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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
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1

Review of the margins for ASME code fatigue design curve - effects of surface roughness and material variability.  

SciTech Connect (OSTI)

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. The Code specifies 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 the existing fatigue {var_epsilon}-N data for carbon and low-alloy steels and wrought and cast austenitic SSs to define the effects of key material, loading, and environmental parameters on the fatigue lives of the steels. Experimental data are presented on the effects of surface roughness on the fatigue life of these steels in air and LWR environments. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are discussed. Data available in the literature have been reviewed to evaluate the conservatism in the existing ASME Code fatigue evaluations. A critical review of the margins for ASME Code fatigue design curves is presented.

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

2003-10-03T23:59:59.000Z

2

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...

3

FATIGUE DESIGN CURVES FOR  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicy andExsolution Enhanced OilExtracting theExtremeMtoActTWOFATIGUE

4

Application of NUREG/CR-5999 interim fatigue curves to selected nuclear power plant components  

SciTech Connect (OSTI)

Recent test data indicate that the effects of the light water reactor (LWR) environment could significantly reduce the fatigue resistance of materials used in the reactor coolant pressure boundary components of operating nuclear power plants. Argonne National Laboratory has developed interim fatigue curves based on test data simulating LWR conditions, and published them in NUREG/CR-5999. In order to assess the significance of these interim fatigue curves, fatigue evaluations of a sample of the components in the reactor coolant pressure boundary of LWRs were performed. The sample consists of components from facilities designed by each of the four U.S. nuclear steam supply system vendors. For each facility, six locations were studied, including two locations on the reactor pressure vessel. In addition, there are older vintage plants where components of the reactor coolant pressure boundary were designed to codes that did not require an explicit fatigue analysis of the components. In order to assess the fatigue resistance of the older vintage plants, an evaluation was also conducted on selected components of three of these plants. This report discusses the insights gained from the application of the interim fatigue curves to components of seven operating nuclear power plants.

Ware, A.G.; Morton, D.K.; Nitzel, M.E. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1995-03-01T23:59:59.000Z

5

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

E-Print Network [OSTI]

Fatigue threshold R-curves for predicting reliability of ceramics under cyclic loading J.J. Kruzic for the prediction of reliability in bridging ceramics under cyclic loading conditions based on a fatigue threshold R-curve threshold R-curve may express this crack-size dependence, analogous to the traditional fracture toughness R-curve

Ritchie, Robert

6

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

7

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

8

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

9

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

10

MECH 491 Mechanical Engineering Design I -Project Description Project Topic: A corrosion fatigue experiment setup design  

E-Print Network [OSTI]

Topic: A deformation setup design for testing of small scale metallic materials Project DescriptionProject 1 MECH 491 ­ Mechanical Engineering Design I - Project Description Project Topic: A corrosion fatigue experiment setup design Project Description: It is required for the students to design

Muradoglu, Metin

11

Presented at 1999 EWEC Effects of Materials Parameters and Design Details on the Fatigue of  

E-Print Network [OSTI]

of Composite Materials for Wind Turbine Blades John F. Mandell and Herbert J. Sutherland* Daniel D. SamborskyPresented at 1999 EWEC Effects of Materials Parameters and Design Details on the Fatigue Wind Energy Technology Dept. Dept. of Chemical Engineering Sandia National Laboratories Montana State

12

GUIDELINES FOR DESIGN AND SAFE HANDLING OF CURVED I-SHAPED STEEL GIRDERS  

E-Print Network [OSTI]

0-5574-P1 GUIDELINES FOR DESIGN AND SAFE HANDLING OF CURVED I-SHAPED STEEL GIRDERS Authors: Jason FOR DESIGN AND SAFE HANDLING OF CURVED I-SHAPED STEEL GIRDERS PURPOSE: The purpose of this set of guidelines-sixth #12;2 (Eq. 6.10.2.2-2). However, TxDOT's Preferred Practices for Steel Bridge Design, Fabrication

Texas at Austin, University of

13

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

14

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

15

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

16

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...

17

A Scan-based Attack on Elliptic Curve Cryptosystems in presence of Industrial Design-for-Testability Structures  

E-Print Network [OSTI]

A Scan-based Attack on Elliptic Curve Cryptosystems in presence of Industrial Design-based attack on hardware implementations of Elliptic Curve Cryptosystems (ECC). Several up-to-date Design aspects of the proposed scan-based attack are described, namely timing and leakage analysis that allows

Paris-Sud XI, Université de

18

An Energy Based Fatigue Life Prediction Framework for In-Service Structural Components  

SciTech Connect (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 the life prediction framework is to account aging effect caused by cyclic loadings on fatigue strength of gas turbine engines structural components which are usually designed for very long life. Previous studies indicate the total strain energy dissipated during a monotonic fracture process and a cyclic process is a material property that can be determined by measuring the area underneath the monotonic true stress-strain curve and the sum of the area within each hysteresis loop in the cyclic process, respectively. The energy-based fatigue life prediction framework consists of the following entities: (1) development of a testing procedure to achieve plastic energy dissipation per life cycle and (2) incorporation of an energy-based fatigue life calculation scheme to determine the remaining fatigue life of in-service gas turbine materials. The accuracy of the remaining fatigue life prediction method was verified by comparison between model approximation and experimental results of Aluminum 6061-T6. The comparison shows promising agreement, thus validating the capability of the framework to produce accurate fatigue life prediction.

H. Ozaltun; M. H.H. Shen; T. George; C. Cross

2011-06-01T23:59:59.000Z

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

Design, build and test of an axial flow hydrokinetic turbine with fatigue analysis  

E-Print Network [OSTI]

OpenProp is an open source propeller and turbine design and analysis code that has been in development since 2007 by MIT graduate students under the supervision of Professor Richard Kimball. In order to test the performance ...

Ketcham, Jerod W

2010-01-01T23:59:59.000Z

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.


21

The concrete road : development and present status of design and construction  

E-Print Network [OSTI]

of Temperature and Trafiic 21 2. Impact 2? 3. Fatigue of Concrete C. Design of Concrete Pavements 44 1. Cross-Sections of Concrete Slabs 45 2. Stresses in Concrete Pavements - Thick ness of Slab 5o 3. Defects in Concrete Pavement Slabs - Con trol... 36 * 12. Static Loading Curve. Fatigue Test Method .. 38 " 13. Fatigue Endurance -^irnit of Cement Mortar Beams 39 * 14. Effect of prolonged Rest Period 4o 15. Effect of Increasing the Load during Fatigue Action 42 16. Typical Cross...

Puell, Heinz Werner

1935-01-01T23:59:59.000Z

22

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

23

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

E-Print Network [OSTI]

documents an evaluation of the effects of superelevation on operating speeds and accident experience and the effects of side friction demand on accident experience at horizontal curves on rural two-lane highways. Variables considered in operating speed.... The hypothesis of this portion of the study was that the addition of superelevation would cause operating speeds to increase. Superelevation was found to have a significant influence on vehicle operating speeds. Potential accident surrogates examined included...

Voigt, Anthony Paul

1995-01-01T23:59:59.000Z

24

A Fatigue Approach to Wind Turbine Control  

E-Print Network [OSTI]

A Fatigue Approach to Wind Turbine Control Keld Hammerum Kongens Lyngby 2006 #12;Technical to the turbulent nature of wind, the structural components of a wind turbine are exposed to highly varying loads. Therefore, fatigue damage is a major consideration when designing wind turbines. The control scheme applied

25

Development of Yield and Tensile Strength Design Curves for Alloy 617  

SciTech Connect (OSTI)

The U.S. Department of Energy Very High Temperature Reactor Program is acquiring data in preparation for developing an Alloy 617 Code Case for inclusion in the nuclear section of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code. A draft code case was previously developed, but effort was suspended before acceptance by ASME. As part of the draft code case effort, a database was compiled of yield and tensile strength data from tests performed in air. Yield strength and tensile strength at temperature are used to set time independent allowable stress for construction materials in B&PV Code, Section III, Subsection NH. The yield and tensile strength data used for the draft code case has been augmented with additional data generated by Idaho National Laboratory and Oak Ridge National Laboratory in the U.S. and CEA in France. The standard ASME Section II procedure for generating yield and tensile strength at temperature is presented, along with alternate methods that accommodate the change in temperature trends seen at high temperatures, resulting in a more consistent design margin over the temperature range of interest.

Nancy Lybeck; T. -L. Sham

2013-10-01T23:59:59.000Z

26

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

27

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

28

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

29

Final Report on In-Reactor Creep-Fatigue Deformation Behaviour of a  

E-Print Network [OSTI]

-fatigue cyclic loading directly in a fission reactor. Using specially designed test facilities for this purpose temperatures of 326K and 323K. For comparison purposes corresponding out-of-reactor creep-fatigue tests wereFinal Report on In-Reactor Creep- Fatigue Deformation Behaviour of a CuCrZr Alloy: COFAT 2 B

30

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

31

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

32

Drag amplification and fatigue damage in vortex-induced vibrations  

E-Print Network [OSTI]

Fatigue damage and drag force amplification due to Vortex-Induced-Vibrations (VIV) continue to cause significant problems in the design of structures which operate in ocean current environments. These problems are magnified ...

Jhingran, Vikas Gopal

2008-01-01T23:59:59.000Z

33

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

34

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

#12;Flow Duration Curve Load Duration Curve #12;1. Develop Flow Duration Curve 2. Estimate load 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;Describes

35

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

Flow Duration Curve Load Duration Curve 1. Develop Flow Duration Curve 2. Estimate load given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve What are they? How do you make one? Describes the percent of time a flow rate

36

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

37

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

38

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

39

Ris-R-1168 (EN) Fatigue damage development  

E-Print Network [OSTI]

blades for wind turbines, for instance, hybrid designs with glass/carbon fibre reinforced plastics/carbon fibre hybrid laminates Olivia Redon Materials Research Department Ris National Laboratory, Roskilde are under consideration as the blades are getting larger than 30-40 metres. The tensile fatigue behaviour

40

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

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

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

42

Human Muscle Fatigue Model in Dynamic Motions  

E-Print Network [OSTI]

Human Muscle Fatigue Model in Dynamic Motions Ruina Ma, Damien Chablat, Fouad Bennis, and Liang Ma Abstract Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main

Boyer, Edmond

43

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

44

Effect of fiber fabric orientation on the monotonic and fatigue behavior of a continuous fiber ceramic composite  

SciTech Connect (OSTI)

The monotonic fast fracture and fatigue behavior of a Nextel{trademark} 312 reinforced SiC matrix composite was investigated. Effect of fabric orientation with respect to the loading axis on the monotonic and fatigue behavior of the composite was examined. Two geometries were investigated: transverse, where fiber fabric is perpendicular to loading direction; and edge-on where the fabric is parallel to the loading axis. The edge-on geometry showed higher flexure strengths than the transverse orientation. The different deformation mechanisms between the edge-on and transverse orientations were due to strong in-plane shearing of the fiber fabric and weak interlaminar shear of the plies, respectively. In cyclic fatigue, stress versus cycles (S-N) curves showed high fatigue endurance limits in both orientations, although the transverse orientation survived more cycles than the edge-on orientation at stresses slightly above the endurance limit.

Chawla, N.; Liaw, P.K. [Tennessee Univ., Knoxville, TN (United States). Dept. of Materials Science and Engineering; Lara-Curzio, E.; Lowden, R.A.; Ferber, M.K. [Oak Ridge National Lab., TN (United States)

1994-09-01T23:59:59.000Z

45

FRACTURE MECHANICS APPROACH TO ESTIMATE FATIGUE LIVES OF WELDED LAP-SHEAR SPECIMENS  

SciTech Connect (OSTI)

A full range of stress intensity factor solutions for a kinked crack is developed as a function of weld width and the sheet thickness. When used with the associated main crack solutions (global stress intensity factors) in terms of the applied load and specimen geometry, the fatigue lives can be estimated for the laser-welded lap-shear specimens. The estimations are in good agreement with the experimental data. A classical solution for an infinitesimal kink is also employed in the approach. However, the life predictions tend to overestimate the actual fatigue lives. The traditional life estimations with the structural stress along with the experimental stress-fatigue life data (S-N curve) are also provided. In this case, the estimations only agree with the experimental data under higher load conditions.

Lam, P.; Michigan, J.

2014-04-25T23:59:59.000Z

46

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

E-Print Network [OSTI]

Stress 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 cedex, France Abstract Drill pipe in a curved section of the drilled well is considered as a rotating

Paris-Sud XI, Université de

47

Investigation of learning and experience curves  

SciTech Connect (OSTI)

The applicability of learning and experience curves for predicting future costs of solar technologies is assessed, and the major test case is the production economics of heliostats. Alternative methods for estimating cost reductions in systems manufacture are discussed, and procedures for using learning and experience curves to predict costs are outlined. Because adequate production data often do not exist, production histories of analogous products/processes are analyzed and learning and aggregated cost curves for these surrogates estimated. If the surrogate learning curves apply, they can be used to estimate solar technology costs. The steps involved in generating these cost estimates are given. Second-generation glass-steel and inflated-bubble heliostat design concepts, developed by MDAC and GE, respectively, are described; a costing scenario for 25,000 units/yr is detailed; surrogates for cost analysis are chosen; learning and aggregate cost curves are estimated; and aggregate cost curves for the GE and MDAC designs are estimated. However, an approach that combines a neoclassical production function with a learning-by-doing hypothesis is needed to yield a cost relation compatible with the historical learning curve and the traditional cost function of economic theory.

Krawiec, F.; Thornton, J.; Edesess, M.

1980-04-01T23:59:59.000Z

48

Simultaneous confidence bands in curve prediction applied to load curves  

E-Print Network [OSTI]

Simultaneous confidence bands in curve prediction applied to load curves J.M. Azais1, S. Bercu2, J, load curve. 1 Introduction In curve prediction, one is generally interested in deriving simultaneous this technique in the numerical context of load curve pre- diction: power producers like EDF, the electrical

Boyer, Edmond

49

Crude oil supply curves  

E-Print Network [OSTI]

Short-run cost curves shift over time as depletion counters increasing knowledge. Under competition, a rightward (leftward) shift indicates lower (higher) cost and greater (lesser) productivity. A simple coefficient captures ...

Adelman, Morris Albert

1998-01-01T23:59:59.000Z

50

Seismic fragility curves for reinforced concrete A Dissertation Submitted in Partial Fulfilment of the Requirements  

E-Print Network [OSTI]

Seismic fragility curves for reinforced concrete buildings A Dissertation Submitted in Partial dissertation entitled "Seismic fragility curves for reinforced concrete frame and wall- frame buildings. Buildings designed for seismic loading, and buildings designed only for gravity loads, are considered

51

: runout specimen max : maximum fatigue stress  

E-Print Network [OSTI]

High Performance Fibre Reinforced Concrete (UHPFRC) layer to concrete bridge deck slab was conceived was drawn without runout specimens .) Figure 6 Fatigue fracture surface of (a) UHPFRC, (b) steel rebar (a influenced by fibre distribution and orientation. Fatigue fracture surface of UHPFRC is similar

52

Prediction of the Creep-Fatigue Lifetime of Alloy 617: An Application of Non-destructive Evaluation and Information Integration  

SciTech Connect (OSTI)

A relatively simple method using the nominal constant average stress information and the creep rupture model is developed to predict the creep-fatigue lifetime of Alloy 617, in terms of time to rupture. The nominal constant average stress is computed using the stress relaxation curve. The predicted time to rupture can be converted to number of cycles to failure using the strain range, the strain rate during each cycle, and the hold time information. The predicted creep-fatigue lifetime is validated against the experimental measurements of the creep-fatigue lifetime collected using conventional laboratory creep-fatigue tests. High temperature creep-fatigue tests of Alloy 617 were conducted in air at 950C with a tensile hold period of up to 1800s in a cycle at total strain ranges of 0.3% and 0.6%. It was observed that the proposed method is conservative in that the predicted lifetime is less than the experimentally determined values. The approach would be relevant to calculate the remaining useful life to a component like a steam generator that might fail by the creep-fatigue mechanism.

Vivek Agarwal; Richard Wright; Timothy Roney

2014-08-01T23:59:59.000Z

53

Modeling Thermal Fatigue in CPV Cell Assemblies (Presentation)  

SciTech Connect (OSTI)

This presentation outlines the modeling of thermal fatigue in concentrating photovoltaic (CPV) assemblies.

Bosco, N.; Panchagade, D.; Kurtz, S.

2011-02-01T23:59:59.000Z

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

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

56

Extinction curves in AGN  

E-Print Network [OSTI]

The presence of the dust in the circumnuclear region strongly affects our view of the nucleus itself. The effect is strong in type 2 objects but weaker effect is likely to be present in type 1 objects as well. In these objects a correction to the observed optical/UV spectrum must be done in order to recover the intrinsic spectrum of a nucleus. The approach based on the extinction curve is convenient for that purpose so significant effort has been recently done in order to determine the extinction curve for the circumnuclear material. It seems clear that the circumnuclear dust is different from the average properties of the dust in the Interstellar Medium in our galaxy: the well known 2175 A feature is weak or absent in AGN nuclear dust, and the extinction curve at shorter wavelength does not seem to be rising as steeply. The circumnuclear dust is therefore more similar to SMC dust, or more likely, to the dust in very dense molecular clouds in our Galaxy. However, the exact shape of the extinction curve in the far UV is still a matter of debate, and various effects are difficult to disentangle.

B. Czerny

2006-12-16T23:59:59.000Z

57

Solder fatigue reduction in point focus photovoltaic concentrator modules  

SciTech Connect (OSTI)

Solder fatigue tests have been conducted on point focus photovoltaic concentration cell assemblies to identify a baseline fatigue life and to quantify the fatigue life improvements that result using a copper-molybdenum-copper low-expansion insert between the solar cell and copper heat spreader. Solder microstructural changes and fatigue crack growth were identified using cross sections and ultrasonic scans of the fatigue solder joints. The Coffin-Manson and Total Strain fatigue models for low-cycle fatigue were evaluated for use in fatigue life predictions. Since both of these models require strain calculations, two strain calculation methods were compared: hand-calculated shear strain and a finite element method shear strain. At present, the available theoretical models for low-cycle solder fatigue are limited in their ability to predict failure; consequently, extensive thermal cycling is continuing to define the fatigue life for point focus photovoltaic cell assemblies. 9 refs., 9 figs., 2 tabs.

Hund, T.D.; Burchett, S.N.

1991-01-01T23:59:59.000Z

58

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

59

A study of fatigue in drill collars  

E-Print Network [OSTI]

A STUDY OF FATIGUE IN DRILL COLLARS A Thesis by Joe Robert Feeler Approved as to style and content by: Chairman of Committee Head of Department Member /n/X~l~~ Member Member January 1969 ABSTRACT A Study of Fatigue in Drill Collars.... (January, 1969) Joe R. Fowler, B. S. , Texas A&M University; Directed by: Dr. P. D. Neiner Fatigue failures of drill collar connectors are presently cost- ing the major oil companies enormous sums of money in ruined equipment and lost time...

Fowler, Joe Robert

1969-01-01T23:59:59.000Z

60

Connecting curves for dynamical systems  

E-Print Network [OSTI]

We introduce one dimensional sets to help describe and constrain the integral curves of an $n$ dimensional dynamical system. These curves provide more information about the system than the zero-dimensional sets (fixed points) do. In fact, these curves pass through the fixed points. Connecting curves are introduced using two different but equivalent definitions, one from dynamical systems theory, the other from differential geometry. We describe how to compute these curves and illustrate their properties by showing the connecting curves for a number of dynamical systems.

R. Gilmore; Jean-Marc Ginoux; Timothy Jones; C. Letellier; U. S. Freitas

2010-03-08T23:59:59.000Z

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

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

62

Modelling the role of non metallic inclusions on the anisotropic fatigue behaviour of forged steel  

E-Print Network [OSTI]

reported as being 35% for 42CrMo4 steel [1] and 15% for a duplex stainless steel [2]. To design a forged steel E. Pessard* , F. Morel, A. Morel, D. Bellett LAMPA (EA1427) Arts et Métiers ParisTech Angers 2, Bd. This study aims at describing the high cycle fatigue response of a forged bainitic steel. This material

Paris-Sud XI, Université de

63

AIAA-2003-0692 NEW FATIGUE DATA FOR W IND TURBINE BLADE M ATERIALS  

E-Print Network [OSTI]

1 AIAA-2003-0692 NEW FATIGUE DATA FOR W IND TURBINE BLADE M ATERIALS John F. Mandell, Daniel D to the wind turbine industry in several areas: (a) very high cycle S-N data; (b) refined Goodman Diagram; (c the expected cycle range for turbines. While the data cannot be used directly in design due to the specialized

64

Dialogue essais-modle pour l'interprtation des liens entre mesure d'auto-chauffement sous chargement cyclique et fatigue polycyclique  

E-Print Network [OSTI]

by predicting S/N curves for different mean stress of a dual-phase steel. #12;3 1. INTRODUCTION La fatigue des courbes de Wöhler d'un acier dual-phase pour différents rapport de charge. Abstract

65

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

66

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

67

Fatigue failure in thin-film polysilicon is due to subcriticalcracking within the oxide layer  

SciTech Connect (OSTI)

It has been established that microelectromechanical systems (MEMS) created from polycrystalline silicon thin-films are subject to cyclic fatigue. Prior work by the authors has suggested that although bulk silicon is not susceptible to fatigue failure in ambient air, fatigue in micron-scale silicon is a result of a ''reaction-layer'' process, whereby high stresses induce a thickening of the post-release oxide at stress concentrations such as notches, which subsequently undergoes moisture-assisted cracking. However, there exists some controversy regarding the post-release oxide thickness of the samples used in the prior study. In this Letter, we present data from devices from a more recent fabrication run that confirm our prior observations. Additionally, new data from tests in high vacuum show that these devices do not fatigue when oxidation and moisture are suppressed. Each of these observations lends credence to the '''reaction-layer'' mechanism. Recent advances in the design of microelectromechanical systems (MEMS) have increased the demand for more reliable microscale structures. Although silicon is an effective and widely used structural material at the microscale, it is very brittle. Consequently, reliability is a limiting factor for commercial and defense applications. Since the surface to volume ratio of these structural films is very large, classical models for failure modes in bulk materials cannot always be applied. For example, whereas bulk silicon is immune to cyclic fatigue failure thin micron-scale structural films of silicon appear to be highly susceptible. It is clear that at these size scales, surface effects may become dominant in controlling mechanical properties. The main reliability issues for MEMS are stiction, fatigue and wear. Fatigue is important in cases where devices are subjected to a large number of loading cycles with amplitudes below their (single-cycle) fracture stress, which may arise due to vibrations intentionally induced in the structure (i.e. a resonator) or those which arise from the service environment. While the reliability of MEMS has received extensive attention, the physical mechanisms responsible for these failure modes have yet to be conclusively determined. This is particularly true for fatigue, where the mechanisms have been subject to intense debate. Recently we have proposed that the fatigue of micron-scale polysilicon is associated with stress-induced surface oxide thickening and moisture-assisted subcritical cracking in the amorphous SiO{sub 2} oxide layer (''reaction-layer'' fatigue). The mechanism of oxide thickening is as yet unknown, but is likely related to some form of stress-assisted diffusion. Allameh et al. suggest a complementary mechanism involving stress-assisted oxide thickening, caused by dissolution of the surface oxide which forms deep grooves that are sites for crack initiation. Kahn et al. have criticized these mechanisms and proposed that, instead, fatigue is caused by subcritical cracking due to contacting surface asperities in the compressive part of the cycle. To the authors' knowledge, there is no direct experimental observation of such asperity contact. Also, their model cannot explain why micron-scale silicon, and not bulk silicon, is susceptible to fatigue. Moreover, Kahn et al. do not acknowledge the role of stress-induced oxide thickening, which has been observed directly using TEM and indirectly using atomic-force microscope measurements by several investigators, and have questioned whether the materials utilized by Muhlstein et al. and Allameh et al. were representative due to the relatively thick oxide scales. Accordingly, the goal of the present research is to seek a definitive understanding of the physical mechanisms responsible for fatigue in polysilicon structural thin-films. Our approach is to combine on-chip testing methods with electron microscopy by fatiguing thin-film samples and observing them, in an unthinned condition, using high-voltage transmission electron microscopy (HVTEM). Two principal results are found from this work: (1

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

2005-01-11T23:59:59.000Z

68

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

69

Fatigue properties of die cast zinc alloys for automotive lock applications  

SciTech Connect (OSTI)

During the 1970s many automotive lock systems were converted from zinc die casting alloys to engineering plastics for reasons of weight and cost. Recent increases in requirements for precision and security have caused automotive and other lock designers to reconsider zinc alloy die-castings for these applications. To enable this, there is a need for mechanical property data comparable to that of the plastics materials used in these applications. In this work, rotary bending fatigue tests were performed on Alloys 3, 5, ZA-8 and AcuZinc 5 using an R.R. Moore fatigue machine. Testing was performed at 30 Hz and was stopped at 1x107 cycles. The fatigue limit results were compared to data reported in the literature for higher number of cycles and faster rotations.

Schrems, Karol K.; Dogan, Omer N.; Goodwin, F.E. (International Lead and Zinc Research Organization, Research Triangle, NC)

2004-06-01T23:59:59.000Z

70

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

71

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

72

Wind Technology Testing Center Acquires New Blade Fatigue Test...  

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

Technology Testing Center Acquires New Blade Fatigue Test System Wind Technology Testing Center Acquires New Blade Fatigue Test System August 1, 2013 - 4:33pm Addthis This is an...

73

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

74

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

75

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

76

Sparkr Blade Test Centre Fatigue tests of wind turbine blades  

E-Print Network [OSTI]

Sparkr Blade Test Centre Fatigue tests of wind turbine blades Flapwise fatigue tests of 3 blades wind load. By turning and oscillating the blade in the horzontal direction, an R-ratio of 1 running at the Sparkr Centre Blade Test Facilities. Fatigue blade tests are performed in order

77

PREDICTORS OF POST-STROKE FATIGUE  

E-Print Network [OSTI]

-stroke. 65 The severity of fatigue was examined using Fatigue Severity Scale (FSS) 34 and the Visual Analog Scale (VAS); 82 aerobic fitness was assessed at the peak level using a graded exercise protocol on a treadmill. In addition, timed 10-meter..., Pohl and colleagues evaluated the walking performance in people post-stroke. 85 Seventy-two people with chronic stroke were asked to complete the 6-minute walk test (6MWT); pulse and blood pressure were taken before and after the walk. Motor...

Tseng, Benjamin Yichen

2009-01-29T23:59:59.000Z

78

Langevin Equation on Fractal Curves  

E-Print Network [OSTI]

We analyse a random motion of a particle on a fractal curve, using Langevin approach. This involves defining a new velocity in terms of mass of the fractal curve, as defined in recent work. The geometry of the fractal curve, hence plays an important role in this analysis. A Langevin equation with a particular noise model is thus proposed and solved using techniques of the newly developed $F^\\alpha$-Calculus .

Seema Satin; A. D. Gangal

2014-04-28T23:59:59.000Z

79

Fatigue of Wind Blade Laminates:Fatigue of Wind Blade Laminates: Effects of Resin and Fabric Structure  

E-Print Network [OSTI]

Fatigue of Wind Blade Laminates:Fatigue of Wind Blade Laminates: Effects of Resin and Fabric University MCARE 2012 #12;Outline · Overview of MSU Fatigue Program on Wind Blade MaterialsWind Blade Wind Blade Component Materials Acknowledgements: Sandia National Laboratories/DOE (Joshua Paquette

80

CSC6870 Computer Graphics II Bezier Curves  

E-Print Network [OSTI]

CSC6870 Computer Graphics II Bezier Curves CSC6870 Computer Graphics II Bezier Curve CSC6870 Computer Graphics II Cubic Bezier Curves · Curve: · Control points · Basis functions: = = 3 0 3 )()( i ii uBpuc ip CSC6870 Computer Graphics II Bezier Curves (degree n) · Curve: · Control points · Basis functions

Hua, Jing

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

Actuation Fatigue of Shape Memory Alloys  

E-Print Network [OSTI]

A testing method was developed to cycle quickly and repeatably Ni60Ti40 (wt. %) SMA specimens through temperature-induced transformation while under constant stress until failure. Previous works have shown fatigue cracks to initiate in or around Ni3...

Calhoun, Christopher

2012-07-16T23:59:59.000Z

82

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

83

Random Curves by Conformal Welding  

E-Print Network [OSTI]

We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle given in terms of the exponential of Gaussian Free Field. We conjecture that our curves are locally related to SLE$(\\kappa)$ for $\\kappa<4$.

Astala, K; Kupiainen, A; Saksman, E

2009-01-01T23:59:59.000Z

84

Random Curves by Conformal Welding  

E-Print Network [OSTI]

We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle given in terms of the exponential of Gaussian Free Field. We conjecture that our curves are locally related to SLE$(\\kappa)$ for $\\kappa<4$.

K. Astala; P. Jones; A. Kupiainen; E. Saksman

2009-12-17T23:59:59.000Z

85

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

86

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

87

Assessment of Global Buckling and Fatigue Life for Steel Catenary RIser by Hull-Riser-Mooring Coupled Dynamic Analysis Program  

E-Print Network [OSTI]

the related techniques, software, rules and regulations. They outlined the analysis flow in which the procedure is initiated by design basis and leads to fatigue analysis of SCR including VIV, VIM and motion fatigue, emphasizing 6 the shell element... compression, downward hang-off heave velocity is the target of measurement. Assuming the length is unit length, the equations for the parameter and the variables are as follows: 29 2 min 2 0net d drag Ter alF m g C D V?? ? ? ? ? ? ? 2 /Terminal d...

Eom, Taesung

2013-08-01T23:59:59.000Z

88

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

89

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

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

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

90

Fatigue and Creep-Fatigue Deformation of an Ultra-Fine Precipitate Strengthened Advanced Austenitic Alloy  

SciTech Connect (OSTI)

An advanced austenitic alloy, HT-UPS (high-temperature ultrafine-precipitation-strengthened), has been identified as an ideal candidate material for the structural components of fast reactors and energy-conversion systems. HT-UPS alloys demonstrate improved creep resistance relative to 316 stainless steel (SS) through additions of Ti and Nb, which precipitate to form a widespread dispersion of stable nanoscale metallic carbide (MC) particles in the austenitic matrix. The low-cycle fatigue and creep-fatigue behavior of an HT-UPS alloy have been investigated at 650 C and a 1.0% total strain, with an R-ratio of -1 and hold times at peak tensile strain as long as 150 min. The cyclic deformation response of HT-UPS is directly compared to that of standard 316 SS. The measured values for total cycles to failure are similar, despite differences in peak stress profiles and in qualitative observations of the deformed microstructures. Crack propagation is primarily transgranular in fatigue and creep-fatigue of both alloys at the investigated conditions. Internal grain boundary damage in the form of fine cracks resulting from the tensile hold is present for hold times of 60 min and longer, and substantially more internal cracks are quantifiable in 316 SS than in HT-UPS. The dislocation substructures observed in the deformed material differ significantly; an equiaxed cellular structure is observed in 316 SS, whereas in HT-UPS the microstructure takes the form of widespread and relatively homogenous tangles of dislocations pinned by the nanoscale MC precipitates. The significant effect of the fine distribution of precipitates on observed fatigue and creep-fatigue response is described in three distinct behavioral regions as it evolves with continued cycling.

M.C. Carroll; L.J. Carroll

2012-10-01T23:59:59.000Z

91

The soil reference shrinkage curve  

E-Print Network [OSTI]

A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid density; (4) soil clay content; (5) oven-dried structural porosity; (6) the ratio of aggregate solid mass to solid mass of intraaggregate matrix; (7) the lacunar factor that characterizes the rate of the lacunar pore volume change with water content; and (8) oven-dried lacunar pore volume. The model was validated using available data. The model predicted value of the slope of the reference shrinkage curve in the basic shrinkage area is equal to unity minus the lacunar factor value, and is between unity and zero in the agreement with observations.

V. Y. Chertkov

2014-03-11T23:59:59.000Z

92

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...

93

A comparison of various methods used for crack resistance curve determination  

E-Print Network [OSTI]

bar, and Charpy V-notched) and were fatigue precracked and then tested under displacement control at room temperature. Jlc was determined using three approaches to reduce the experimental data: (1) ASTM E813-81; (2) a proposed modification to E813...-81 by Heerens, Schwalbe, and Cornec; and (3) ASTM E813-87, currently in press. The ASTM E813-87 analysis gave an average value of Jlc that was approximately 13/ higher than the E813-81 analysis. Crack resistance curves were generated using the current...

Cayard, Michael Scott

1987-01-01T23:59:59.000Z

94

Corrosion fatigue in nitrocarburized quenched and tempered steels  

SciTech Connect (OSTI)

In order to investigate the fatigue strength and fracture mechanism of salt bath nitrocarburized steels, specimens of the steels SAE 4135 and SAE 4140, in a quenched and tempered state, and additionally in a salt bath nitrocarburized and oxidizing cooled state as well as in a polished (after the oxidizing cooling) and renewed oxidized state, were subjected to comparative rotating bending fatigue tests in inert oil and 5 pct NaCl solution. In addition, some of the quenched and tempered specimens of SAE 4135 material were provided with an approximately 50-{mu}m-thick electroless Ni-P layer, in order to compare corrosion fatigue behavior between the Ni-P layer and the nitride layers. Long-life corrosion fatigue tests of SAE 4135 material were carried out under small stresses in the long-life range up to 10{sup 8} cycles with a test frequency of 100 Hz. Fatigue tests of SAE 4140 material were carried out in the range of finite life (low-cycle range) with a test frequency of 13 Hz. The results show that the 5 pct NaCl environment drastically reduced fatigue life, but nitrocarburizing plus oxidation treatment was found to improve the corrosion fatigue life over that of untreated and Ni-P coated specimens. The role of inclusions in initiating fatigue cracks was investigated. It was found that under corrosion fatigue conditions, the fatigue cracks started at cavities along the interfaces of MnS inclusions and matrix in the case of quenched and tempered specimens. The nitrocarburized specimens, however, showed a superposition of pitting corrosion and corrosion fatigue in which pores and nonmetallic inclusions in the compound layer play a predominant role concerning the formation of pits in the substrate.

Karim Khani, M.; Dengel, D. [Technical Univ. of Berlin (Germany). Dept. of Materials Technology

1996-05-01T23:59:59.000Z

95

Dynamics and Fatigue Damage of Wind Turbine Rotors  

E-Print Network [OSTI]

6 3 RiS0-Rr512 Dynamics and Fatigue Damage of Wind Turbine Rotors during Steady Operation Peter OF WIND TURBINE ROTORS DURING STEADY OPERATION Peter Hauge Madsen, Sten Frandsen, William E. Holley-carrying capacity of a wind turbine rotor with respect to short-term strength and material fatigue are presented

96

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

97

SANDIA CONTRACTORS REPORT FATIGUE OF COMPOSITE MATERIALS AND  

E-Print Network [OSTI]

SANDIA CONTRACTORS REPORT FATIGUE OF COMPOSITE MATERIALS AND SUBSTRUCTURES FOR WIND TURBINE BLADES Abstract ThisreportpresentsthemajorfindingsoftheMontanaStateUniversityCompositeMaterialsFatigue Program from 1997 to 2001, and is intended to be used in conjunction with the DOE/MSU Composite Materials

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

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

100

A PROBABILISTIC TWO-SCALE MODEL FOR HIGH CYCLE FATIGUE LIFE PREDICTIONS  

E-Print Network [OSTI]

volumes of a dual-phase steel. Keywords Fatigue limits; Weibull model; Microplasticity; Thermomechanics. 1

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

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

102

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

103

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

104

Harmonic algebraic curves and noncrossing partitions  

E-Print Network [OSTI]

Motivated by Gausss first proof of the fundamental Theorem of Algebra, we study the topology of harmonic algebraic curves. By the maximum principle, a harmonic curve has no bounded components; its topology is determined ...

Martin, Jeremy L.; Savitt, David; Singer, Ted

2007-02-01T23:59:59.000Z

105

Life prediction for bridged fatigue cracks  

SciTech Connect (OSTI)

One of the more promising classes of composites touted for high temperature applications, and certainly the most available, is that of relatively brittle matrices, either ceramic or intermetallic, reinforced by strong, aligned, continuous fibers. Under cyclic loading in the fiber direction, these materials develop matrix cracks that often run perpendicular to the fibers, while the fibers remain intact in the crack wake, supplying bridging tractions across the fracture surfaces. The bridging tractions shield the crack tip from the applied load, dramatically reducing the crack velocity from that expected in an unreinforced material subjected to the same value, {Delta}K{sub a}, of the cyclic applied stress intensity factor. An important issue in reliability is the prediction of the growth rates of the bridged cracks. The growth rates of matrix fatigue cracks bridged by sliding fibers are now commonly predicted by models based on the micromechanics of frictional interfaces. However, there exist many reasons, both theoretical and experimental, for suspecting that the most popular micromechanical models are probably wrong in detail in the context of fatigue cracks. Furthermore, a review of crack growth data reveals that the validity of the micromechanics-based predictive model has never been tested and may never be tested. In this paper, two alternative approaches are suggested to the engineering problem of predicting the growth rates of bridged cracks without explicit recourse to micromechanics. Instead, it is shown that the material properties required to analyze bridging effects can be deduced directly from crack growth data. Some experiments are proposed to test the validity of the proposals.

Cox, B.N.

1994-08-01T23:59:59.000Z

106

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

107

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

108

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

109

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

110

Grain size effects on the fatigue response of nanocrystalline materials  

E-Print Network [OSTI]

The resistance of metals and alloys to fatigue crack initiation and propagation is known to be influenced significantly by grain size. Based on a wealth of experimental results obtained from microcrystalline metals, where ...

Hanlon, Timothy, 1977-

2004-01-01T23:59:59.000Z

111

Predicting the fatigue life of asphalt concrete overlay systems  

E-Print Network [OSTI]

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... 1979 Major Subject: Civil Engineering PREDICTING THE FATIGUE LIFE OF ASPHALT CONCRETE OVERLAY SYSTEMS A Thesis by FREDERICK PHILIP GERMANN Approved as to style and content by: (Chair n of Commit e) (Head of Department) (Member) (Member) May...

Germann, Frederick P

1979-01-01T23:59:59.000Z

112

JAEA Fatigue Analysis of EBR-II Duplex Tubing  

SciTech Connect (OSTI)

This work addresses questions brought up concerning the mechanisms associated with fatigue crack growth retardation and/or arrest within the nickel bond layer in duplex 2 Cr-1Mo steel superheater tubes. Previous work performed at the Idaho National Laboratory (INL) indicated that the nickel bond layer did not function as a crack arrestor during fatigue crack propagation with the exception of one, isolated case involving an exceptionally low fatigue load and a high temperature (400 0C) environment. Since it is atypical for a fatigue crack to propagate from a relatively soft material (the nickel bond layer) to a harder material (the 2 Cr-1Mo steel) there has been speculation that the nickel bond layer was hardened in service. Additionally, there are questions surrounding the nature of the fatigue crack propagation within the nickel bond layer; specifically with regard to the presence of voids seen on micrographs of the bond layer and oxidation within the steel along the edge of the nickel bond layer. There is uncertainty as to the effect of these voids and/or oxide barriers with respect to potential fatigue crack arrest.

J. H. Jackson; D. L. Porter; W. R. Lloyd

2009-07-01T23:59:59.000Z

113

Dislocation substructure in fatigued duplex stainless steel  

SciTech Connect (OSTI)

Cyclic plastic straining of crystalline materials results in the formation of specific dislocation structures. Considerable progress in mapping and understanding internal dislocation structures has been achieved by studying single crystal behavior: however, most structural materials have a polycrystalline structure and investigations of polycrystals in comparison to single crystal behavior of simple metals prove to be very useful in understanding more complex materials. There are some classes of materials, however, with complicated structure which do not have a direct equivalent in single crystalline form. Moreover, the specific dimensions and shapes of individual crystallites play an important role both in the cyclic stress-strain response of these materials and in the formation of their interior structure in cyclic straining. Austenitic-ferritic duplex stainless steel, which is a kind of a natural composite, is a material of this type. The widespread interest in the application of duplex steels is caused by approximately doubled mechanical properties and equal corrosion properties, when compared with classical austenitic stainless steels. Fatigue resistance of these steels as well as the surface damage evolution in cyclic straining have been studied; however, much less is known about the internal substructure development in cyclic straining. In this study the dislocation arrangement in ferritic and austenitic grains of the austenitic-ferritic duplex steel alloyed with nitrogen and cyclically strained with two strain amplitudes, is reported and compared to the dislocation arrangement found in single and polycrystals of austenitic and ferritic materials of a similar composition and with the surface relief produced in cyclic plastic straining.

Polak, J. (Ecole Centrale de Lille, Villeneuve d'Ascq (France). Lab. de Mecanique de Lille Inst. of Physical Metallurgy, Brno (Czechoslovakia). Academy of Sciences); Degallaix, S. (Ecole Centrale de Lille, Villeneuve d'Ascq (France). Lab. de Mecanique de Lille); Kruml, T. (Inst. of Physical Metallurgy, Brno (Czechoslovakia). Academy of Sciences)

1993-12-15T23:59:59.000Z

114

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

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

Learning Curve - DOE Directives, Delegations, and Requirements  

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

This chapter discusses the development and application of the learning curve. g4301-1chp21.pdf -- PDF Document, 28 KB Writer: John Makepeace Subjects: Administration Management...

118

Fatigue performance and cyclic softening of F82H, a ferritic martensic steel  

SciTech Connect (OSTI)

The room temperature fatigue performance of F82H has been examined. The fatigue life was determined in a series of strain-controlled tests where the stress level was monitored as a function of the number of accrued cycles. Fatigue lives in the range of 10{sup 3} to 10{sup 6} cycles to failure were examined. The fatigue performance was found to be controlled primarily by the elastic strain range over most of the range of fatigue lives examined. Only at low fatigue lives did the plastic strain range contribute to the response. However, when the significant plastic strain did contribute, the material showed a tendency to cyclically soften. That is the load carrying capability of the material degrades with accumulated fatigue cycles. The overall fatigue performance of the F82H alloy was found to be similiar to other advanced martensitic steels, but lower than more common low alloy steels which possess lower yield strengths.

Stubbins, J.F. [Univ. of Illinois, Urbana, IL (United States); Gelles, D.S. [Pacific Northwest National Laboratory, Richland, WA (United States)

1996-04-01T23:59:59.000Z

119

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

120

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...

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

Enhanced ultrasonic detection of fatigue cracks by laser-induced crack closure  

E-Print Network [OSTI]

, corrosion, etc. . Sec- ond, it is important to distinguish small fatigue cracks as early as possible after threshold in aluminum, aluminum lithium, and titanium alloys.1 For example, extensive multiple-site fatigue

Nagy, Peter B.

122

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

123

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

124

A Model to Predict Work-Related Fatigue Based on Hours of Work  

E-Print Network [OSTI]

A Model to Predict Work-Related Fatigue Based on Hours of Work Gregory D. Roach, Adam Fletcher, and Drew Dawson ROACH GD, FLETCHER A, DAWSON D. A model to predict work- related fatigue based on hours

125

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

126

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

127

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

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

Design, prototyping and preliminary testing of an elastic-powered climbing exoskeleton  

E-Print Network [OSTI]

Human powered elastic mechanisms can be used to reduce work requirements of muscles, by storing and releasing energy to more evenly distribute work load. An exoskeleton was designed to delay human fatigue during rock ...

Briner, Hazel (Hazel Linn)

2011-01-01T23:59:59.000Z

131

Development of load and resistance factor design for FRP strengthening of reinforced concrete structures  

E-Print Network [OSTI]

Design for FRP Strengthening of Reinforced Concrete. In 7 thFRP) Reinforcement for Concrete Structure; Shield, C.K. ,G.C. Fatigue Performance of Concrete Beams Strengthened with

Atadero, Rebecca Anne

2006-01-01T23:59:59.000Z

132

A continuum damage modelling of quasi-static fatigue strength of plain concrete  

E-Print Network [OSTI]

A continuum damage modelling of quasi-static fatigue strength of plain concrete S. H. Maia,b , F of concrete. The approach is based on the framework of continuum damage mechanics where the fatigue model fatigue tests have been performed on a concrete the formulation of which is close to the one used

Paris-Sud XI, Université de

133

Effects of Glass Fabric and Laminate Construction on the Fatigue of Resin Infused Blade Materials  

E-Print Network [OSTI]

Effects of Glass Fabric and Laminate Construction on the Fatigue of Resin Infused Blade Materials. Introduction Wind turbine blades experience very high numbers of fatigue cycles varying between tension and wind conditions. The fatigue of composite laminates appropriate for wind turbine blades has been

134

Mental fatigue evaluation by steroid level measurement in Parotid fluid  

E-Print Network [OSTI]

Play 1968 Major Subject. : Inc'ustrial Engineering MENTAL FATIGUE EVALUATION BY STEROID LEVEL MEASURLMENT. IN PAROTID FLUID A Thesis by HARPAL SINGH ApproveH as to tyle and. content by: P'hpirman of Committee) (Memb sr ) 1 1 PREFACE Alta...&ough indu trial engineering has had a phenomenal growth rate, a certain basic avenue has not been explored. The avenue 1 am refer- ring to is that of human fatigue and related phenomena. The reasons for this neglect are basically two: (1) Tnvestigation...

Singh, Harpal

1968-01-01T23:59:59.000Z

135

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

136

Mechanisms for fatigue and wear of polysilicon structural thinfilms  

SciTech Connect (OSTI)

Fatigue and wear in micron-scale polysilicon structural films can severely impact the reliability of microelectromechanical systems (MEMS). Despite studies on fatigue and wear behavior of these films, there is still an on-going debate regarding the precise physical mechanisms for these two important failure modes. Although macro-scale silicon does not fatigue, this phenomenon is observed in micron-scale silicon. It is shown that for polysilicon devices fabricated in the MUMPs foundry and SUMMiT process stress-lifetime data exhibits similar trends in ambient air, shorter lifetimes in higher relative humidity environments and no fatigue failure at all in high vacuum. Transmission electron microscopy of the surface oxides of the samples show an approximate four-fold thickening of the oxide at stress concentrations after fatigue failure, but no thickening after fracture in air or after fatigue cycling in vacuo. It is found that such oxide thickening and fatigue failure (in air) occurs in devices with initial oxide thicknesses of {approx}4-20 nm. Such results are interpreted and explained by a reaction layer fatigue mechanism; specifically, moisture-assisted subcritical cracking within a cyclic stress-assisted thickened oxide layer occurs until the crack reaches a critical size to cause catastrophic failure. Polysilicon specimens from the SUMMiT process are used to study wear mechanisms in micron-scale silicon in ambient air. Worn parts are examined by analytical scanning and transmission electron microscopy, while temperature changes are monitored using infrared microscopy. These results are compared with the development of values of static coefficients of friction (COF) with number of wear cycles. Observations show amorphous debris particles ({approx}50-100 nm) created by fracture through the silicon grains ({approx}500 nm), which subsequently oxidize, agglomerate into clusters and create plowing tracks. A nano-crystalline layer ({approx}20-200 nm) forms at worn regions. No dislocations or extreme temperature increases are found, ruling out plasticity and temperature-assisted mechanisms. The COF reaches a steady-state value of {approx}0.20{+-}0.05 after a short time at an initial value of {approx}0.11{+-}0.01. Plowing tracks are found before the steady-state value of the COF is reached, suggesting only a short adhesive wear regime. This suggests a predominantly abrasive wear mechanism, controlled by fracture, which commences by the first particles created by adhesive wear.

Alsem, Daniel Henricus

2006-12-01T23:59:59.000Z

137

Creep and Creep-Fatigue Crack Growth at Structural Discontinuities and Welds  

SciTech Connect (OSTI)

The subsection ASME NH high temperature design procedure does not admit crack-like defects into the structural components. The US NRC identified the lack of treatment of crack growth within NH as a limitation of the code and thus this effort was undertaken. This effort is broken into two parts. Part 1, summarized here, involved examining all high temperature creep-fatigue crack growth codes being used today and from these, the task objective was to choose a methodology that is appropriate for possible implementation within NH. The second part of this task, which has just started, is to develop design rules for possible implementation within NH. This second part is a challenge since all codes require step-by-step analysis procedures to be undertaken in order to assess the crack growth and life of the component. Simple rules for design do not exist in any code at present. The codes examined in this effort included R5, RCC-MR (A16), BS 7910, API 579, and ATK (and some lesser known codes). There are several reasons that the capability for assessing cracks in high temperature nuclear components is desirable. These include: (1) Some components that are part of GEN IV reactors may have geometries that have sharp corners - which are essentially cracks. Design of these components within the traditional ASME NH procedure is quite challenging. It is natural to ensure adequate life design by modeling these features as cracks within a creep-fatigue crack growth procedure. (2) Workmanship flaws in welds sometimes occur and are accepted in some ASME code sections. It can be convenient to consider these as flaws when making a design life assessment. (3) Non-destructive Evaluation (NDE) and inspection methods after fabrication are limited in the size of the crack or flaw that can be detected. It is often convenient to perform a life assessment using a flaw of a size that represents the maximum size that can elude detection. (4) Flaws that are observed using in-service detection methods often need to be addressed as plants age. Shutdown inspection intervals can only be designed using creep and creep-fatigue crack growth techniques. (5) The use of crack growth procedures can aid in examining the seriousness of creep damage in structural components. How cracks grow can be used to assess margins on components and lead to further safe operation. After examining the pros and cons of all these methods, the R5 code was chosen as the most up-to-date and validated high temperature creep and creep fatigue code currently used in the world at present. R5 is considered the leader because the code: (1) has well established and validated rules, (2) has a team of experts continually improving and updating it, (3) has software that can be used by designers, (4) extensive validation in many parts with available data from BE resources as well as input from Imperial college's database, and (5) was specifically developed for use in nuclear plants. R5 was specifically developed for use in gas cooled nuclear reactors which operate in the UK and much of the experience is based on materials and temperatures which are experienced in these reactors. If the next generation advanced reactors to be built in the US used these same materials within the same temperature ranges as these reactors, then R5 may be appropriate for consideration of direct implementation within ASME code NH or Section XI. However, until more verification and validation of these creep/fatigue crack growth rules for the specific materials and temperatures to be used in the GEN IV reactors is complete, ASME should consider delaying this implementation. With this in mind, it is this authors opinion that R5 methods are the best available for code use today. The focus of this work was to examine the literature for creep and creep-fatigue crack growth procedures that are well established in codes in other countries and choose a procedure to consider implementation into ASME NH. It is very important to recognize that all creep and creep fatigue crack growth procedures that are part of high temperature

Dr. F. W. Brust; Dr. G. M. Wilkowski; Dr. P. Krishnaswamy; Mr. Keith Wichman

2010-01-27T23:59:59.000Z

138

A combined mode fatigue model for glass reinforced nylon as applied to molded engine cooling fans  

SciTech Connect (OSTI)

The use of glass reinforced nylon in fatigue inducing environments calls for a new method of stress analysis. With an engine cooling fan, both mean and vibratory stresses need to be examined. Speed cycling can cause tensile fatigue, while vibration can cause flexural fatigue. Since tensile and flexural stresses exist in the fan simultaneously, a combined mode fatigue model is needed. The proposed model is based on high cycle flexural and tensile fatigue strengths, and tensile strength. It relates measurable strain to stress using temperature dependent flexural and tensile moduli, and treats underhood temperature and desired product life as variables.

Smith, J.D.; Bennet, M.L.

1985-01-01T23:59:59.000Z

139

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

140

Finding the Energy Efficient Curve: Gate Sizing for Minimum Power under Delay Constraints  

E-Print Network [OSTI]

Finding the Energy Efficient Curve: Gate Sizing for Minimum Power under Delay Constraints Yoni in a fast circuit by the same factor does not yield an energy-efficient design, and we characterize efficient. A design implementation is considered to be energy efficient when it has the highest performance

Kolodny, Avinoam

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

Modelling of fatigue damage in aluminum cylinder heads. R. Salapeteb  

E-Print Network [OSTI]

. 1. INTRODUCTION Increase in the specific power of Diesel engines leads to severe operating fatigue damage that may cause Diesel engine to fail after a few thousand cycles on the test bench and under severe operating conditions. The alternative heating and cooling of the operative Diesel engine

Paris-Sud XI, Université de

142

amplitude fatigue test: Topics by E-print Network  

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

amplitude fatigue test First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Standard practice for...

143

Fatigue tests of under-strenghth timber railroad bridge stringers  

E-Print Network [OSTI]

, experimentally, the fatigue behavior of under-strength timber railroad bridge stringers. The sample group that was tested included nineteen southern pine solid-sawn stringers that were 178 mm (7 in.) wide by 356 mm (14 in.) deep by 4.8 m (16 ft) long...

Borchers, Christopher Ryan

2002-01-01T23:59:59.000Z

144

Selection of Wind Turbine Blade Materials for Fatigue Resistance  

E-Print Network [OSTI]

Selection of Wind Turbine Blade Materials for Fatigue Resistance John Mandell Montana State center to center26 inch center to center #12;Blade Infusion L Lab InfusionLab Infusion #12;Schematic blade laminates Complex structured coupons with ply drops Complex structured coupons with ply drops

145

Ris-R-1261(EN) Fatigue Degradation and Failure of  

E-Print Network [OSTI]

. Such applications are for instance rotor blades in wind turbines, helicopter rotor blades, flywheels for energyRis-R-1261(EN) Fatigue Degradation and Failure of Rotating Composite Structures Materials Characterisation and Underlying Mechanisms E. Kristofer Gamstedt and Svend Ib Andersen Materials Research

146

Classification and forecasting of load curves Nolwen Huet  

E-Print Network [OSTI]

Classification and forecasting of load curves Nolwen Huet Abstract The load curve, which gives of electricity customer uses. This load curve is only available for customers with automated meter reading. For the others, EDF must estimate this curve. Usually a clustering of the load curves is performed, followed

Cuesta, Juan Antonio

147

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

148

Diffusion-Limited Aggregation on Curved Surfaces  

E-Print Network [OSTI]

We develop a general theory of transport-limited aggregation phenomena occurring on curved surfaces, based on stochastic iterated conformal maps and conformal projections to the complex plane. To illustrate the theory, we ...

Choi, J.

149

Learning Curve Management in Educational Programming Environments  

E-Print Network [OSTI]

Learning Curve Management in Educational Programming Environments Benjamin H. Brinckerhoff Computer programmers are best served by integrated development environments that adapt to their growing sophistication programming environments. We provide pedagogical justification for each goal, describe possible supporting

Goldman, Kenneth J.

150

Chiral gap effect in curved space  

E-Print Network [OSTI]

We discuss a new type of QCD phenomenon induced in curved space. In the QCD vacuum a mass gap of Dirac fermions is attributed to the spontaneous breaking of chiral symmetry. If the curvature is positive large, the chiral condensate melts but a chiral invariant mass gap can still remain, which we name the chiral gap effect in curved space. This leads to decoupling of quark deconfinement which implies a view of black holes surrounded by a first-order QCD phase transition.

Antonino Flachi; Kenji Fukushima

2014-06-25T23:59:59.000Z

151

Environmental bias and elastic curves on surfaces  

E-Print Network [OSTI]

The behavior of an elastic curve bound to a surface will reflect the geometry of its environment. This may occur in an obvious way: the curve may deform freely along directions tangent to the surface, but not along the surface normal. However, even if the energy itself is symmetric in the curve's geodesic and normal curvatures, which control these modes, very distinct roles are played by the two. If the elastic curve binds preferentially on one side, or is itself assembled on the surface, not only would one expect the bending moduli associated with the two modes to differ, binding along specific directions, reflected in spontaneous values of these curvatures, may be favored. The shape equations describing the equilibrium states of a surface curve described by an elastic energy accommodating environmental factors will be identified by adapting the method of Lagrange multipliers to the Darboux frame associated with the curve. The forces transmitted to the surface along the surface normal will be determined. Features associated with a number of different energies, both of physical relevance and of mathematical interest, are described. The conservation laws associated with trajectories on surface geometries exhibiting continuous symmetries are also examined.

Jemal Guven; Dulce Mara Valencia; Pablo Vzquez-Montejo

2014-08-15T23:59:59.000Z

152

Thermomechanical fatigue behavior of three CFCC`s. Final contractor report  

SciTech Connect (OSTI)

The thermomechanical fatigue (TMF) behavior of three continuous-fiber ceramic composites (CFCC`s) was examined. The three matrices consisted of two different glass-ceramics and silicon carbide, respectively. The matrices of some of the specimens with the silicon carbide matrix were enhanced to improve oxidation resistance. All three were reinforced with Nicalon fibers with various fiber architectures. The thermoelastic properties of the matrix relative to the fibers, the elastic moduli and coefficients of thermal expansion (CTE), were different in each composite, providing a comparison of the effects of these critical properties. The specimens were tested under in-phase (IP) and out-of-phase (OP) cyclic loadings with respect to thermal cycling between 600 C and 1100 C. One of the glass-ceramic composites had greatly increased TMF lives compared to the other glass-ceramic matrix composites. This was probably caused by the reversal of the CTE mismatch between the fibers and the matrices and caused by the different oxidation resistances of the composites. For the same TMF lives a cross-ply reinforced composite had a maximum cyclic stress half as great, as that of unidirectionally reinforced composite. This indicated that the (0 deg) ply fibers had a strong influence of TMF life. Both the glass ceramic matrix composites had shallow-slope stress-life plots that indicated sensitivity to damage and therefore low damage tolerance. The composites with an unenhanced silicon carbide matrix experienced the shortest TMF lives of all the CFCC`s tested. However, the enhanced composite had the longest. Also, the enhanced composite demonstrated the best damage tolerance as evidenced by a stress-life curve that curves sharply upward to the left. In all the composites, out-of-phase cyclic loading was worse than in-phase cyclic loadings despite the CTE mismatch between fiber and matrix.

Worthem, D.W.

1995-03-01T23:59:59.000Z

153

Fatigue flaw growth assessment and inclusion of stratification to the LBB assessment  

SciTech Connect (OSTI)

The application of the LBB requires also fatigue flaw growth assessment. This analysis was performed for PWR nuclear power plants types VVER 440/230, VVER 440/213c, VVER 1000/320. Respecting that these NPP`s were designed according to Russian codes that differ from US codes it was needed to compare these approaches. Comparison with our experimental data was accomplished, too. Margins of applicability of the US methods and their modifications for the materials used for construction of Czech and Slovak NPP`s are shown. Computer code accomplishing the analysis according to described method is presented. Some measurement and calculations show that thermal stratifications in horizontal pipelines can lead to additive loads that are not negligible and can be dangerous. An attempt to include these loads induced by steady-state stratification was made.

Samohyl, P.

1997-04-01T23:59:59.000Z

154

Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length  

SciTech Connect (OSTI)

With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.

Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.

2013-07-01T23:59:59.000Z

155

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...

156

Updated U.S. Geothermal Supply Curve  

SciTech Connect (OSTI)

This paper documents the approach used to update the U.S. geothermal supply curve. The analysis undertaken in this study estimates the supply of electricity generation potential from geothermal resources in the United States and the levelized cost of electricity (LCOE), capital costs, and operating and maintenance costs associated with developing these geothermal resources. Supply curves were developed for four categories of geothermal resources: identified hydrothermal (6.4 GWe), undiscovered hydrothermal (30.0 GWe), near-hydrothermal field enhanced geothermal systems (EGS) (7.0 GWe) and deep EGS (15,900 GWe). Two cases were considered: a base case and a target case. Supply curves were generated for each of the four geothermal resource categories for both cases. For both cases, hydrothermal resources dominate the lower cost range of the combined geothermal supply curve. The supply curves indicate that the reservoir performance improvements assumed in the target case could significantly lower EGS costs and greatly increase EGS deployment over the base case.

Augustine, C.; Young, K. R.; Anderson, A.

2010-02-01T23:59:59.000Z

157

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

158

Elliptic Curves and Hyperdeterminants in Quantum Gravity  

E-Print Network [OSTI]

Hyperdeterminants are generalizations of determinants from matrices to multi-dimensional hypermatrices. They were discovered in the 19th century by Arthur Cayley but were largely ignored over a period of 100 years before once again being recognised as important in algebraic geometry, physics and number theory. It is shown that a cubic elliptic curve whose Mordell-Weil group contains a Z2 x Z2 x Z subgroup can be transformed into the degree four hyperdeterminant on a 2x2x2 hypermatrix comprising its variables and coefficients. Furthermore, a multilinear problem defined on a 2x2x2x2 hypermatrix of coefficients can be reduced to a quartic elliptic curve whose J-invariant is expressed in terms of the hypermatrix and related invariants including the degree 24 hyperdeterminant. These connections between elliptic curves and hyperdeterminants may have applications in other areas including physics.

Philip Gibbs

2010-10-20T23:59:59.000Z

159

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

160

Mixed Mode Static and Fatigue Crack Growth in Wind Blade Paste Adhesives  

E-Print Network [OSTI]

, static GIc and mixed mode fracture, and fatigue crack growth resistance. I. Introduction Wind turbine blades are large composite structures which are typically resin infusion molded in sections

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

Modeling Metal Fatigue As a Key Step in PV Module Life Time Prediction (Presentation)  

SciTech Connect (OSTI)

This presentation covers modeling metal fatigue as a key step in photovoltaic (PV) module lifetime predictions. Described are time-dependent and time-independent case studies.

Bosco, N.

2012-02-01T23:59:59.000Z

162

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......

163

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...

164

E-Print Network 3.0 - alloy fatigue strength Sample Search Results  

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

alloys R. FOUGERES INSA de Lyon, Laboratoire GEMPPM, U... - Introduction Fatigue damage of metals and alloys involves complex phenomena arising at different scales......

165

Author's personal copy Statistical pattern analysis of ultrasonic signals for fatigue damage detection  

E-Print Network [OSTI]

-engineered complex electromechanical systems (e.g., aircraft, electric power generation units, and petrochemical plants). Accumulation of fatigue damage may cause catastrophic failures, leading to potential loss

Ray, Asok

166

Conservation Screening Curves to Compare Efficiency Investments to Power Plants  

E-Print Network [OSTI]

methodology to compare supply and demand-side resources. The screening curve approach supplements with load 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

167

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

168

Research Summary Estimating Woodfuel Resource Cost Curves  

E-Print Network [OSTI]

Research Summary Estimating Woodfuel Resource Cost Curves As a renewable energy source, woodfuel and extraction methods. Background Just under half of the final energy consumed in the UK (49%) is in the form working slope for the chosen type of machinery) and soil conditions (risk of soil damage). Note

169

The Elliptic Curve Digital Signature Algorithm (ECDSA)  

E-Print Network [OSTI]

). It was accepted in 1999 as an ANSI standard, and was accepted in 2000 as IEEE and NIST standards. It was also-per-key-bit is substantially greater in an algorithm that uses elliptic curves. This paper describes the ANSI X9.62 ECDSA Standards Organization) standard (ISO 14888-3), accepted in 1999 as an ANSI (American National Standards

170

Closed timelike curves in general relativity  

E-Print Network [OSTI]

Many solutions of Einstein's field equations contain closed timelike curves (CTC). Some of these solutions refer to ordinary materials in situations which might occur in the laboratory, or in astrophysics. It is argued that, in default of a reasonable interpretation of CTC, general relativity does not give a satisfactory account of all phenomena within its terms of reference.

W. B. Bonnor

2002-11-13T23:59:59.000Z

171

WILD MODELS OF CURVES DINO LORENZINI  

E-Print Network [OSTI]

WILD MODELS OF CURVES DINO LORENZINI Abstract. Let K be a complete discrete valuation field of X/K obtained by desingularizing the wild quotient singularities of the quotient Y/H. The most of wild quotient singularities having pairwise distinct resolution graphs. The information on the regular

Lorenzini, Dino J.

172

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

173

Measured performances of curved inverted-vee, absorber compound parabolic concentrating solar-energy collectors  

SciTech Connect (OSTI)

The design and thermal performance of modified compound parabolic concentrating (CPC) solar-energy collectors are described. The designs incorporate a curved inverted-Vee absorber fin, which allows a reflector of simple geometry to be used. This CPC collector, has exhibited a superior performance to that of a conventional cusp-reflector CPC design, owing to the enhancement of the optical efficiency obtained by eliminating gap optical losses and an enhanced heat removal factor. The consequence upon the performance of a further design refinement, which inhibited the convective heat losses, is also reported.

Norton, B. (Univ. of Ulster at Jordanstown (Ireland)); Prapas, D.E. (Aristotle Univ. of Thessaloniki (Greece)); Eames, P.C.; Probert, S.D. (Cranfield Institute of Technology, Bedford (England))

1989-01-01T23:59:59.000Z

174

Modeling cyclic ratcheting based fatigue life of HSLA steels using crystal plasticity FEM simulations and experiments  

E-Print Network [OSTI]

Modeling cyclic ratcheting based fatigue life of HSLA steels using crystal plasticity FEM This paper develops a plastic ratcheting based fatigue failure model for HSLA steels from a combination. It predicts the nucleation of major cracks in the microstruc- ture in ratcheting. Subsequently, the total life

Ghosh, Somnath

175

Effect of diaphragmatic fatigue on control of the respiratory muscles during CO sub 2 rebreathing  

SciTech Connect (OSTI)

The authors measured respiratory muscle recruitment and ventilation ({dot V}{sub E}) during CO{sub 2} rebreathing before and after diaphragmatic fatigue in normal subjects. Muscle activity was assessed by measuring pleural, abdominal, and transdiaphragmatic pressures (Ppl, Pab, and Pdi, resp). The results showed that (1) there was a progressive increase in Pdi with increasing end-tidal PCO{sub 2} (P{sub ET}CO{sub 2}); the rate of increase was usually greater before than after fatigue, however, in some it was less because of longer operating length and/or passive stretching of the diaphragm due to strong rib cage muscle (RCM) activity induced by fatigue; (2) Pdi increased mainly due to greater fall in Ppl; {Delta}Pab increased little during CO{sub 2} rebreathing or even decreased with P{sub ET}CO{sub 2} over 50-55 mmHg; this pattern was exaggerated by fatigue; (3) at the end of each trial, the ratio {minus}{Delta}Ppl/{Delta}Pab increased by {approximately}140% before and {approximately}850% after fatigue; (4) CO{sub 2} induced expiratory abdominal muscle activity; and (5) as a group, {dot V}{sub E} and its pattern did not change appreciably with fatigue. The authors conclude that RCM are recruited proportionately more than the diaphragm by CO{sub 2} and that diaphragmatic fatigue shifts the central drive from the fatigued diaphragm to TCM to preserve ventilation.

Yan, S.; Lichros, I.; Macklem, P.T. (McGill Univ., Montreal, Quebec (Canada) Montreal Chest Hospital, Quebec (Canada))

1991-03-11T23:59:59.000Z

176

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

E-Print Network [OSTI]

- 1 - THERMAL FATIGUE AND FAILURE OF ELECTRONIC POWER DEVICE SUBSTRATES. S. Pietranico1&2 , S, avenue du Président Wilson, 94235 Cachan, France Abstract: Electronic power devices used shows that the fatigue life and the reliability of power electronic devices could be optimized using

177

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

178

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

179

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

180

Statistical Analysis of High-Cycle Fatigue Behavior of Friction Stir Welded AA5083-H321  

E-Print Network [OSTI]

Statistical Analysis of High-Cycle Fatigue Behavior of Friction Stir Welded AA5083-H321 M. Grujicic AA5083, fatigue behavior, friction stir welding, maximum likelihood estimation 1. Introduction Friction stir welding (FSW) is a relatively new solid-state metal-joining process that was invented

Grujicic, Mica

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

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

182

November 1998 NREL/SR-500-24379 Fatigue of Composite Material Beam  

E-Print Network [OSTI]

No. DE-AC36-83CH10093 #12;Fatigue of Composite Material Beam Elements Representative of Wind TurbineNovember 1998 NREL/SR-500-24379 Fatigue of Composite Material Beam Elements Representative of Wind Turbine Blade Substructure John F. Mandell, Daniel D. Samborsky, David W. Combs, M. Ethan Scott

183

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

E-Print Network [OSTI]

in three areas are described for wind blade materials in the SNL/MSU/DOE fatigue of composite materials from over 250 materials systems relevant to wind blades, is now formatted in Excel, allowing more of the tensile fatigue sensitivity of various blade materials including laminate in-plane and interlaminar

184

Comparing Estimates of Wind Turbine Fatigue Loads using Time-Domain and Spectral Methods  

E-Print Network [OSTI]

for edgewise blade loads. NOMENCLATURE f = frequency in Hertz m = material exponent for fatigue mn = nthComparing Estimates of Wind Turbine Fatigue Loads using Time-Domain and Spectral Methods by Patrick Ragan and Lance Manuel REPRINTED FROM WIND ENGINEERING VOLUME 31, NO. 2, 2007 MULTI-SCIENCE PUBLISHING

Manuel, Lance

185

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

186

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

187

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

188

Proceeding of Energy Week 1996, ASME APPLICATION OF THE U.S. HIGH CYCLE FATIGUE DATA BASE  

E-Print Network [OSTI]

TURBINE BLADE LIFETIME PREDICTIONS Herbert J. Sutherland Wind Energy Technology Sandia National the service lifetime of wind turbine blades using the high-cycle fatigue data base for typical U.S. blade blades. The LIFE2 fatigue analysis code for wind turbines is then used for the fatigue analysis

189

Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies  

SciTech Connect (OSTI)

The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce compressive residual stress at weld toe for weld fatigue resistance.

Yang, Z.; Dong, P.; Liu, S.; Babu, S.; Olson, G.; DebRoy, T.

2005-04-15T23:59:59.000Z

190

Improving Fatigue Performance of AHSS Welds | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Improving Fan System Performance a sourcebook forFatigue

191

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

192

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

193

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

194

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

195

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

196

Rotation Curve Measurement using Cross-Correlation  

E-Print Network [OSTI]

Longslit spectroscopy is entering an era of increased spatial and spectral resolution and increased sample size. Improved instruments reveal complex velocity structure that cannot be described with a one-dimensional rotation curve, yet samples are too numerous to examine each galaxy in detail. Therefore, one goal of rotation curve measurement techniques is to flag cases in which the kinematic structure of the galaxy is more complex than a single-valued curve. We examine cross-correlation as a technique that is easily automated and works for low signal-to-noise spectra. We show that the technique yields well-defined errors which increase when the simple spectral model (template) is a poor match to the data, flagging those cases for later inspection. We compare the technique to the more traditional, parametric technique of simultaneous emission line fitting. When the line profile at a single slit position is non-Gaussian, the techniques disagree. For our model spectra with two well-separated velocity components, assigned velocities from the two techniques differ by up to ~52% of the velocity separation of the model components. However, careful use of the error statistics for either technique allows one to flag these non-Gaussian spectra.

Elizabeth J. Barton; Sheila J. Kannappan; Michael J. Kurtz; Margaret J. Geller

2000-06-20T23:59:59.000Z

197

Incorporating Experience Curves in Appliance Standards Analysis  

SciTech Connect (OSTI)

The technical analyses in support of U.S. energy conservation standards for residential appliances and commercial equipment have typically assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. There is, however, considerable evidence that this assumption does not reflect real market prices. Costs and prices generally fall in relation to cumulative production, a phenomenon known as experience and modeled by a fairly robust empirical experience curve. Using price data from the Bureau of Labor Statistics, and shipment data obtained as part of the standards analysis process, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These allow us to develop more representative appliance price projections than the assumption-based approach of constant prices. These experience curves were incorporated into recent energy conservation standards for these products. The impact on the national modeling can be significant, often increasing the net present value of potential standard levels in the analysis. In some cases a previously cost-negative potential standard level demonstrates a benefit when incorporating experience. These results imply that past energy conservation standards analyses may have undervalued the economic benefits of potential standard levels.

Garbesi, Karina; Chan, Peter; Greenblatt, Jeffery; Kantner, Colleen; Lekov, Alex; Meyers, Stephen; Rosenquist, Gregory; Buskirk, Robert Van; Yang, Hung-Chia; Desroches, Louis-Benoit

2011-10-31T23:59:59.000Z

198

Variations in gear fatigue life for different wind turbine braking strategies  

SciTech Connect (OSTI)

A large number of gearbox failures have occurred in the wind industry in a relatively short period, many because service loads were underestimated. High-torque transients that occur during starting and stopping are difficult to predict and may be overlooked in specifying gearbox design. Although these events comprise a small portion of total load cycles, they can be the most damaging. The severity of these loads varies dramatically with the specific configuration of the wind turbine. The large number of failures in Danish-designed Micon 65 wind turbines prompted this investigation. The high-speed and low-speed shaft torques were measured on a two-stage helical gearbox of a single Micon 65 turbine. Transient events and normal running loads were combined statistically to obtain a typical annual load spectrum. The pitting and bending fatigue lives of the gear teeth were calculated by using Miner's rule for four different high-speed shaft brake configurations. Each breaking scenario was run for both a high- and a low-turbulence normal operating load spectrum. The analysis showed increases in gear life by up to a factor of 25 when the standard high-speed shaft brake is replaced with a dynamic brake or modified with a damper. 9 refs., 9 figs., 3 tabs.

McNiff, B.P. (Second Wind, Inc., Somerville, MA (USA)); Musial, W.D. (Solar Energy Research Inst., Golden, CO (USA)); Errichello, R. (GEARTECH, Albany, CA (USA))

1991-06-01T23:59:59.000Z

199

Structural Design Criteria Irving J. Zatz, PPPL  

E-Print Network [OSTI]

unresolvable behavior, perform detailed analysis to determine limit load and apply safety factor of 2 #12 difference in principal stresses On an S-n curve, allowable stress amplitude limited to the lesser of: 1 and combined via a linear damage relationship and based on the design S-n curve For FIRE, the 3000 full power

200

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

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

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

202

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

203

Modeling software artifact count attribute with s-curves  

E-Print Network [OSTI]

????????.???????. 44 16 Linear graph of various intercept parameter values ????????... 45 17 S-curves with various generator parameter values ?????????. 46 18 Linear fit with various generator parameter values ????????? 47 19 S-curve with various expected maximum... Artifact Graph (NPAG) Format ????.. 34 D. S-curve and Straight Line Description .......................................... 41 1. The Readiness Parameter ?????????????. 44 2. The Generation Parameter ????????????? 46 3. The S-curve Constant...

Ma, Norman K.

2009-05-15T23:59:59.000Z

204

Modeling software artifact count attribute with s-curves  

E-Print Network [OSTI]

.. 44 16 Linear graph of various intercept parameter values ... 45 17 S-curves with various generator parameter values . 46 18 Linear fit with various generator parameter values 47 19 S-curve with various expected maximum... Artifact Graph (NPAG) Format .. 34 D. S-curve and Straight Line Description .......................................... 41 1. The Readiness Parameter . 44 2. The Generation Parameter 46 3. The S-curve Constant...

Ma, Norman K

2008-10-10T23:59:59.000Z

205

Algorithms for Mumford Curves Ralph Morrison and Qingchun Ren  

E-Print Network [OSTI]

discuss specific methods and future work for hyperelliptic Mumford curves. 1. Introduction Curves over non geometry, which looks at the images in Rn of curves under coordinate-wise valuation, these are balanced complete with respect to a nontrivial non-archimedean valuation. Unless otherwise stated, | | will denote

Boyer, Edmond

206

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

207

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

208

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

209

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

210

Tracking Endocardium Using Optical Flow along Iso-Value Curve  

E-Print Network [OSTI]

1 Tracking Endocardium Using Optical Flow along Iso-Value Curve Qi Duan1, Elsa D. Angelini2 indicators. A framework of optical flow along iso-value curves is proposed and applied to several cardiac;9 OF along Iso-value Curves In myocardial motion analysis, motion fields are projected along specific

211

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

212

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

213

Wave regularity in curve integrable spacetimes  

E-Print Network [OSTI]

The idea of defining a gravitational singularity as an obstruction to the dynamical evolution of a test field (described by a PDE) rather than the dynamical evolution of a particle (described by a geodesics) is explored. In particular, the concept of wave regularity is introduced which serves to show that the classical singularities in curve integrable spacetimes do not interrupt the well-posedness of the wave equation. The techniques used also provide arguments that can be extended to establish when a classically singular spacetime remains singular in a semi-classical picture.

Yafet Sanchez Sanchez

2015-02-23T23:59:59.000Z

214

Decline curve analysis for horizontal wells  

E-Print Network [OSTI]

support kept me from losing sight of my goals. Thanks to Sam Hou, Joseph Wang, Robert Liau, James Wang, and Shou for their company and in particular to Li Fan and Mrs. Shou-Lee Chang for their caring and delicious meals when I forgot my dinner. Thanks... Pressure (L/2xe= 0. 2) Composite Dimensionless Flow Rate Integral and Flow Rate Integral Derivative Functions Type Curve for an Infinite-Conductivity Horizontal Well Located in the Center of a Square Drainage Area, Producing at Constant Bottomhole...

Shih, Min-Yu

1994-01-01T23:59:59.000Z

215

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

216

Algebraic quantum field theory in curved spacetimes  

E-Print Network [OSTI]

This article sets out the framework of algebraic quantum field theory in curved spacetimes, based on the idea of local covariance. In this framework, a quantum field theory is modelled by a functor from a category of spacetimes to a category of ($C^*$)-algebras obeying supplementary conditions. Among other things: (a) the key idea of relative Cauchy evolution is described in detail, and related to the stress-energy tensor; (b) a systematic "rigidity argument" is used to generalise results from flat to curved spacetimes; (c) a detailed discussion of the issue of selection of physical states is given, linking notions of stability at microscopic, mesoscopic and macroscopic scales; (d) the notion of subtheories and global gauge transformations are formalised; (e) it is shown that the general framework excludes the possibility of there being a single preferred state in each spacetime, if the choice of states is local and covariant. Many of the ideas are illustrated by the example of the free Klein-Gordon theory, which is given a new "universal definition".

Christopher J. Fewster; Rainer Verch

2015-04-02T23:59:59.000Z

217

Effect of laser shock processing (LSP) on the fatigue resistance of an aluminum alloy  

SciTech Connect (OSTI)

The laser shock induced stress wave is described and measured with a polyvinylidene fluoride (PVDF) transducer. A principle for selecting laser parameters is proposed. A small sized laser with a high power is used for Laser Shock Processing (LSP). The fatigue life of the aluminum alloy 2024T62 is greatly improved after LSP. With 95% confidence, the mean fatigue life of LSP specimens is 4.5--9.8 times that of unshocked ones. The fatigue and fracture resistance mechanisms of LSP such as the variation of the surface hardness, the microstructure and the fracture section of specimens before and after LSP are analyzed.

Yaxin, T.; Yongkang, Z.; Hong, Z.; Chengye, Y.

2000-01-01T23:59:59.000Z

218

Cement fatigue and HPHT well integrity with application to life of well prediction  

E-Print Network [OSTI]

to the cyclic loading and few data sets may not be sufficient to give an adequate description of cement behavior under fatigue loading. Studies were conducted by Kim and Kim 2 on the fatigue behavior of high strength concrete using a type I Portland cement....3: Comparison of Max Stress Levels to Number of Cycles for Different Cement Strengths [2] Antrim 3 conducted fatigue studies on hardened ordinary Portland (type I) cement paste using 2 specimens; one with a high-water cement ratio of 0.7 and another...

Ugwu, Ignatius Obinna

2009-05-15T23:59:59.000Z

219

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

220

O set Approximation Improvment G. Elber and E. Cohen 10 9] J. Hoschek and N .Wissel. Optimal approximate conversion of spline curves and  

E-Print Network [OSTI]

. Journal de Mathematique Pures et Appliquees, 15 (1850), 332-350. 3] B .Cobb Design of Sculptured Surfaces. Elber and E. Cohen 8 Figure 4: The error function does not convergence to zero, for general curves. Step

Utah, University of

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

Physical modeling of the soil swelling curve vs. the shrinkage curve  

E-Print Network [OSTI]

Physical understanding of the links between soil swelling, texture, structure, cracking, and sample size is of great interest for the physical understanding of many processes in the soil-air-water system and for applications in civil, agricultural, and environmental engineering. The background of this work is an available chain of interconnected physical shrinkage curve models for clay, intra-aggregate matrix, aggregated soil without cracks, and soil with cracks. The objective of the work is to generalize these models to the case of swelling, and to construct the physical-swelling-model chain with a step-by-step transition from clay to aggregated soil with cracks. The generalization is based on thorough accounting for the analogies and differences between shrinkage and swelling and the corresponding use, modification, or replacement of the soil shrinkage features. Two specific soil swelling features to be used are: (i) air entrapping in pores of the contributing clay; and (ii) aggregate destruction with the formation of new aggregate surfaces. The input for the prediction of the swelling curve of an aggregated soil coincides with that of the available model of the shrinkage curve. The analysis of available data on the maximum shrink-swell cycle of two soils with different texture and structure, accounting for sample size is conducted as applied to swelling curves and to the residual crack volume and maximum-swelling-volume decrease after the shrink-swell cycle. Results of the analysis show evidence in favor of the swelling model chain.

V. Y. Chertkov

2014-04-14T23:59:59.000Z

222

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

223

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

224

The crystallography of fatigue crack initiation in Incoloy-908 and A-286 steel  

SciTech Connect (OSTI)

Fatigue crack initiation in the austenitic Fe-Ni superalloys Incoloy-908 and A-286 is examined using local crystallographic orientation measurements. Results are consistent with sharp transgranular initiation and propagation occurring almost exclusively on {l_brace}111{r_brace} planes in Incoloy-908 but on a variety of low index planes in A-286. This difference is attributed to the influence of the semicoherent grain boundary {eta} phase in A-286. Initiation in each alloy occurred both intergranularly and transgranularly and was often associated with blocky surface oxide and carbide inclusions. Taylor factor and resolved shear stress and strain crack initiation hypotheses were tested, but despite an inconclusive suggestion of a minimum required {l_brace}111{r_brace} shear stress, none of the hypotheses were found to convincingly describe preferred initiation sites, even within the subsets of transgranular cracks apparently free from the influence of surface inclusions. Subsurface inclusions are thought to play a significant role in crack initiation. These materials have applications for use in structural conduit for high field superconducting magnets designed for fusion energy use.

Krenn, C.R. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley National Lab., CA (United States)

1996-12-01T23:59:59.000Z

225

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

226

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

227

FATIGUE OF SKIN-STIFFENER INTERSECTIONS IN COMPOSITE WIND TURBINE BLADE STRUCTURES  

E-Print Network [OSTI]

FATIGUE OF SKIN-STIFFENER INTERSECTIONS IN COMPOSITE WIND TURBINE BLADE STRUCTURES by Robert B in the Instron and Composite Laboratories toward the end of the experimental research. Finally, special thanks

228

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

229

Fatigue behavior of full-size soild-sawn timber railroad stringers  

E-Print Network [OSTI]

As part of the Timber Bridge Life Extension Program sponsored by the Association of American Railroads (AAR), the objective of this thesis is to investigate the fatigue behavior of large solid-sawn timber beams. Specifically, the main flexural...

Maingot, Martin Rex

1999-01-01T23:59:59.000Z

230

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

231

Stochastic Damage Evolution under Static and Fatigue Loading in Composites with Manufacturing Defects  

E-Print Network [OSTI]

In this dissertation, experimental investigations and theoretical studies on the stochastic matrix cracking evolution under static and fatigue loading in composite laminates with defects are presented. The presented work demonstrates a methodology...

Huang, Yongxin

2012-07-16T23:59:59.000Z

232

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

E-Print Network [OSTI]

steels and free-cutting steels Part 17: ball and roller bearing steels, Technical Report 68317:1999, International Organization for Standardization, 1991. [11] D. Glover, in: Rolling Contact Fatigue Testing of Bearing Steels, volume 771 of ASTM STP...

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

2014-04-13T23:59:59.000Z

233

Effect of nano-scale twinning on the fracture, fatigue and wear properties of copper  

E-Print Network [OSTI]

Grain refinement in materials has been one of the most common strategies for improving the strength of materials. However this comes at the price of reduced ductility, fracture toughness and stable fatigue crack propagation ...

Singh, Aparna, Ph.D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

234

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

235

E-Print Network 3.0 - auditory fatigue Sample Search Results  

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

08 February 2010 Summary: Department Fatigue failure theories Stress analysis Shaft and rotor of a turbine CAE model of shaft T T R1 R2... w W 12;Mechanical Engineering...

236

The effectiveness of floor mats as an intervention for standing fatigue of light fabrication workers  

E-Print Network [OSTI]

A field study was conducted in a light fabrication plant to determine the effectiveness of floor mats on reducing the symptoms of standing fatigue. Specific physiological variables measured include skin temperature of the foot, blood pooling...

O'Brien, Michael Shannon

1996-01-01T23:59:59.000Z

237

Transformation Induced Fatigue of Ni-Rich NiTi Shape Memory Alloy Actuators  

E-Print Network [OSTI]

In this work the transformation induced fatigue of Ni-rich NiTi shape memory alloys (SMAs) was investigated. The aerospace industry is currently considering implementing SMA actuators into new applications. However, before any new applications can...

Schick, Justin Ryan

2011-02-22T23:59:59.000Z

238

Influence of microstructure on near-threshold fatigue-crack propagation  

E-Print Network [OSTI]

in turbine rotor shafts 1 and acoustic fatigue of welds in gas ducts in magnox reactors.1, 2 The application behaviour at higher growth rates. A semi- quantitative model is developed to rationalize near- threshold

Ritchie, Robert

239

SciTech Connect: Prediction of the Creep-Fatigue Lifetime of...  

Office of Scientific and Technical Information (OSTI)

approach would be relevant to calculate the remaining useful life to a component like a steam generator that might fail by the creep-fatigue mechanism. Authors: Vivek Agarwal;...

240

Static and fatigue bending behavior of pultruded GFRP sandwich panels with through-thickness fiber insertions  

E-Print Network [OSTI]

to evaluate the static and fatigue characteristics of an innovative 3-D glass fiber reinforced polymer (GFRP materials typically include polymeric foams, balsa wood, light- weight honeycomb structures or FRP shear

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

SUPERNOVA LIGHT CURVES POWERED BY FALLBACK ACCRETION  

SciTech Connect (OSTI)

Some fraction of the material ejected in a core collapse supernova explosion may remain bound to the compact remnant, and eventually turn around and fall back. We show that the late time ({approx}>days) power potentially associated with the accretion of this 'fallback' material could significantly affect the optical light curve, in some cases producing super-luminous or otherwise peculiar supernovae. We use spherically symmetric hydrodynamical models to estimate the accretion rate at late times for a range of progenitor masses and radii and explosion energies. The accretion rate onto the proto-neutron star or black hole decreases as M-dot {proportional_to}t{sup -5/3} at late times, but its normalization can be significantly enhanced at low explosion energies, in very massive stars, or if a strong reverse shock wave forms at the helium/hydrogen interface in the progenitor. If the resulting super-Eddington accretion drives an outflow which thermalizes in the outgoing ejecta, the supernova debris will be re-energized at a time when photons can diffuse out efficiently. The resulting light curves are different and more diverse than previous fallback supernova models which ignored the input of accretion power and produced short-lived, dim transients. The possible outcomes when fallback accretion power is significant include super-luminous ({approx}> 10{sup 44} erg s{sup -1}) Type II events of both short and long durations, as well as luminous Type I events from compact stars that may have experienced significant mass loss. Accretion power may unbind the remaining infalling material, causing a sudden decrease in the brightness of some long duration Type II events. This scenario may be relevant for explaining some of the recently discovered classes of peculiar and rare supernovae.

Dexter, Jason; Kasen, Daniel, E-mail: jdexter@berkeley.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)

2013-07-20T23:59:59.000Z

242

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

243

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

244

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

245

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

246

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

247

Construction of Fractal Surfaces by Recurrent Fractal Interpolation Curves  

E-Print Network [OSTI]

A method to construct fractal surfaces by recurrent fractal curves is provided. First we construct fractal interpolation curves using a recurrent iterated functions system(RIFS) with function scaling factors and estimate their box-counting dimension. Then we present a method of construction of wider class of fractal surfaces by fractal curves and Lipschitz functions and calculate the box-counting dimension of the constructed surfaces. Finally, we combine both methods to have more flexible constructions of fractal surfaces.

Chol-hui Yun; Hyong-chol O.; Hui-chol Choi

2014-08-12T23:59:59.000Z

248

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

249

Comparison of operating speeds at spiral transition and circular curves  

E-Print Network [OSTI]

acceleration, fijs; and V = speed, mph In evaluating the models, it was found that the spiral length increases with increasing speed, but does not become unreasonably long. It was also found that the spiral length and spiral ang e epen o y on 1 d d nl... curves provide deceptive information to drivers is based on crash data for spiral curves, he does not present data for comparable circular curves In addition, the issue of whether the spiral curve is causing the crashes or whether crash rates...

Passetti, Karl Andrew

1998-01-01T23:59:59.000Z

250

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

251

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

252

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

253

Instanton effects and quantum spectral curves  

E-Print Network [OSTI]

We study a spectral problem associated to the quantization of a spectral curve arising in local mirror symmetry. The perturbative WKB quantization condition is determined by the quantum periods, or equivalently by the refined topological string in the Nekrasov-Shatashvili (NS) limit. We show that the information encoded in the quantum periods is radically insufficient to determine the spectrum: there is an infinite series of instanton corrections, which are non-perturbative in \\hbar, and lead to an exact WKB quantization condition. Moreover, we conjecture the precise form of the instanton corrections: they are determined by the standard or un-refined topological string free energy, and we test our conjecture successfully against numerical calculations of the spectrum. This suggests that the non-perturbative sector of the NS refined topological string contains information about the standard topological string. As an application of the WKB quantization condition, we explain some recent observations relating membrane instanton corrections in ABJM theory to the refined topological string.

Johan Kallen; Marcos Marino

2014-04-16T23:59:59.000Z

254

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

255

Kummel Disease Treatment by Unipedicular Vertebral Augmentation Using Curved Injection Cannula  

SciTech Connect (OSTI)

Purpose: This study was designed to evaluate the efficacy of the blunt-tipped curved injection needle (BCN) AVAflex (Care Fusion) for vertebral augmentation in cases of Kummel's disease. Methods: We performed 25 vertebral augmentation procedures on 25 consecutive patients (11 men/14 women; mean age, 67 years) with Kummel's disease using the blunt-tipped curved injection needle with PMMA cement. We performed all 25 procedures by unipedicular left approach with patients in prone position under local anesthesia and mild sedation. In all cases, an intravertebral cleft was evident on preprocedural imaging. We evaluated pain intensities by Visual Analogic Scale (VAS) before and at first day, 6 months, and 1 year after procedure. Results: In all cases the curved injection cannula permitted the filling of the clefts and surrounding cancellous bone without any complication. A significant reduction of kyphotic deformities of the treated vertebral bodies was evident. A significance decrease in VAS values at 1 year also was evident (mean decrease 7.2). At plain dynamic postprocedural X-rays checks, there was no sign of pathologic intravertebral motion as evidence of optimal stabilization. Conclusions: BCN AVAflex is a safe and effective device for targeted vertebral augmentation in cases of Kummel's disease. Its distinctive characteristic is the curved injection cannula, which enables targeting the cement injection to areas far off the trajectory of the straight access cannula, thus providing excellent cement spread throughout the entire volume of vertebral body.

Masala, Salvatore, E-mail: salva.masala@tiscali.it; Nano, Giovanni; Mammucari, Matteo; Simonetti, Giovanni [University 'Tor Vergata', Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy (Italy)

2011-10-15T23:59:59.000Z

256

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

257

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

E-Print Network [OSTI]

details of orthotropic steel deck. Proc. , Internationalnew approaches to fatigue evaluation of steel bridges. International Journal of Steel Structures, KSSC, Vol. 6, No.

Sim, Hyoung-Bo

2010-01-01T23:59:59.000Z

258

Preliminary design of centrifugal compressors  

SciTech Connect (OSTI)

Preliminary design calculations are analyzed for a centrifugal compressor, after choosing as the type of the turbomachine from the curves given by Balje (1981). In impeller calculations, the effect of slip factor on exit conditions, the inducer geometry and the effect of choked flow on relative Mach number are investigated. In discharge calculation vaned diffusers are compared with vaneless diffusers.

Kocak, S. [Selcuk Univ., Konya (Turkey). Dept. of Mechanical Engineering

1996-11-01T23:59:59.000Z

259

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

E-Print Network [OSTI]

be ordered by ISSO. http://www.isso.nl/ Elkhuizen P.A. , Peitsman H.C., ? A new design guideline for the heating and cooling curve in AHU of HVAC systems (a method for the optimal adjustment of AHU in HVAC systems) ?, A40-E-M4-NL-TNO-1, IEA Annex 40...

2004-01-01T23:59:59.000Z

260

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.

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.


261

THE ECONOMICS OF CONSERVED-ENERGY "SUPPLY" CURVES  

E-Print Network [OSTI]

PWP-028 THE ECONOMICS OF CONSERVED-ENERGY "SUPPLY" CURVES Steven Stoft April 1995 This paper Berkeley, California 94720-5180 www.ucei.berkeley.edu/ucei #12;PWP-028 THE ECONOMICS OF CONSERVED-ENERGY "SUPPLY" CURVES Steven Stoft April 1995 #12;Table of Contents The Economics of Conserved-Energy "Supply

California at Berkeley. University of

262

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

263

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

264

The Dimension of the SLE Curves Vincent BEFFARA  

E-Print Network [OSTI]

generating a Schramm-Loewner Evolution (SLE) process, with parameter 0: We prove that, with probability one (Kt) is generated by a random curve : [0, ) H (called the trace of the SLE or the SLE curve clusters) and = 8/3 (this follows from the description of the outer frontier of SLE6 -- or planar Brownian

Beffara, Vincent

265

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

266

CURVES OF GENUS 2 WITH p 2 MULTIPLICATION  

E-Print Network [OSTI]

thesis, which looks at curves of genus 2 whose jacobians have p 2 multiplication, with the generalisedCURVES OF GENUS 2 WITH p 2 MULTIPLICATION PETER R. BENDING Abstract We give a universal family, and let f be a newform on \\Gamma 1 (N) whose field of Fourier coefficients is F (F is a totally real field

267

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

268

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@ramboll.com ABSTRACT It is investigated if material based structural safety can be replaced with safety obtained from of the NREL 5MW wind turbine tower subjected to bending fatigue and horizontal circumferential cracking

Boyer, Edmond

269

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

270

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

E-Print Network [OSTI]

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

Barber, James R.

271

Temperature dependence of strength and fatigue of fused silica fiber in the range 77 to 473 K  

E-Print Network [OSTI]

the inert strength, i. e. the starting strength of the material before degradation by fatigue. Published between environmental moisture and strained bonds in the region of stress amplifying surface defects suggesting that fatigue still proceeds at low temperature. Duncan et al.5 measured the strength of silicone

Matthewson, M. John

272

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

273

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

274

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

275

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

276

Corrosion-fatigue behavior of an annealed AISI 1045 carbon steel coated with electroless nickel-phosphorus  

SciTech Connect (OSTI)

The influence of an industrial electroless nickel-phosphorus deposit on the corrosion-fatigue properties of an annealed AISI 1045 steel has been investigated. For this purpose, three corrosive media were selected: distilled water and two NaCl solutions of different concentration (3 and 5%) in distilled water. Corrosion-fatigue tests were conducted at alternating stress levels ranging between 219 and 329 MPa at a frequency of 50 Hz. The corrosion-fatigue properties of the coated and uncoated substrates are very similar when testing is conducted in salty water. However, for testing in distilled water the corrosion-fatigue properties of coated substrates were diminished in relation to the uncoated material. The fractographic analysis of the fracture surfaces revealed the presence of fatigue marks within the electroless nickel-phosphorus deposit, which indicate that the fracture mechanism of the coating is associated to the cyclic loading of the material.

Pertuz, A.; Chitty, J.A.; Puchi, E.S. (Central Univ. of Venezuela, Caracas (Venezuela)); Hintermann, H. (Univ. of Neuchatel (Switzerland). Faculty of Sciences)

1999-08-01T23:59:59.000Z

277

Exhaustive search system and method using space-filling curves  

DOE Patents [OSTI]

A search system and method for one agent or for multiple agents using a space-filling curve provides a way to control one or more agents to cover an area of any space of any dimensionality using an exhaustive search pattern. An example of the space-filling curve is a Hilbert curve. The search area can be a physical geography, a cyberspace search area, or an area searchable by computing resources. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace.

Spires, Shannon V.

2003-10-21T23:59:59.000Z

278

Application of the decline curve method to aquifers  

E-Print Network [OSTI]

k = value of pointin time = value of point in time n = value of point in time 39 REFERENCES 1. Fetkovich, M. J. : "Decline Curve Analysis Using Type Curves, " JPT (June 1980) 1065-1077. 2. Havlena, D. and Odeh, A. S. : "The Material Balance...APPLICATION OF THE DECLINE CURVE METHOD TO AQUIFERS A Thesis by GIRISH VIJAY POTNIS Submitted to the Office of Graduate Studies of Texas ADAM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December...

Potnis, Girish Vijay

1992-01-01T23:59:59.000Z

279

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

1982-01-01T23:59:59.000Z

280

Fatigue Behaviour of Magnesium to Steel Dissimilar Friction Stir Lap Joints  

SciTech Connect (OSTI)

A short study has been conducted to assess the performance of friction stir welded Mg/steel joints under dynamic loads. The major mode of failure was found to be top Mg sheet fracture. Crack initiation is noted to have taken place at the Mg/steel interface. The fatigue life of the joints is found to be significantly different than the fatigue data of the Mg alloy obtained from the literature. The reasons behind such a difference have been examined in this work.

Jana, Saumyadeep; Hovanski, Yuri

2012-02-01T23:59:59.000Z

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.


281

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

282

Simulation and Experiment of Thermal Fatigue in the CPV Die Attach: Preprint  

SciTech Connect (OSTI)

FEM simulation and accelerated thermal cycling have been performed for the CPV die attach. Trends in fatigue damage accumulation and equivalent test time are explored and found to be most sensitive to temperature ramp rate. Die attach crack growth is measured through cycling and found to be in excellent agreement with simulations of the inelastic strain energy accumulated. Simulations of an entire year of weather data provides for the relative ranking of fatigue damage between four cites as well as their equivalent accelerated test time.

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

2012-05-01T23:59:59.000Z

283

Materials degradation and fatigue under extreme conditions. Final report, 1 April 1994-31 August 1997  

SciTech Connect (OSTI)

This AFOSR URI addressed complex research problems of materials degradation and fatigue in aerospace structures in severe or extreme environments. A better understanding of materials degradation and flaw initiation dynamics was achieved through a multi-disciplinary research program encompassing chemistry, surface physics, materials science and mechanics, both experimental and theoretical. The Subprojects were as follows: (1) Surface Induced Degradation of Fluorocarbon Lubricants; (2) Molecular Tribology of Perfluoroether Lubricants; (3) Fluids, Including Lubricants Under Extreme Conditions of High Pressure/High Temperature and Confinement; (4) Surface Crack Propagation Under Combined Mechanical and High Pressure Fluid Loading; and (5) Lubricant Assisted Fatigue Crack Growth in Ceramics.

Jonas, J.

1997-10-29T23:59:59.000Z

284

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

285

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

286

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

287

Physical modeling of the soil swelling curve vs. the shrinkage curve  

E-Print Network [OSTI]

Physical understanding of the links between soil swelling, texture, structure, cracking, and sample size is of great interest for the physical understanding of many processes in the soil-air-water system and for applications in civil, agricultural, and environmental engineering. The background of this work is an available chain of interconnected physical shrinkage curve models for clay, intra-aggregate matrix, aggregated soil without cracks, and soil with cracks. The objective of the work is to generalize these models to the case of swelling, and to construct the physical-swelling-model chain with a step-by-step transition from clay to aggregated soil with cracks. The generalization is based on thorough accounting for the analogies and differences between shrinkage and swelling and the corresponding use, modification, or replacement of the soil shrinkage features. Two specific soil swelling features to be used are: (i) air entrapping in pores of the contributing clay; and (ii) aggregate destruction with the f...

Chertkov, V Y

2014-01-01T23:59:59.000Z

288

Knowledge fusion: Comparison of fuzzy curve smoothers to statistically motivated curve smoothers  

SciTech Connect (OSTI)

This report describes work during FY 95 that was sponsored by the Department of Energy, Office of Nonproliferation and National Security (NN) Knowledge Fusion (KF) Project. The project team selected satellite sensor data to use as the one main example to which its analysis algorithms would be applied. The specific sensor-fusion problem has many generic features, which make it a worthwhile problem to attempt to solve in a general way. The generic problem is to recognize events of interest from multiple time series that define a possibly noisy background. By implementing a suite of time series modeling and forecasting methods and using well-chosen alarm criteria, we reduce the number of false alarms. We then further reduce the number of false alarms by analyzing all suspicious sections of data, as judged by the alarm criteria, with pattern recognition methods. This report gives a detailed comparison of two of the forecasting methods (fuzzy forecaster and statistically motivated curve smoothers as forecasters). The two methods are compared on five simulated and five real data sets. One of the five real data sets is satellite sensor data. The conclusion is the statistically motivated curve smoother is superior on simulated data of the type we studied. The statistically motivated method is also superior on most real data. In defense of the fuzzy-logic motivated methods, we point out that fuzzy-logic methods were never intended to compete with statistical methods on numeric data. Fuzzy logic was developed to handle real-world situations where either real data was not available or was supplemented with either ``expert opinion`` or some sort of linguistic information.

Burr, T.; Strittmatter, R.B.

1996-03-01T23:59:59.000Z

289

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

290

Optimization of the Collection Efficiency of a Hexagonal Light Collector using Quadratic and Cubic Bzier Curves  

E-Print Network [OSTI]

Reflective light collectors with hexagonal entrance and exit apertures are frequently used in front of the focal-plane camera of a very-high-energy gamma-ray telescope to increase the collection efficiency of atmospheric Cherenkov photons and reduce the night-sky background entering at large incident angles. The shape of a hexagonal light collector is usually based on Winston's design, which is optimized for only two-dimensional optical systems. However, it is not known whether a hexagonal Winston cone is optimal for the real three-dimensional optical systems of gamma-ray telescopes. For the first time we optimize the shape of a hexagonal light collector using quadratic and cubic B\\'ezier curves. We demonstrate that our optimized designs simultaneously achieve a higher collection efficiency and background reduction rate than traditional designs.

Akira Okumura

2012-06-04T23:59:59.000Z

291

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

292

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

293

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

294

Multiobjective Design and Optimization of Polymer Flood Performance  

E-Print Network [OSTI]

The multiobjective genetic algorithm can be used to optimize two conflicting objectives, oil production and polymer utility factor in polymer flood design. This approach provides a set of optimal solutions which can be considered as trade-off curve...

Ekkawong, Peerapong

2013-07-22T23:59:59.000Z

295

Determination of the Price-Load Curve by Using Smoothing Splines Under Tension  

E-Print Network [OSTI]

Determination of the Price-Load Curve by Using Smoothing Splines Under Tension Master Thesis 4.2. Price-Load Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4 load and price . . . . . . . . . . . . . . . . . . . . . . 6 1.5. Merit order curve with operating

296

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

297

Fatigue and Overloading Behavior of SteelConcrete Composite Flexural Members Strengthened with High  

E-Print Network [OSTI]

strengthened with new high modulus carbon fiber-reinforced polymer HM CFRP materials. The behavior of the beams.1061/ ASCE 1090-0268 2007 11:6 659 CE Database subject headings: Fatigue; Composite materials; Fiber carbon FRP CFRP materials for the repair and strength- ening of steel bridges and structures. A number

298

Influence of Nonlinear Irregular Waves on the Fatigue Loads of an Offshore Wind Turbine  

E-Print Network [OSTI]

Influence of Nonlinear Irregular Waves on the Fatigue Loads of an Offshore Wind Turbine Michiel B. van der Meulen1, Turaj Ashuri2, Gerard J.W. van Bussel3 and David P. Molenaar1 1 Offshore Center-mail: michiel van.der.meulen@siemens.com Abstract. In order to make offshore wind power a cost effective

Papalambros, Panos

299

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

300

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

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

International Journal of Fatigue 21 (1999) 725731 www.elsevier.com/locate/ijfatigue  

E-Print Network [OSTI]

performance materials subject to severe operating conditions in the high temperature turbine section of gas fatigue crack propagation behavior of a nickel-base turbine disk alloy S.A. Padula II a , A. Shyam a , R turbine engines. Turbine blades in modern engines are fabricated from Ni-base alloy single crystals which

Ritchie, Robert O.

302

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

303

Thermo-optical modulation for improved ultrasonic fatigue crack detection in Ti6Al4V  

E-Print Network [OSTI]

scatterers, such as surface grooves, corrosion pits, coarse grains, etc. that might hide the fatigue crack to grow at unexpectedly high growth rates well below the large-crack threshold in aluminum, aluminumlithium) and secondary irregulari- ties (e.g. uneven machining, mechanical wear, corrosion, etc.). Second

Nagy, Peter B.

304

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

305

Graphene coating makes carbon nanotube aerogels superelastic and resistant to fatigue  

E-Print Network [OSTI]

Graphene coating makes carbon nanotube aerogels superelastic and resistant to fatigue Kyu Hun Kim-based foams10­14 and aero- gels15,16 . However, all nanotube-based foams and aerogels devel- oped so far10,11,13,14 when they are subjected to cyclic strain. Here, we show that an inelastic aerogel made

McGaughey, Alan

306

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

307

Contact fatigue behavior and gas cell thermal wave NDE of sintered reaction bonded silicon nitride  

SciTech Connect (OSTI)

Silicon nitride is being evaluated for potential applications as structural components subjected to contact fatigue loading. A new testing and evaluation methodology for evaluation of Hertzian contact fatigue damage in ceramic materials has been developed and is described. Contact fatigue damage is induced in three test specimens simultaneously. The material investigated is Eaton Corporation`s low cost E - Process Silicon Nitride. Tests were conducted at several Hertzian stress levels to evaluate contact fatigue damage behavior. Gas cell thermal wave NDE was employed to study the induced subsurface damage. Damage behavior was also investigated using optical microscopy. Two specimens were evaluated in detail; one that was tested for 17,400 cycles, P{sub max} = 2700 N and one that was tested for 1 x 10{sup 6} cycles, P{sub max} = 1800 N. The 2700 N specimen has a partial cone crack and contains a small concentration of vertical and shallow horizontal cracks. No evidence of a cone crack was detected on the 1800 N specimen. However, a larger concentration of horizontal microcracks at and just below the surface is present in this specimen, with particle debris in and around the surface contact area. Correlation of the optical microscopy observations with gas cell thermal wave NDE of the subsurface damage in these two specimens is discussed.

Barla, J.R.; Edler, J.P.; Lin, H. [Eaton Corp. R & D, Southfield, MI (United States)] [and others

1996-12-31T23:59:59.000Z

308

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

309

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

310

Submitted to the International Journal of Fatigue, June 2005 Revised, May 2006  

E-Print Network [OSTI]

specimen under mechanical cyclic loadings. The results of so-called "heating tests" (i.e., thermal effects [7, 8] or infrared (IR) cameras [2-6]. If the dissipated energy is induced by microplasticity, which-cycle fatigue (HCF) failure is caused by microplasticity, correlation between the two tests (i.e., "heating test

311

Cavitation Fatigue. Embolism and Refilling Cycles Can Weaken the Cavitation Resistance of Xylem1  

E-Print Network [OSTI]

Cavitation Fatigue. Embolism and Refilling Cycles Can Weaken the Cavitation Resistance of Xylem1Culloh Department of Biology, University of Utah, Salt Lake City, Utah 84112 Although cavitation and refilling cycles could be common in plants, it is unknown whether these cycles weaken the cavitation resistance

Stiller, Volker

312

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

313

Elevated temperature static fatigue of a Nicalon fiber-reinforced SiC composite  

SciTech Connect (OSTI)

Static fatigue tests of a Nicalon fiber-reinforced SiC matrix composite were conducted in four-point bending over a temperature range of 425 to 1,150 C in air at selected stress levels. The composite consisted of a Nicalon cloth with a 0.3 {mu}m graphite interfacial coating and a Forced Chemical Vapor Infiltration (FCVI) SiC matrix composite; samples were tested with or without a final protective SiC seal coat. The results indicated that the fatigue life of the Nicalon-SiC composite decreased with an increase in either applied stresses or test temperatures. However, the composite exhibited a fatigue limit of {approximately} 100 MPa at temperatures < 950 C which decreased to {approximately} 70 MPa at 1,150 C. Both electron microscopy and thermogravimetric studies suggested that the lifetime of the composites was dictated by the oxidation of graphite interfacial layer at temperatures {le} 700 C and by oxidation of graphite coating accompanied by formation of silicate interfacial layer via oxidation of the Nicalon fiber (and the SiC matrix) at temperatures {ge} 950 C. Use of a SiC seal coat effectively retarded the oxidation reactions and increased the lifetime by at least one order of magnitude at 425 C. On the other hand, the SiC seal coat made little (if any) difference in fatigue life at 950 C.

Lin, H.T.; Becher, P.F.; Tortorelli, P.F. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1994-12-31T23:59:59.000Z

314

Determination of torsional fatigue life of large turbine generator shafts. Final report  

SciTech Connect (OSTI)

This report presents the results of a study to develop a methodology for predicting torsional fatigue damage to a turbine generator rotor subjected to transient electrical disturbances. This methodology used torsional properties obtained from constant amplitude tests on one-inch diameter specimens. The predictions were verified with constant amplitude and variable amplitude tests of specimens up to six inches in diameter.

Placek, R.J.; Williams, R.A.; Adams, S.L.; Klufas, O.

1984-04-01T23:59:59.000Z

315

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

316

Influence of Hold Time on Creep-Fatigue Behavior of an Advanced Austenitic Alloy  

SciTech Connect (OSTI)

An advanced austenitic alloy, HT-UPS (high temperature-ultrafine precipitate strengthened), is a candidate material for the structural components of fast reactors and energy-conversion systems. HT-UPS provides improved creep resistance through a composition based on 316 stainless steel (SS) with additions of Ti and Nb to form nano-scale MC precipitates in the austenitic matrix. The low cycle fatigue and creep-fatigue behavior of a HT-UPS alloy has been investigated at 650 C, 1.0% total strain, and an R ratio of -1 with hold times as long as 9000 sec at peak tensile strain. The cyclic deformation response of HT-UPS is compared to that of 316 SS. The cycles to failure are similar, despite differences in peak stress profiles and the deformed microstructures. Cracking in both alloys is transgranular (initiation and propagation) in the case of continuous cycle fatigue, while the primary cracks also propagate transgranularly during creep-fatigue cycling. Internal grain boundary damage as a result of the tensile hold is present in the form of fine cracks for hold times of 3600 sec and longer and substantially more internal cracks are visible in 316 SS than HT-UPS. The dislocation substructures observed in the deformed material are different. An equiaxed cellular structure is observed in 316 SS, whereas tangles of dislocations are present at the nanoscale MC precipitates in HT-UPS and no cellular substructure is observed.

Mark Carroll; Laura Carroll

2011-09-01T23:59:59.000Z

317

RIS-R-1358(EN) Accelerated Fatigue Testing of LM 19.1  

E-Print Network [OSTI]

May 2003 #12;Abstract A series of 19.1 metre wind turbine blades manufactured by LM Glasfiber A with thermal imaging equipment to determine how an increase in fatigue load affects the blade material FOR STRAIN GAUGES 71 RIS-R-1358(EN)4 #12;1 Introduction Traditionally a wind turbine blade is tested as part

318

SOL-XX-XXXX, Samborsky,1 Comparison of Tensile Fatigue Resistance and Constant Life  

E-Print Network [OSTI]

for Several Potential Wind Turbine Blade Laminates Daniel D. Samborsky* , Timothy J. Wilson, and John F and potential interest for wind turbine blades, representing three types of fibers: E-glass, WindStrandTM glass are then used to predict the performance under spectrum fatigue loading relative to an earlier material

319

2013 AIAA SDM Wind Energy Session Creep/Fatigue Behavior of Resin Infused Biaxial Glass  

E-Print Network [OSTI]

/epoxy biaxial (45o ) fabric laminates typical of shell/web areas of wind blades. Loading conditions were cyclic in the shell. Thus, the biaxial materials must resist the maximum blade strains under static and fatigue loads without failure or softening enough to reduce the blade stiffness or overload adjacent UD material

320

In: Fatigue Crack Growth... Editor: Alphonse F. Lignelli, pp. 3-48  

E-Print Network [OSTI]

fatigue test apparatus, equipped with ultrasonic sensors and an optical microscope, has been used sensing technique that is sensitive to small microstructural changes, robust to measurement noise-state machine that captures the dynamical system behavior by information compression. A computer-controlled

Ray, Asok

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

Online fatigue damage monitoring by ultrasonic measurements: A symbolic dynamics approach q  

E-Print Network [OSTI]

experimentally validated on a special-purpose test apparatus that is equipped with ultrasonic flaw detectionOnline fatigue damage monitoring by ultrasonic measurements: A symbolic dynamics approach q Shalabh alloy specimens, where the experiments have been conducted under load-controlled constant amplitude sinu

Ray, Asok

322

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

323

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

324

Analysis and detection of driver fatigue caused by sleep deprivation  

E-Print Network [OSTI]

Human errors in attention and vigilance are among the most common causes of transportation accidents. Thus, effective countermeasures are crucial for enhancing road safety. By pursuing a practical and reliable design of ...

Yang, Ji Hyun, 1978-

2007-01-01T23:59:59.000Z

325

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

326

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

327

Abstract--this paper proposes a MIMO linear quadratic regulator (LQR) controller designed for a horizontal variable  

E-Print Network [OSTI]

industry offers many challenges in designing effective wind turbines that will harness wind energy with the trade-off between the wind energy conversion maximization and the minimization of the fatigue delivery from a profoundly irregular primary source, the wind. The characteristics of the wind energy

Boyer, Edmond

328

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

329

EFFECT OF DARK MATTER HALO SUBSTRUCTURES ON GALAXY ROTATION CURVES  

SciTech Connect (OSTI)

In this paper, the effect of halo substructures on galaxy rotation curves is investigated using a simple model of dark matter clustering. A dark matter halo density profile is developed based only on the scale-free nature of clustering that leads to a statistically self-similar distribution of the substructures at the galactic scale. A semi-analytical method is used to derive rotation curves for such a clumpy dark matter density profile. It is found that the halo substructures significantly affect the galaxy velocity field. Based on the fractal geometry of the halo, this self-consistent model predicts a Navarro-Frenk-White-like rotation curve and a scale-free power spectrum of the rotation velocity fluctuations.

Roy, Nirupam, E-mail: nroy@aoc.nrao.ed [NRAO, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801 (United States)

2010-11-01T23:59:59.000Z

330

Light bullets in nonlinear periodically curved waveguide arrays  

SciTech Connect (OSTI)

We predict that stable mobile spatiotemporal solitons can exist in arrays of periodically curved optical waveguides. We find two-dimensional light bullets in planar arrays with harmonic waveguide bending and three-dimensional bullets in square lattices with helical waveguide bending using variational formalism. Stability of the light-bullet solutions is confirmed by the direct numerical simulations which show that the light bullets can freely move across the curved arrays. This mobility property is a distinguishing characteristic compared to previously considered discrete light bullets which were trapped to a specific lattice site. These results suggest new possibilities for flexible spatiotemporal manipulation of optical pulses in photonic lattices.

Matuszewski, Michal; Garanovich, Ivan L. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Sukhorukov, Andrey A. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Centre for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2010-04-15T23:59:59.000Z

331

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

332

The Fusion Curve of Ammonia and Ethyl Alcohol  

E-Print Network [OSTI]

Center for Digital Scholarship. http://kuscholarworks.ku.edu Submitted to the Graduate School of the University of Kansas for partial completion of Master of Arts. THE FUSION CURVE OF AMMONIA AND ETHYL ALCOHOL H. J. BRODERSON THE 2?03IOH CUHVB OP... AMMOHIA AND ETHXL ALCOHOL. A part of the requirement for the lh A. 2)egree. By K. J. Brodereon, University of Kangaa, May 1911, THE PUSIOB CURVS OP AliKOHlA AHD ETHYL ALCOHOL* Only within tho last fow ycara has any worlc boon done on tho fusion...

Broderson, H.J.

1911-01-01T23:59:59.000Z

333

The outer rotation curve of the Milky Way  

E-Print Network [OSTI]

A straightforward determination of the circular-speed curve vc(R) of the Milky Way suggests that near the Sun, vc starts to rise approximately linearly with R. If this result were correct, the Galactic mass density would have to be independent of radius at R ~> R0. We show that the apparent linear rise in v_c arises naturally if the true circular-speed curve is about constant or gently falling at R0 1.25 R0 are actually concentrated into a ring of radius ~1.6 R0.

James Binney; Walter Dehnen

1996-12-05T23:59:59.000Z

334

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

335

Simulated Fatigue Damage Index on Mooring Lines of a Gulf of Mexico Truss Spar Determined from Recorded Field Data  

E-Print Network [OSTI]

. The platform is equipped with an Environmental Platform Response Monitoring System (EPRMS) which records real-time motions, environmental parameters and loads. These measurements were used to hind-cast the platform mooring tensions and estimate fatigue damage...

Kiecke, Adam Fuller

2012-07-16T23:59:59.000Z

336

The effects of laser trimming on the tensile strength and fatigue resistance properties of titanium - 6Al-4V  

E-Print Network [OSTI]

The effect of laser trimming on the tensile strength and fatigue resistance of titanium-6% aluminum-4% vanadium specimens was investigated. Due to the nature of laser processing, the microstructure of the titanium alloy was altered in an area local...

Whitesel, Dean Adam

1994-01-01T23:59:59.000Z

337

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

338

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

339

The influence of high harmonic force on fatigue life and its prediction via coupled inline-crossflow VIV modeling  

E-Print Network [OSTI]

Vortex Induced Vibrations (VIV) of a flexibly mounted rigid cylinder placed in a flow is a canonical problem of fluid-structure interactions and the study of VIV and the resulting material fatigue is particularly important ...

Zheng, Haining

2014-01-01T23:59:59.000Z

340

Comptes Rendus des JNC 16 Toulouse 2009 Suivi de l'endommagement en fatigue des composites base de fibres  

E-Print Network [OSTI]

a thermoplastic matrix (Polypropylene) reinforced by short fibers (White Hemp and Chènevotte). This article fatigue / White Hemp / Acoustic emission / Stiffness loss/ hysteresis loops. hal-00429719,version1-4Nov

Paris-Sud XI, Université de

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

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

342

Four-Point Curve Subdivision Based on Iterated Chordal and Centripetal  

E-Print Network [OSTI]

Richter (Technical Computer Science) Prof. Dr. Gabriel Zachmann (Computer Graphics) #12;Four-Point Curve

Zachmann, Gabriel

343

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

344

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

345

Experience Curves and Solar PV Fred Heutte, Senior Policy Associate  

E-Print Network [OSTI]

Experience Curves and Solar PV Fred Heutte, Senior Policy Associate NW Energy Coalition September 3 resources costs as being ranges rather than fixed values. It is evident that the question of future solar PV small percentage of all resources at present, there is a strong sense that once solar PV reaches "grid

346

ISOMORPHISM CLASSES OF PICARD CURVES OVER FINITE FIELDS  

E-Print Network [OSTI]

for construction of cryptosystems based on the discrete logarithm problem, and elliptic curve cryptography is now for constructing public key cryptosystems by Galbraith, Paulus and Smart in [8]. Besides providing an algorithm, of a place p is defined as the extension degree of the residue field of p over k. For a divisor D = npp (that

347

type Riemannian metric on the space of planar curves  

E-Print Network [OSTI]

of Computational Anatomy (MFCA'06) inria-00635881,version1-26Oct2011 Author manuscript, published in "1st MICCAI (MFCA'06) 41 inria-00635881,version1-26Oct2011 #12;2.2 Closure of open curves in H1 metric A generic z

Paris-Sud XI, Universit de

348

The elliptic curve database to 130000 John Cremona  

E-Print Network [OSTI]

The elliptic curve database to 130000 John Cremona University of Nottingham, UK ANTS 7: Berlin, 26 July 2006 #12;1 Plan of the talk · Background and history · Algorithms and Implementation · Summary of the talk · Background and history · Algorithms and Implementation · Summary of data and highlights

Cremona, John

349

The Orbital Light Curve of Aquila X-1  

E-Print Network [OSTI]

We obtained R- and I-band CCD photometry of the soft X-ray transient/neutron- star binary Aql X-1 in 1998 June while it was at quiescence. We find that its light curve is dominated by ellipsoidal variations, although the ellipsoidal variations are severely distorted and have unequal maxima. After we correct for the contaminating flux from a field star located only 0.46" away, the peak-to-peak amplitude of the modulation is ~0.25 mag in the R band, which requires the orbital inclination to be greater than 36 degrees. The orbital period we measure is consistent with the 18.95 h period measured by Chevalier & Ilovaisky (1998). During its outbursts the light curve of Aql X-1 becomes single humped. The outburst light curve observed by Garcia et al. (1999) agrees in phase with our quiescent light curve. We show that the single humped variation is caused by a ``reflection effect,'' that is, by heating of the side of the secondary star facing towards the neutron star.

William F. Welsh; Edward L. Robinson; Patrick Young

2000-04-25T23:59:59.000Z

350

The dynamics of mercury flow in a curved pipe  

E-Print Network [OSTI]

The dynamics of mercury flow in a curved pipe Yan Zhan Foluso LadeindeFoluso Ladeinde 11 of the problem Pi t ff t· Pipe curvature effect · Laminar flow in the mercury supply pipe l i· Conclusion #12 Project. · Target delivery systems involves pipe curvature, axially- d d t di l di t d l l th tdependent

McDonald, Kirk

351

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.

352

On the Use of Weber Polynomials in Elliptic Curve Cryptography  

E-Print Network [OSTI]

On the Use of Weber Polynomials in Elliptic Curve Cryptography Elisavet Konstantinou1,2 , Yannis C using the Complex Multiplication method which typically uses the roots of Hilbert or Weber polynomials and unifying manner a complete set of transformations of the roots of a Weber polynomial to the roots of its

Zaroliagis, Christos D.

353

A Construction for Computer Visualization Certain Complex Curves  

E-Print Network [OSTI]

A Construction for Computer Visualization of Certain Complex Curves Andrew J. Hanson Computer representation of a manifold's geometry. Driven by this motivation, we found an extremely use- ful construction variables. Our construction is ideally suited for interactive computer graphics systems; in addition

Indiana University

354

Efficient Techniques for High-Speed Elliptic Curve Cryptography  

E-Print Network [OSTI]

Gebotys Department of Electrical and Computer Engineering, University of Waterloo, Canada, {plonga] is an integer, is the central and most time-consuming operation in Elliptic Curve Cryptography (ECC). Hence, its gained increasing importance in recent years. In this work, we combine several efficient techniques

355

Status for Learning Curves indlg ved BES temadag om  

E-Print Network [OSTI]

;Characteristics of technical changes in wind power technology · Up-scaling of turbines · Improved efficiency's Law": Size - in rated power - doubles every four years #12;On Experience Curves · Cost decreases assessment, forecasting, scenarios, the development of energy models, etc. Researchers will use values

356

Efficient Algorithms for Implementing Elliptic Curve PublicKey Schemes  

E-Print Network [OSTI]

Efficient Algorithms for Implementing Elliptic Curve Public­Key Schemes by Dan Beauregard A Thesis Cyganski Thesis Advisor Thesis Committee Dr. Stanley Selkow Dr. John Orr Thesis Committee Department Head #12; Preface This thesis describes the research which I conducted while completing my graduate work

357

Progress Letter Report on Bending Fatigue Test System Development for Spent Nuclear Fuel Vibration Integrity Study (Out-of-cell fatigue testing development - Task 2.4)  

SciTech Connect (OSTI)

Vibration integrity of high burn-up spent nuclear fuel in transportation remains to be a critical component of US nuclear waste management system. The structural evaluation of package for spent fuel transportation eventually will need to see if the content or spent fuel is in a subcritical condition. However, a system for testing and characterizing such spent fuel is still lacking mainly due to the complication involved with dealing radioactive specimens in a hot cell environment. Apparently, the current state-of-the-art in spent fuel research and development is quite far away from the delivery of reliable mechanical property data for the assessment of spent fuels in the transport package evaluation. Under the sponsorship of US NRC, ORNL has taken the challenge in developing a robust testing system for spent fuel in hot cell. An extensive literature survey was carried out and unique requirements of such testing system were identified. The U-frame setup has come to the top among various designs examined for reverse bending fatigue test of spent fuel rod. The U-frame has many features that deserve mentioned here: Easy to install spent fuel rod in test; Less linkages than in conventional bending test setup such as three-point or four-point bending; Target the failure mode relevant to the fracture of spent fuel rod in transportation by focusing on pure bending; The continuous calibrations and modifications resulted in the third generation (3G) U-frame testing setup. Rigid arms are split along the LBB axis at rod sample ends. For each arm, this results in a large arm body and an end piece. Mating halves of bushings were modified into two V-shaped surfaces on which linear roller bearings (LRB) are embedded. The rod specimen is installed into the test fixture through opening and closing slide end-pieces. The 3G apparently has addressed major issues of setup identified in the previous stage and been proven to be eligible to be further pursued in this project. On the other hand, the purchase of universal testing machine or Bose dual LM2 TB was completed and the testing system was delivered to ORNL in August 2012. The preliminary confirmation of the system and on-site training were given by Bose field engineer and regional manager on 8/1-8/2/2012. The calibration of Bose testing system has been performed by ORNL because the integration of ORNL setup into the Bose TestBench occurred after the installation. Major challenge with this process arose from two aspects: 1) the load control involves two load cells, and 2) U-frame setup itself is a non-standard specimen. ORNL has been able to implement the load control through Cycle Indirect along with pinning the U-frame setup. Two meetings with ORNL hot-cell group (November 2012 and January 2013) were held to discuss the potential issues with both epoxy mounting of rigid sleeve and U-frame setup. Many suggestions were provided to make the procedure friendlier to the manipulator in hot cell. Addressing of these suggestions resulted in another cycle of modifications of both vise mold and setup. The initial meeting with ORNL I&C group occurred in November 2012 with regard to the Bose cable modification and design of central panel to integrate the cables and wires. The first round of cable modification and central panel fabrication was completed in February 2012. The testing with the modified cables exhibited substantial noises and the testing system was not shown to be stable. It was believed the cross talk was responsible to the noise, and a central panel with a better grounding and shielding was highly recommended. The central panel has been re-designed and fabricated in March 2013. In the subsequent period, the ORNL made substantial effort to debug the noises with the load cell channel, and to resolve the noises and nonlinearity with RDP LVDTs related to the integration of RDP LVDTs to Bose system. At the same time, ORNL has completed the verification tests of Bose test system, including cycle tests under reversal bending in load control, bending tests under monotonic load, and cycle test

Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Cox, Thomas S [ORNL; Baldwin, Charles A [ORNL; Bevard, Bruce Balkcom [ORNL

2013-08-01T23:59:59.000Z

358

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

359

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

360

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

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

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

362

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

363

Surface Studies of Ultra Strength Drilling Steel after Corrosion Fatigue in Simulated Sour Environment  

SciTech Connect (OSTI)

The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (< 5000 m) is about to be reached, thereby pushing the oil and natural gas industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the notch in the solution at 20 C. Accumulation of the corrosion products is visible along the crack. The EDX chemical analysis near the crack tip found iron, sulfur and oxygen in the passive layer. The surface of the sample after the fatigue test in the sour environment at 85{sup o}, Fig. 2, C looks different from that fatigued surface at 20 C. The crack propagates across the passive film that covers the surface fairly uniformly. Some spallation of the passive film is observed near the notch. The EDX chemical analysis of the passive film near the crack tip identified mainly iron, carbon and oxygen. It appears that temperature plays a very important role in formation of the passive film. This may be associated with different solubility of H{sub 2}S in the solution, which will be further studied.

M. Ziomek-Moroz; J.A. Hawk; R. Thodla; F. Gui

2012-05-06T23:59:59.000Z

364

Extremum seeking control techniques applied to photovoltaic systems with multimodal power curves  

E-Print Network [OSTI]

) Current(A) 0 200 320025 I-V curve P-V curve VMPP Power(W) 1000 Fig. 1. Photovoltaic cell I-V and P nonlinear steady-state characteristics, expressed as either current versus voltage (the so called I-V curve), or as power versus voltage (the P-V curve, like the one in Fig. 1). The I-V and P-V curves of a PV system vary

Boyer, Edmond

365

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

366

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

367

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

368

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

369

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

370

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

371

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

372

On calculation of microlensing light curve by gravitational lens caustic  

E-Print Network [OSTI]

For an analysis of microlensing observational data in case of binary gravitational lenses as well as for an interpretation of observations of high magnification events in multiple images of a lensed quasar it is necessary to calculate for a given source the microlensing light curve by a fold caustic. This problem comes to the numerical calculation of a singular integral. We formulated the sufficient condition of a convergence of the integral sum for this singular integral. The strictly approach to the problem of a comparison of model results with the unequally sampled observational data consists in calculation of the model light curve in equidistant points of the canonical dissection of the integration segment and a following interpolation of its values at the moments of observations.

M. B. Bogdanov

2001-02-02T23:59:59.000Z

373

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

374

Generation of Closed Timelike Curves with Rotating Superconductors  

E-Print Network [OSTI]

The spacetime metric around a rotating SuperConductive Ring (SCR) is deduced from the gravitomagnetic London moment in rotating superconductors. It is shown that theoretically it is possible to generate Closed Timelike Curves (CTC) with rotating SCRs. The possibility to use these CTC's to travel in time as initially idealized by G\\"{o}del is investigated. It is shown however, that from a technology and experimental point of view these ideas are impossible to implement in the present context.

Clovis Jacinto de Matos

2007-01-19T23:59:59.000Z

375

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

376

Discussions on the Cancellation Effect on a Curved Orbit  

SciTech Connect (OSTI)

The canonical formulation and the cancellation effect for bunch dynamics under collective interaction on a curved orbit were presented in Ref. [*]. Some possible controversial representations of the cancellation effect were later addressed by Geloni et al.** In this study, we discuss all the points raised in Ref. [**] based on our canonical treatment, and show how these points can be perceived from the view point of the cancellation picture.

Rui Li; Ya. S. Derbenev

2005-05-16T23:59:59.000Z

377

Analysis of gas deliverability curves for predicting future well performance  

E-Print Network [OSTI]

is how to use backpressure test data to determine reservoir characteristics and predict fu tu re reservoir p er f orma nc e. The commonly used deliverability equation does not adequately consider the effects of real gas behavior or non-Darcy flow.... These factors cause the gas deliverability curves to deviate from the expected straight line and to shi ft position with time. To investigate these problems, a pseudosteady-state flow model was used to simulate backpressure tests for known reservoirs...

Corbett, Thomas Gary

1985-01-01T23:59:59.000Z

378

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

379

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

380

Theory of a quantum noncanonical field in curved spacetimes  

SciTech Connect (OSTI)

Much attention has been recently devoted to the possibility that quantum gravity effects could lead to departures from special relativity in the form of a deformed Poincare algebra. These proposals go generically under the name of doubly or deformed special relativity (DSR). In this article we further explore a recently proposed class of quantum field theories, involving noncanonically commuting complex scalar fields, which have been shown to entail a DSR-like symmetry. An open issue for such theories is whether the DSR-like symmetry has to be taken as a physically relevant symmetry, or if in fact the 'true' symmetries of the theory are just rotations and translations while boost invariance has to be considered broken. Here we analyze this issue by extending the known results to curved spacetime under both of the previous assumptions. We show that if the symmetry of the free theory is taken to be a DSR-like realization of the Poincare symmetry, then it is not possible to render such a symmetry a gauge symmetry of the curved physical spacetime. However, it is possible to introduce an auxiliary spacetime which allows one to describe the theory as a standard quantum field theory in curved spacetime. Alternatively, taking the point of view that the noncanonical commutation of the fields actually implies a breakdown of boost invariance, the physical spacetime manifold has to be foliated in surfaces of simultaneity, and the field theory can be coupled to gravity by making use of the Arnowitt-Deser-Misner prescription.

Indurain, Javier; Liberati, Stefano [Departamento de Fisica Teorica, Universidad de Zaragoza, Zaragoza 50009 (Spain); SISSA, Via Beirut 2-4, 34151 Trieste (Italy) and INFN sezione di Trieste (Italy)

2009-08-15T23:59:59.000Z

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.


381

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

382

Design and optimization of polymer electrolyte membrane (PEM) fuel cells  

E-Print Network [OSTI]

Design and optimization of polymer electrolyte membrane (PEM) fuel cells M. Grujicic* , K optimization algorithm to determine an optimum design of the fuel cell with respect to the operation difference has the largest effect on the predicted polarization curve of the fuel cell. However, the optimal

Grujicic, Mica

383

Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing  

SciTech Connect (OSTI)

An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (LiEtsionTalke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

Ling, Xue; Wang, Yusheng [Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084 (China); Li, Xide, E-mail: lixide@tsinghua.edu.cn [Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084 (China); Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084 (China)

2014-10-15T23:59:59.000Z

384

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

385

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

386

Fatigue analysis of single-span and two-span solid-sawn, creosote-treated southern pine railroad bridge stringers  

E-Print Network [OSTI]

be the preferred method of construction and rehabilitation of timber bridges. To properly assess the fatigue resistance of timber bridge stringers, it was necessary to conduct full-scale fatigue tests on stringer specimens. As part of the Timber Bridge Life...

Comardo, Angelique France

2000-01-01T23:59:59.000Z

387

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

388

Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment  

SciTech Connect (OSTI)

Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.

Wire, G. L.; Mills, W. J.

2002-08-01T23:59:59.000Z

389

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

390

192 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 1, JANUARY 2013 Monitoring Wind Farms With Performance Curves  

E-Print Network [OSTI]

to varying loads, which in turn lead to wind turbine faults, e.g., spalled bearings and fractured gears--Three different operational curves--the power curve, rotor curve, and blade pitch curve--are presented the reference curves of wind power, rotor speed, and blade pitch angle, with wind speed as an input variable

Kusiak, Andrew

391

DETERMINISTIC COMPONENTS IN THE LIGHT CURVE AMPLITUDE OF Y OPH  

SciTech Connect (OSTI)

About two decades after the discovery of the amplitude decline of the light curve of the classical Cepheid Y Oph, its study is resumed using an increased amount of homogenized data and an extended time base. In our approach, the investigation of different time series concerning the light curve amplitude of Y Oph is not only the reason for the present study, but also a stimulus for developing a coherent methodology for studying long- and short-term variability phenomena in variable stars, taking into account the details of concrete observing conditions: amount of data, data sampling, time base, and individual errors of observational data. The statistical significance of this decreasing trend was estimated by assuming its linearity. We approached the decision-making process by formulating adequate null and alternative hypotheses, and testing the value of the regression line slope for different data sets via Monte Carlo simulations. A variability analysis, through various methods, of the original data and of the residuals obtained after removing the linear trend was performed. We also proposed a new statistical test, based on amplitude spectrum analysis and Monte Carlo simulations, intended to evaluate how detectible is a given (linear) trend in well-defined observing conditions: the trend detection probability. The main conclusion of our study on Y Oph is that, even if the false alarm probability is low enough to consider the decreasing trend to be statistically significant, the available data do not allow us to obtain a reasonably powerful test. We are able to confirm the light curve amplitude decline, and the order of magnitude of its slope with a better statistical substantiation. According to the obtained values of the trend detection probability, it seems that the trend we are dealing with is marked by a low detectibility. Our attempt to find signs of possible variability phenomena at shorter timescales ended by emphasizing the relative constancy of our data, within their precision limits.

Pop, Alexandru; Turcu, Vlad [Astronomical Institute of the Romanian Academy, Astronomical Observatory Cluj-Napoca, Str. Ciresilor 19, 400487 Cluj-Napoca (Romania); Vamos, Calin ['T. Popoviciu' Institute of Numerical Analysis, Romanian Academy, P.O. Box 68, 400110 Cluj-Napoca (Romania)], E-mail: andi_pop@yahoo.com, E-mail: vladturcu@yahoo.com, E-mail: cvamos@ictp.acad.ro

2010-02-15T23:59:59.000Z

392

Average Soil Water Retention Curves Measured by Neutron Radiography  

SciTech Connect (OSTI)

Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.

Cheng, Chu-Lin [ORNL; Perfect, Edmund [University of Tennessee, Knoxville (UTK); Kang, Misun [ORNL; Voisin, Sophie [ORNL; Bilheux, Hassina Z [ORNL; Horita, Juske [Texas Tech University (TTU); Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2011-01-01T23:59:59.000Z

393

Cancer cachexia decreases specific force and accelerates fatigue in limb muscle  

SciTech Connect (OSTI)

Highlights: C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. C-26 cancer cachexia causes a significant decrease in limb muscle specific force. C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative soleus is also important for normal locomotion, we further performed a fatigue trial in the soleus and found that the decrease in relative force was greater and more rapid in solei from C-26 mice compared to controls. These data demonstrate that severe cancer cachexia causes profound muscle weakness that is not entirely explained by the muscle atrophy. In addition, cancer cachexia decreases the fatigue resistance of the soleus muscle, a postural muscle typically resistant to fatigue. Thus, specifically targeting contractile dysfunction represents an additional means to counter muscle weakness in cancer cachexia, in addition to targeting the prevention of muscle atrophy.

Roberts, B.M. [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)] [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States); Frye, G.S.; Ahn, B.; Ferreira, L.F. [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States)] [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States); Judge, A.R., E-mail: arjudge@phhp.ufl.edu [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)

2013-06-07T23:59:59.000Z

394

Historical overview on Vacuum suitable Welding and fatigue resistance in Research Devices  

E-Print Network [OSTI]

New inventions change the approach of vacuum suitable welding for research purpose. With orbital welding, laser welding and robot welding the possibilities increase to fabricate larger vessels more accurately. Despite this development there is still no perfect understanding on how to avoid virtual leaks and how to make such joints suitable for dynamic stress. By recalling its historical development, it is apparent how welding mistakes began occurring systematically and how to avoid them. With ASDEX-Upgrade as an example, it is shown how the attempt to conduct vacuum suitable welding has decreased the fatigue strength. ITER could repeat the mistakes of ASDEX-Upgrade even for unwanted welding (accidental fusing of joints).

Wolf, Martin

2015-01-01T23:59:59.000Z

395

Crack closure effects on fatigue crack growth thresholds and remaining life in an HSLA steel  

SciTech Connect (OSTI)

The effects of crack closure on the near-threshold corrosion fatigue crack growth behavior of Mil S-24645 HSLA steel and its weld metal have been investigated in air, ASTM seawater at the free corrosion potential, and ASTM seawater at {minus}0.8V and {minus}1.0V (SCE) using frequencies of 10, 2, and 0.2 Hz, and a stress ratio, R = 0.1. Remaining life, in the presence and absence of crack closure, has been estimated as a function of applied stress range for a structure containing a 3-mm-deep surface semi-elliptical flaw.

Todd, J.A.; Mostovoy, S. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Mechanical, Materials and Aerospace Engineering; Chen, L. [Texas Instruments, Attleboro, MA (United States); Yankov, E.Y. [A. Finkl and Sons, Chicago, IL (United States)

1997-02-01T23:59:59.000Z

396

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

397

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

398

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

E-Print Network [OSTI]

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

Pei, Jian

399

Spacefilling curves for 2simplicial meshes created with bisections and reflections  

E-Print Network [OSTI]

computational 2meshes which can be very e#ciently loadbalanced with the use of a spacefilling curve. Keywords: Grid generation, space filling curve, load balancing Mathematics Subject Classification 2000: 65M the elements in curvetraversal order, and the required loadbalance redistribution amounts to a possible

Eindhoven, Technische Universiteit

400

IEEE TRANSACTIONS ON POWER SYSTEMS, CHEN, DENG AND HUO. 1 Electricity Price Curve Modeling by Manifold  

E-Print Network [OSTI]

markets. Index Terms-- Electricity spot price, locational marginal price, electricity forward curveIEEE TRANSACTIONS ON POWER SYSTEMS, CHEN, DENG AND HUO. 1 Electricity Price Curve Modeling and prediction of electricity price curves by applying the manifold learning methodology. Cluster analysis based

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

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 23, NO. 3, AUGUST 2008 877 Electricity Price Curve Modeling  

E-Print Network [OSTI]

--Electricity forward curve, electricity spot price, forecasting, locational marginal price, manifold learning. IIEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 23, NO. 3, AUGUST 2008 877 Electricity Price Curve approach for the modeling and analysis of electricity price curves by ap- plying the manifold learning

Huo, Xiaoming

402

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

403

Indexing Moving Objects by Space Filling Curves in the Dual Space  

E-Print Network [OSTI]

The Bdual ­ tree: Indexing Moving Objects by Space Filling Curves in the Dual Space By Man Lung Yiu Objects by Space Filling Curves in the Dual Space Introduction Related work Problem definition: Indexing Moving Objects by Space Filling Curves in the Dual Space Introduction Related work Problem

Kaiserslautern, Universität

404

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

405

HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves HTP over Algebraic Extensions of Q  

E-Print Network [OSTI]

HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves HTP over Algebraic Extensions and Computability, ICMS, June 2007 #12;HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves A Talk in Two Rounds Round I: Normforms Today Round II: Elliptic Curves Later #12;HTP over Algebraic Extensions

Shlapentokh, Alexandra

406

HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves HTP over Algebraic Extensions of Q  

E-Print Network [OSTI]

HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves HTP over Algebraic Extensions and Computability, ICMS, June 2007 #12;HTP over Algebraic Extensions of Q: Normforms vs. Elliptic Curves A Talk in Two Rounds Round II: Elliptic Curves Today #12;HTP over Algebraic Extensions of Q: Normforms vs

Shlapentokh, Alexandra

407

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

408

CSC6870 Computer Graphics II B-Spline Curves and NURBS  

E-Print Network [OSTI]

CSC6870 Computer Graphics II B-Spline Curves and NURBS CSC6870 Computer Graphics II Motivation continuity CSC6870 Computer Graphics II B-spline Curve CSC6870 Computer Graphics II B-Splines · Curve CSC6870 Computer Graphics II B-Splines Basis Functions: Cox- deBoor recursion · The basis function

Hua, Jing

409

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

410

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

411

Estimating type curve parameters with the cumulative curvature method  

E-Print Network [OSTI]

situations remain: the well test data span may be inadequate for the replots, and the required programming of the statistical techniques causes problems for the well test. analyst. 10 10 s =20 5 = 10 s 5 s=0 s=-5 c, ~ 7 10 10 10 4 10 10 10 Pig. 1... ~0 Oq 10 10 10 tp/CO 10 Fig. 2 ? Gringatten type - utsres Cn 100 gs C e" V CI CI A O. 10 1030 10 io ~~&~~& ~ 0 . . 3 0. 1 0. 1 10 I; 100 'D Fig. 3 ? Bcnrdet press&. . re derivstive type curves 1000 10000 Inade uate Data...

Harris, Dan Edward

1986-01-01T23:59:59.000Z

412

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

413

High temperature fracture and fatigue of ceramics. Annual technical progress report No. 6, August 15, 1994--August 14, 1995  

SciTech Connect (OSTI)

This report covers work done in the first year of our new contract {open_quotes}High Temperature Fracture and Fatigue of Ceramics,{close_quotes} which commenced in August, 1995 as a follow-on from our prior contract {open_quotes}Mechanisms of Mechanical Fatigue in Ceramics.{close_quotes} Our activities have consisted mainly of studies of the failure of fibrous ceramic matrix composites (CMCs) at high temperature; with a little fundamental work on the role of stress redistribution in the statistics of fracture and cracking in the presence of viscous fluids.

Cox, B.

1996-04-01T23:59:59.000Z

414

New Reliability Assessment Method for Solder Joints in BGA Package by Considering the Interaction between Design Factors  

E-Print Network [OSTI]

As the integration and the miniaturization of electronics devices, design space become narrower and interactions between design factors affect their reliability. This paper presents a methodology of quantifying the interaction of each design factor in electronics devices. Thermal fatigue reliability of BGA assembly was assessed with the consideration of the interaction between design factors. Sensitivity analysis shows the influence of each design factor to inelastic strain range of a solder joint characterizing the thermal fatigue life if no interaction occurs. However, there is the interaction in BGA assembly since inelastic strain range depends on not only a mismatch in CTE but also a warpage of components. Clustering can help engineers to clarify the relation between design factors. The variation in the influence was taken to quantify the interaction of each design factor. Based on the interaction, simple evaluating approach of inelastic strain range for the BGA assembly was also developed. BGA package was simplified into a homogeneous component and equivalent CTE wascalculated from the warpage of BGA and PCB. The estimated equation was derived by using the response surface method as a function of design factors. Based upon these analytical results, design engineers can rate each factor's effect on reliability and assess the reliability of their basic design plan at the concept design stage.

Satoshi Kondo; Qiang Yu; T. Shibutani; M. Shiratori

2008-01-07T23:59:59.000Z

415

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

416

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

417

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

418

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

419

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

420

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

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

Enhanced fatigue and aging resistance using reactive powders in the optical fiber buffer coating V. V. Rondinella  

E-Print Network [OSTI]

of small quantities of colloidal silica to the UV- curable polymer coating of fused silica optical fiber for the surface roughening that causes the fatigue knee and strength degradation during zero-stress aging roughness and strength degradation during zero-stress aging in harsh conditions has now been well estab1

Matthewson, M. John

422

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

423

Static and Fatigue Analysis of Wind Turbine Blades Subject to Cold Weather Conditions Using Finite Element Analysis  

E-Print Network [OSTI]

Static and Fatigue Analysis of Wind Turbine Blades Subject to Cold Weather Conditions Using Finite Turbine Blades Subject to Cold Weather Conditions Using Finite Element Analysis by Patricio Andres Lillo experienced in candi- date Canadian wind turbine deployment locations. The thesis then narrows its focus

Victoria, University of

424

Methodology for predicting torsional fatigue life of turbine generator shafts using crack initiation plus propagation. Final report  

SciTech Connect (OSTI)

An overall methodology now exists that addresses both crack initiation and propagation in predicting the fatigue life of large turbine generator shafts. It can estimate previous torsional transient damage and predict residual life. In short, this improved methodology allows utilities to determine the availability of turbogenerators with greater confidence.

Anderson, A.F.; Williams, R.A.; Wilkening, W.W.; LeFort, P.N.

1985-11-01T23:59:59.000Z

425

FATIGUE RESISTANT FIBERGLASS LAMINATES FOR WIND TURBINE BLADES (published for Wind Energy 1996, ASME, pp. 46-51)  

E-Print Network [OSTI]

FATIGUE RESISTANT FIBERGLASS LAMINATES FOR WIND TURBINE BLADES (published for Wind Energy 1996/MSU database to lifetime prediction as described in Ref. [1]. INTRODUCTION Most U.S. fiberglass wind turbine of unidirectional (0E) and 45 stranded fabric layers, typical blade materials, vary significantly in tensile

426

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

427

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.

428

Graphene: QFT in curved spacetimes close to experiments  

E-Print Network [OSTI]

A recently proposed step-by-step procedure, to merge the low-energy physics of the $\\pi$-bonds electrons of graphene, and quantum field theory on curved spacetimes, is recalled. The last step there is the proposal of an experiment to test a Hawking-Unruh effect, emerging from the model, that manifests itself as an exact (within the model) prediction for the electronic local density of states, in the ideal case of the graphene membrane shaped as a Beltrami pseudosphere. A discussion about one particular attempt to experimentally test the model on molecular graphene is presented, and it is taken as an excuse to solve some basic issues that will help future experiments. In particular, it is stated that the effect should be visible on generic surfaces of constant negative Gaussian curvature, that are infinite in number.

Alfredo Iorio

2013-04-09T23:59:59.000Z

429

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

430

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

431

Hidden symmetries and killing tensors on curved spaces  

SciTech Connect (OSTI)

Higher-order symmetries corresponding to Killing tensors are investigated. The intimate relation between Killing-Yano tensors and nonstandard supersymmetries is pointed out. In the Dirac theory on curved spaces, Killing-Yano tensors generate Dirac-type operators involved in interesting algebraic structures as dynamical algebras or even infinite dimensional algebras or superalgebras. The general results are applied to space-times which appear in modern studies. One presents the infinite dimensional superalgebra of Dirac type operators on the 4-dimensional Euclidean Taub-NUT space that can be seen as a twisted loop algebra. The existence of the conformal Killing-Yano tensors is investigated for some spaces with mixed 3-Sasakian structures.

Ianus, S. [University of Bucharest, Department of Mathematics (Romania); Visinescu, M., E-mail: mvisin@theory.nipne.r [Institute for Physics and Nuclear Engineering, Department of Theoretical Physics (Romania); Vilcu, G. E. [Petroleum-Gas University of Ploiesti, Department of Mathematics and Computer Science (Romania)

2010-11-15T23:59:59.000Z

432

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

433

Gamma prime embrittlement and thermal fatigue cracking of a hydrogen reformer burner end  

SciTech Connect (OSTI)

An investigation into the premature failure of an Alloy 800HT (UNS N08811) oxygen-gas mixer water jacketed end is discussed. Detailed metallurgical analyses showed that gamma prime [Ni{sub 3} (Al, Ti)] embrittlement and thermal fatigue cracking led to eventual leakage. The reduced lif e of the Alloy 800HT (UNS N08811) replacement (problems after only a year) was traced to its higher Al + Ti content (1.1%) compared to Alloy 800H (0.6% Al + Ti) which lasted over two years. While higher aluminum and titanium levels improve high temperature creep and stress rupture properties, both are sigma formers and, at levels > 0.6%, tend to form gamma prime with nickel. The choice of alternative metallurgies requires careful considerations of physical, mechanical and thermal properties as well as an understanding of complex stresses and stress distributions.

Dias, O.C.; Mack, N.C. [Amoco Oil Co., Texas City, TX (United States)

1994-12-31T23:59:59.000Z

434

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

435

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

436

Timescale stretch parameterization of Type Ia supernova B-band light curves  

E-Print Network [OSTI]

the light curve of Type Ia supernovae discovered by theof the high-redshift supernovae. This work was supported inobjects. Subject headings: supernovae: general cosmology:

2001-01-01T23:59:59.000Z

437

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

438

An Econometric Model of the Yield Curve With Macroeconomic Jump Effects  

E-Print Network [OSTI]

Kenneth Singleton (1997). An Econometric Model of the TermDiscretely-Sampled Data. Econometric Theory 4, pp. 231-An Econometric Model of the Yield Curve with Macroeconomic

Piazzesi, Monika

2001-01-01T23:59:59.000Z

439

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...

440

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

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

Use of experience curves to estimate the future cost of power plants with CO2 capture  

E-Print Network [OSTI]

2004. Experience curves for power plant emission controlassessments of fossil fuel power plants with CO 2 capturethe future cost of power plants with CO 2 capture Edward S.

Rubin, Edward S.; Yeh, Sonia; Antes, Matt; Berkenpas, Michael; Davison, John

2007-01-01T23:59:59.000Z

442

Multi-phase decline curve analysis with normalized rate and time  

E-Print Network [OSTI]

Material Balance Equation. The purpose of the current work is to develop a normalized time and a normalized rate which can be applied to the Fetkovich type curve or any other decline type curve. From a Fetkovich type curve analysis, an engineer can...MULTI-PHASE DECLINE CURVE ANALYSIS WITH NORMALIZED RATE AND TIME A Thesis by MICHAEL LEE FRAIM Submitted to the Graduate College of Texas ARM University &n partial fulf 111ment of the requirements for the degree of MASTER OF SCIENCE August...

Fraim, Michael Lee

1988-01-01T23:59:59.000Z

443

Use of experience curves to estimate the future cost of power plants with CO2 capture  

E-Print Network [OSTI]

the combined cycle gas turbinean experience curve analysis.reduction (SCR) systems, gas turbine combined cycle (GTCC)catalytic reduction (SCR) Gas turbine combined cycle (GTCC)

Rubin, Edward S.; Yeh, Sonia; Antes, Matt; Berkenpas, Michael; Davison, John

2007-01-01T23:59:59.000Z

444

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

445

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

446

New Curved Spacetime Dirac Equations - On the Anomalous Gyromagnetic Ratio  

E-Print Network [OSTI]

I propose three new curved spacetime versions of the Dirac Equation. These equations have been developed mainly to try and account in a natural way for the observed anomalous gyromagnetic ratio of Fermions. The derived equations suggest that particles including the Electron which is thought to be a point particle do have a finite spatial size which is the reason for the observed anomalous gyromagnetic ratio. A serendipitous result of the theory, is that, two of the equation exhibits an asymmetry in their positive and negative energy solutions the first suggestion of which is clear that a solution to the problem as to why the Electron and Muon - despite their acute similarities - exhibit an asymmetry in their mass is possible. The Mourn is often thought as an Electron in a higher energy state. Another of the consequences of three equations emanating from the asymmetric serendipity of the energy solutions of two of these equations, is that, an explanation as to why Leptons exhibit a three stage mass hierarchy is possible.

G. G. Nyambuya

2008-09-06T23:59:59.000Z

447

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

448

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

449

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

450

A Table of Areas Under Disease Progress Curves.  

E-Print Network [OSTI]

Chillicothe-Vernon, TX 76384; and Professor Department of Plant Pathology University of Minnesota St. Paul, MN 55108 A T a b l e o f A r e a s Under D i s e a s e P r o g r e s s Curves 3 Denn i s A. J o h n s o n and Roy D . \\ W i l c o x s o... s e a s e . With a p p r o p r i a t e l y p l a n n e d e x p e l ; d i s e a s e p r o g r e s s c u r v e s may b e u sed t o compare t h e e f f e c t s o f cul,,,,,,, r a c e s o f t h e p a t h o g e n s , o r i n d i v i d u...

Johnson, Dennis A.; Wilcoxson, Roy D.

1980-01-01T23:59:59.000Z

451

Curious Variables Experiment (CURVE). Three Periodicities of BF Ara  

E-Print Network [OSTI]

We report CCD photometry of the dwarf nova BF Ara throughout fifteen consecutive nights in quiescence. Light curve in this interval is dominated by a large amplitude around 0.8 mag modulation consisting two periods. Higher amplitude signal is characterized by period of 0.082159(4) days, which was increasing at the rate of dotP/Psh = 3.8(3)* 10^{-5}. Weaker and stable signal has period of 0.084176(21) days. Knowing the superhump period of BF Ara determined by Kato et al. (2003) and equal to 0.08797(1) days, the first modulation is interpreted as quiescent negative superhump arising from retrograde precesion of titled accretion disk and the latter one as an orbital period of the binary. The respective period excess and defect are epsilon_+ = 4.51% +/- 0.03% and epsilon_- = -2.44% +/- 0.02%. Thus BF Ara is yet another in-the-gap nova with mass ratio q of around 0.21.

A. Olech; A. Rutkowski; A. Schwarzenberg-Czerny

2008-01-10T23:59:59.000Z

452

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

453

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

E-Print Network [OSTI]

are determined based on the backbone curve, and 2P the maximum suction. ? and ? are dimensionless parameters and equal to 0.433 and 0.203, respectively (Jiao, 2007). The value of ? indicates that the maximum suction is about 20% of the maximum resistance...

Nakhaee, Ali

2011-02-22T23:59:59.000Z

454

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

455

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

456

AISI/DOE Technology Roadmap Program: Characterization of Fatigue and Crash Performance of New Generation High Strength Steels for Automotive Applications  

SciTech Connect (OSTI)

A 2-year project (2001-2002) to generate fatigue and high strain data for a new generation of high strength steels (HSS) has been completed in December 2002. The project tested eleven steel grades, including Dual Phase (DP) steels, Transformation-Induced Plasticity (TRIP) steels, Bake Hardenable (BH) steels, and conventional High Strength Low Alloy (HSLA) steels. All of these steels are of great interest in automotive industry due to the potential benefit in weight reduction, improved fuel economy, enhanced crash energy management and total system cost savings. Fatigue behavior includes strain controlled fatigue data notch sensitivity for high strength steels. High strain rate behavior includes stress-strain data for strain rates from 0.001/s to 1000/s, which are considered the important strain rate ranges for crash event. The steels were tested in two phases, seven were tested in Phase 1 and the remaining steels were tested in Phase. In a addition to the fatigue data and high st rain rate data generated for the steels studied in the project, analyses of the testing results revealed that Advanced High Strength Steels (AHSS) exhibit significantly higher fatigue strength and crash energy absorption capability than conventional HSS. TRIP steels exhibit exceptionally better fatigue strength than steels of similar tensile strength but different microstructure, for conditions both with or without notches present

Brenda Yan; Dennis Urban

2003-04-21T23:59:59.000Z

457

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

458

Quantum Inequality Restrictions on Negative Energy Densities in Curved Spacetimes  

E-Print Network [OSTI]

In quantum field theory, there exist states in which the expectation value of the energy density for a quantized field is negative. These negative energy densities lead to many problems. Although quantum field theory introduces negative energies, it also provides constraints in the form of quantum inequalities (QI's). These uncertainty principle-type relations limit the magnitude and duration of any negative energy. We derive a general form of the QI on the energy density for both the quantized scalar and electromagnetic fields in static curved spacetimes. In the case of the scalar field, the QI can be written as the Euclidean wave operator acting on the Euclidean Green's function. Additionally, a small distance expansion on the Green's function is used to derive the QI in the short sampling time limit. It is found that the QI in this limit reduces to the flat space form with subdominant correction terms which depend on the spacetime geometry. Several example spacetimes are studied in which exact forms of the QI's can be found. These include the three- and four-dimensional static Robertson-Walker spacetimes, flat space with perfectly reflecting mirrors, Rindler and static de Sitter space, and the spacetime outside a black hole. Finally, the application of the quantum inequalities to the Alcubierre warp drive spacetime leads to strict constraints on the thickness of the negative energy region needed to maintain the warp drive. Under these constraints, we discover that the total negative energy required exceeds the total mass of the visible universe by a hundred billion times.

Michael John Pfenning; L. H. Ford

1998-05-11T23:59:59.000Z

459

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

460

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

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

i\\ccurate and Efficient Curve Detection in Images: The Importance Sarnpling Hough Transform *  

E-Print Network [OSTI]

i\\ccurate and Efficient Curve Detection in Images: The Importance Sarnpling Hough TransformCleIJltlty UlllHlV'C curves in an image. \\Ve also use probabilistic to develop stopping conditions for the algorithm. The is called the Importance Sam- Hough Transform (ISHT). We apply our method to both simulated

Washington at Seattle, University of

462

No-Go Theorem for Energy-Momentum Conservation in Curved Spacetime  

E-Print Network [OSTI]

It is pointed out that in curved spacetime, one cannot define the sum of energy-momemtum 4-vector over a space-like hypersurface. The difficulty in finding satisfactory gravitational energy-momentum complex stems from misunderstanding of this question. The law of conservation of energy-momentum holds valid only approximately when spacetime is not seriously curved.

Zhaoyan Wu

2007-02-10T23:59:59.000Z

463

Combining hydraulic knowledge and uncertain gaugings in the estimation of hydrometric rating curves: A Bayesian approach  

E-Print Network [OSTI]

Combining hydraulic knowledge and uncertain gaugings in the estimation of hydrometric rating curves HHLY, Hydrology-Hydraulics 5 rue de la Doua CS70077 69626 Villeurbanne cedex, France bCETE Ile analysis of rating curves arises from the quantitative as- sessment of (i) the hydraulic controls

Paris-Sud XI, Universit de

464

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

465

Special Polynomial Families for Generating More Suitable Elliptic Curves for Pairing-Based Cryptosystems  

E-Print Network [OSTI]

-Based Cryptosystems Pu Duan, Shi Cui and Choong Wah Chan School of Electrical and Electronic Engineering Nanyang in recent years. The best previous technique builds curves with = lg(q)/lg(r) 1 (k = 12) and = lg(q)/lg with arbitrary embedding degree k by certain special polynomial families. The new method generates curves with lg(q)/lg

466

Mercury Flow through a Long Curved Pipe Wenhai Li & Foluso Ladeinde  

E-Print Network [OSTI]

Mercury Flow through a Long Curved Pipe Wenhai Li & Foluso Ladeinde Department of Mechanical Engineering Stony Brook University Summary The flow of mercury in a long, curved pipe is simulated that includes the effects of the viscosity of mercury, turbulence in the pipe, pressure force, and pipe friction

McDonald, Kirk

467

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.

468

Long-Term Mitigation Strategies and Marginal Abatement Cost Curves: A Case Study on Brazil  

E-Print Network [OSTI]

Long-Term Mitigation Strategies and Marginal Abatement Cost Curves: A Case Study on Brazil Adrien abatement targets need to decide which abatement mea- sures to implement, and in which order. This paper investigates the ability of marginal abatement cost (MAC) curves to inform this decision, reanalyzing a MAC

Paris-Sud XI, Université de

469

Marginal abatement cost curves and the optimal timing of mitigation measures  

E-Print Network [OSTI]

Marginal abatement cost curves and the optimal timing of mitigation measures Adrien Vogt-Schilb 1, Washington D.C., USA Abstract Decision makers facing abatement targets need to decide which abatement mea- sures to implement, and in which order. Measure-explicit marginal abatement cost curves depict the cost

Paris-Sud XI, Université de

470

Generalising the GHS Attack on the Elliptic Curve Discrete Logarithm Problem  

E-Print Network [OSTI]

Generalising the GHS Attack on the Elliptic Curve Discrete Logarithm Problem F. Hess Technical succumb to the basic GHS attack, thereby weakening curves over F2155 further. We also discuss other possible extensions or variations of the GHS attack and conclude that they are not likely to yield further

Hess, Florian

471

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

472

The liquid-gas phase transition and the caloric curve of nuclear matter  

E-Print Network [OSTI]

in the critical phenomena [5-8], the caloric curve [9,10], the negative heat capacity [11,12] and the bimodalityThe liquid-gas phase transition and the caloric curve of nuclear matter K. Miyazaki E in the liquid-gas phase transition of nuclear matter. The recent great experimental progress [1-4] in nuclear

473

INFRARED LIGHT CURVES OF MIRA VARIABLE STARS FROM COBE DIRBE DATA Beverly J. Smith  

E-Print Network [OSTI]

INFRARED LIGHT CURVES OF MIRA VARIABLE STARS FROM COBE DIRBE DATA Beverly J. Smith Department have used the COBE DIRBE database to derive near- and mid-infrared light curves for a well-defined sample of 38 infrared-bright Mira variable stars and compared with optical data from the AAVSO

Luttermoser, Donald G.

474

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

475

Survival curves of heated bacterial spores:1 Effect of environmental factors on Weibull parameters2  

E-Print Network [OSTI]

be applied for canning process calculations.24 Key words:25 Weibull distribution, Heat treatment pH, recovery1 Survival curves of heated bacterial spores:1 Effect of environmental factors on Weibull heat13 resistance for non-log linear survival curves. One simple model derived from the Weibull14

Brest, Universit de

476

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

477

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

478

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

479

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

480

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

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

Constitutive Modeling of High Temperature Uniaxial Creep-Fatigue and Creep-Ratcheting Responses of Alloy 617  

SciTech Connect (OSTI)

Inconel Alloy 617 is a high temperature creep and corrosion resistant alloy and is a leading candidate for use in Intermediate Heat Exchangers (IHX) of the Next Generation Nuclear Plants (NGNP). The IHX of the NGNP is expected to experience operating temperatures in the range of 800 degrees - 950 degrees C, which is in the creep regime of Alloy 617. A broad set of uniaxial, low-cycle fatigue, fatigue-creep, ratcheting, and ratcheting-creep experiments are conducted in order to study the fatigue and ratcheting responses, and their interactions with the creep response at high temperatures. A unified constitutive model developed at North Carolina State University is used to simulate these experimental responses. The model is developed based on the Chaboche viscoplastic model framework. It includes cyclic hardening/softening, strain rate dependence, strain range dependence, static and dynamic recovery modeling features. For simulation of the alloy 617 responses, new techniques of model parameter determination are developed for optimized simulations. This paper compares the experimental responses and model simulations for demonstrating the strengths and shortcomings of the model.

P.G. Pritchard; L.J. Carroll; T. Hassan

2013-07-01T23:59:59.000Z

482

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

483

Design Quality Criteria Design Quality Criteria  

E-Print Network [OSTI]

Design Quality Criteria 19 Chapter 2 Design Quality Criteria This chapter discusses what qualities are desirable of an application protocol design, and what quality criteria can be used when evaluating or engineering an application protocol design. We recognize that design quality must be enabled by the design

van Sinderen, Marten

484

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

485

Design Considerations  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector General Office of Audit Services AuditTransatlantic Relations & the196-2011Waste viaDesign Code

486

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

487

SEISMIC RISK MAPS FOR EUROCODE-8 DESIGNED BUILDINGS Thomas Ulrich1  

E-Print Network [OSTI]

1 SEISMIC RISK MAPS FOR EUROCODE-8 DESIGNED BUILDINGS Thomas Ulrich1 , John Douglas2 , Caterina Negulescu3 There is currently a move towards seismic design maps that are risk-targeted (e.g. Luco et al of such maps relies on three independent inputs: a) seismic hazard curves derived using probabilistic seismic

488

Fall 2011 Course Syllabus Course number and title: CIVE 512 -Irrigation Systems Design  

E-Print Network [OSTI]

. Prerequisite: CIVE 425 ­ Soil and Water Engineering or CIVE 322/ENVE 322 - Basic Hydrology. Other related:00-3:00 in Engineering B-210. Course Objective: To provide an understanding of basic engineering principles of fixed and hand move systems. Week 7: Economic pipe design. Week 8: Pumps and system curves (design

489

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

490

A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas  

SciTech Connect (OSTI)

X-ray absorption spectroscopy is a powerful tool for the diagnosis of plasmas over a wide range of both temperature and density. However, such a measurement is often limited to probing plasmas with temperatures well below that of the x-ray source in order to avoid object plasma emission lines from obscuring important features of the absorption spectrum. This has excluded many plasmas from being investigated by this technique. We have developed an x-ray spectrometer that provides the ability to record absorption spectra from higher temperature plasmas than the usual approach allows without the risk of data contamination by line radiation emitted by the plasma under study. This is accomplished using a doubly curved mica crystal which is bent both elliptically and cylindrically. We present here the foundational work in the design and development of this spectrometer along with initial results obtained with an aluminum x-pinch as the object plasma.

Cahill, Adam D., E-mail: adc87@cornell.edu; Hoyt, Cad L.; Pikuz, Sergei A.; Shelkovenko, Tania; Hammer, David A. [Cornell University, Electrical and Computer Engineering, Ithaca, NY 14853 (United States)

2014-10-15T23:59:59.000Z

491

Analytical description of true stress-true strain curves for neutron-irradiated stainless austenitic steels  

SciTech Connect (OSTI)

This paper summarizes the results of an investigation for the deformation hardening behaviors of neutron-irradiated stainless steels in terms of true stress( ) true strain( ) curves. It is commonly accepted that the - curves are more informative for describing plastic flow, but there are few papers devoted to using the true curves for describing constitutive behaviors of materials. This study uses the true curves obtained from stainless steel samples irradiated to doses in the range of 0 55 dpa by various means: finite element calculation, optic extensomentry, and recalculation of engineering curves. It is shown that for the strain range 0 0.6 the true curves can be well described by the Swift equation: =k ( - 0)0.5. The influence of irradiation on the parameters of the Swift equation is investigated in detail. It is found that in most cases the k-parameter of this equation is not changed significantly by irradiation. Since large data scattering was observed for the 0-parameter, a modified Swift equation =k*( - 0 2/k2)0.5 was proposed and evaluated. This equation is based on the concept of zero stress, which is, in general, close to yield stress. The relationships among k, 0, and damage dose are discussed in detail, so as to more accurately describe the true curves for irradiated stainless steels.

Gussev, Maxim N [ORNL; Byun, Thak Sang [ORNL; Busby, Jeremy T [ORNL

2012-01-01T23:59:59.000Z

492

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

493

Fatigue Testing of Metallurgically-Bonded EBR-II Superheater Tubes  

SciTech Connect (OSTI)

Fatigue crack growth tests were performed on 2Cr-1Mo steel specimens machined from ex-service Experimental Breeder Reactor II (EBR-II) superheater duplex tubes. The tubes had been metallurgically bonded with a 100 m thick Ni interlayer; the specimens incorporated this bond layer. Tests were performed at room temperature in air and at 400C in air and humid Ar; cracks were grown at varied levels of constant ?K. Crack growth tests at a range of ?K were also performed on specimens machined from the shell of the superheater. In all conditions the presence of the Ni interlayer was found to result in a net retardation of growth as the crack passed through the interlayer. The mechanism of retardation was identified as a disruption of crack planarity and uniformity after passing through the porous interlayer. Full crack arrest was only observed in a single test performed at near-threshold ?K level (12 MPa?m) at 400C. In this case the crack tip was blunted by oxidation of the base steel at the steel-interlayer interface.

Terry C. Totemeier

2006-12-01T23:59:59.000Z

494

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

495

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

496

Preliminary structural design conceptualization for composite rotor for verdant power water current turbine  

SciTech Connect (OSTI)

Sandia National Laboratories (SNL) and Verdant Power Inc. (VPI) have partnered under a Cooperative Research and Development Agreement (CRADA) to develop a new kinetic hydropower rotor. The rotor features an improved hydrodynamic and structural design which features state-of-the-art technology developed for the wind industry. The new rotor will have higher energy capture, increased system reliability, and reduction of overall cost of energy. This project was divided into six tasks: (1) Composite Rotor Project Planning and Design Specification; (2) Baseline Fatigue Testing and Failure analysis; (3) Develop Blade/Rotor Performance Model; (4) Hydrofoil Survey and Selection; (5) FEM Structural Design; and (6) Develop Candidate Rotor Designs and Prepare Final Report.

Paquette, J. A.

2012-03-01T23:59:59.000Z

497

Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys  

SciTech Connect (OSTI)

We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

2006-02-07T23:59:59.000Z

498

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

499

Mechanism of fatigue in micron-scale films of polycrystalline silicon for microelectromechanical systems  

E-Print Network [OSTI]

to Microelectromechanical Systems ENGR 296A: Design Project (includes a literature review and a report) This program

Ritchie, Robert

500

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