data points and the new equations for predicting the three-phase IPR curves were developed. Comparison of the new equations to results from the simulator show excellent agreement.

Sukarno, P.

1986-01-01T23:59:59.000Z

497

New model adds precision to gas-lift design  

SciTech Connect (OSTI)

Conoco Inc.'s new analytical technique for lift-gas allocation identifies, in one-pass, injection rates and the achievable mandrel location for injection. Current gas-lift allocation techniques do not determine production rates for discrete mandrel locations. Allocation rates for particular wells are made on the basis of a fixed differential pressure. When actual mandrel locations are superimposed on these solutions, gas often must be reallocated. The advantages of the new technique include: determining the transfer capability of the gas-lift valve in each mandrel; finding valve pressure drop as a function of injection gas rate; obtaining a more realistic response curve. Another potential benefit is that the response curve can be adjusted to reflect the water cut and/or multizone completion effects at different injection depths. Because the node is at the mandrel, the inflow performance relationship (IPR) at that depth can easily be adjusted to include such effects. The paper describes gas-lift applications; response curves; injection depth; field-wide curves; the mandrel curve; and valve design.

Kendrick, R.A. (Hampton Resources Inc., Houston, TX (United States)); Woodyard, A.H.; Hall, J.W. (Conoco Inc., Houston, TX (United States))

1993-05-03T23:59:59.000Z

498

Prediction of the Fatigue Life of Cast Steel Containing Shrinkage Porosity  

E-Print Network [OSTI]

of porosity becomes especially critical. An integrated design process is emerging in which a casting process] It is anticipated that such a design process will also help guide and improve casting inspection procedures INHOMOGENEITIES due to porosity are currently not considered in the design of structural components made from

Beckermann, Christoph

499

Design wiki: a system for design sharing  

E-Print Network [OSTI]

Design wiki: a system for design sharing Wael A. Abdelhameed, Yoshihiro Kobayashi #12;Wael of Bahrain. His research areas are 3D Modeling Systems, Computing Architecture, Virtual Reality, Design Process, Visual Design Thinking and Digital and Manual Media Interaction. Yoshihiro Kobayashi is a Faculty

500

Institute of Design Institute of Design  

E-Print Network [OSTI]

Institute of Design Institute of Design 350 N. LaSalle St. Chicago, IL 60610 312.595.4900 main 312.595.4906 graduate study information 312.595.4901 fax design@id.iit.edu www.id.iit.edu Dean: Patrick F. Whitney The Institute of Design (ID) is defined by a legacy of experimentation joined with unique academic programs

Heller, Barbara