Powered by Deep Web Technologies
Note: This page contains sample records for the topic "finite element method" 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.


1

Finite Volume Element Method  

E-Print Network [OSTI]

FVE is closely related to the control volume finite element method ... simple stencils, to apply to a fairly wide range of fluid flow equations, to effectively treat.

2003-12-06T23:59:59.000Z

2

INTRODUCTION TO THE FINITE ELEMENT METHOD  

E-Print Network [OSTI]

in popularity with the finite difference method in the areas of heat transfer and fluid mechanics. 1DRAFT Chapter 1 INTRODUCTION TO THE FINITE ELEMENT METHOD 1.1 Historical perspective: the origins of the finite el- ement method The finite element method constitutes a general tool for the numerical solution

California at Berkeley, University of

3

Generalized finite element method for Helmholtz equation  

E-Print Network [OSTI]

reduces the pollution effect due to wave number and we are able to obtain a highly accurate solution with a much smaller number of degrees-of-freedom compared with the classical Finite Element Method. The q-convergence of the handbook functions...

Hidajat, Realino Lulie

2009-05-15T23:59:59.000Z

4

Interval Finite Element Methods: New Directions Rafi Muhanna1  

E-Print Network [OSTI]

Interval Finite Element Methods: New Directions Rafi Muhanna1 , Vladik Kreinovich2 , Pavel Sol´in2 advanced numerical methods to tackle these problems, such as finite element methods (FEM). Lately, new advanced version of these methods have appeared, such as hierarchic higher-order finite element methods (hp

Kreinovich, Vladik

5

Introduction to Finite Element Methods \\Lambda Paul S. Heckbert  

E-Print Network [OSTI]

Introduction to Finite Element Methods \\Lambda Paul S. Heckbert Carnegie Mellon University Global be solved numerically. In this chapter we explain some of the basics of the finite element method Illumination course notes, SIGGRAPH '93, Anaheim, Aug. 1993 4­1 #12; 4­2 Introduction to Finite Element Methods

Treuille, Adrien

6

Compositional modeling of threephase flow with gravity using higherorder finite element methods  

E-Print Network [OSTI]

Compositional modeling of threephase flow with gravity using higherorder finite element methods using higherorder finite element methods. Gravity poses complications in modeling multiphase processes flow with gravity using higherorder finite element methods, Water Resour. Res., 47, W05511, doi:10

Firoozabadi, Abbas

7

PARTIALLY PENALIZED IMMERSED FINITE ELEMENT METHODS ...  

E-Print Network [OSTI]

each interface element, it uses IFE functions constructed with piecewise ...... strate this, we plot errors of a classic bilinear IFE solution and a NPP IFE solution in.

2015-01-05T23:59:59.000Z

8

Generalized finite element method for multiscale analysis  

E-Print Network [OSTI]

by the Partition of Unity Method (PUM). It is shown that the p-version of the Generalized FEM using mesh-based handbook functions is capable of achieving very high accuracy. It is also analyzed that the effect of the main factors affecting the accuracy...

Zhang, Lin

2004-11-15T23:59:59.000Z

9

Discontinuous Galerkin finite element methods for gradient plasticity.  

SciTech Connect (OSTI)

In this report we apply discontinuous Galerkin finite element methods to the equations of an incompatibility based formulation of gradient plasticity. The presentation is motivated with a brief overview of the description of dislocations within a crystal lattice. A tensor representing a measure of the incompatibility with the lattice is used in the formulation of a gradient plasticity model. This model is cast in a variational formulation, and discontinuous Galerkin machinery is employed to implement the formulation into a finite element code. Finally numerical examples of the model are shown.

Garikipati, Krishna. (University of Michigan, Ann Arbor, MI); Ostien, Jakob T.

2010-10-01T23:59:59.000Z

10

An Efficient Probabilistic Finite Element Method for Stochastic Groundwater Flow  

E-Print Network [OSTI]

of groundwater flow and transport from mathematical models involves considerable uncertainty due to the presenceAn Efficient Probabilistic Finite Element Method for Stochastic Groundwater Flow Harald Osnes Hans by nonlinear effects as oe Y approaches unity in more general domains. 1 #12; 1 Introduction The prediction

Osnes, Harald

11

The Mimetic Finite Element Method and the Virtual Element Method for elliptic problems with arbitrary regularity.  

SciTech Connect (OSTI)

We develop and analyze a new family of virtual element methods on unstructured polygonal meshes for the diffusion problem in primal form, that use arbitrarily regular discrete spaces V{sub h} {contained_in} C{sup {alpha}} {element_of} N. The degrees of freedom are (a) solution and derivative values of various degree at suitable nodes and (b) solution moments inside polygons. The convergence of the method is proven theoretically and an optimal error estimate is derived. The connection with the Mimetic Finite Difference method is also discussed. Numerical experiments confirm the convergence rate that is expected from the theory.

Manzini, Gianmarco [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

12

An application of stochastic finite element method in structural reliabiity  

E-Print Network [OSTI]

OF SCIENCE August 1993 Major Subject: Civil Engineering AN APPLICATION OF STOCHASTIC FINITE ELEMENT METHOD IN STRUCTURAL RELIABILITY A Thesis by SANJAY AGRAWAL Approved as to style and content by: Kostas apadimitriou (Chair of Committee) John M... of the beam on the buckling load. The statistical methodology can be efficiently used with available FORM/SORM reliability techniques to compute the probability of failure of the beam due to buckling. Random fields are used to quantify the modeling...

Agrawal, Sanjay

1993-01-01T23:59:59.000Z

13

Curved finite elements by the method of initial strains  

E-Print Network [OSTI]

, pp. 383-432. 2. Clough, R. W. , "Comparison of Three Dimensional Finite Elements, " Proceedin s of the S osium on A lication of Finite Element Mhd l. t''i~Et f, Vd6'ltUt ty, 1969, pp. 1-26. 3. Stricklin, J. A. , informal proposal submitted to Dr...

Leick, Roger Dale

1974-01-01T23:59:59.000Z

14

EXPANDED MIXED FINITE ELEMENT METHODS FOR QUASILINEAR SECOND ORDER ELLIPTIC PROBLEMS, II  

E-Print Network [OSTI]

EXPANDED MIXED FINITE ELEMENT METHODS FOR QUASILINEAR SECOND ORDER ELLIPTIC PROBLEMS, II Zhangxin coefficient times the gradient). Based on this formulation, mixed finite element approximations with low permeability and to the transport equation with small dispersion in groundwater modeling

15

A PARALLEL GEOMETRIC MULTIGRID METHOD FOR FINITE ELEMENTS ON OCTREE MESHES  

E-Print Network [OSTI]

A PARALLEL GEOMETRIC MULTIGRID METHOD FOR FINITE ELEMENTS ON OCTREE MESHES RAHUL S. SAMPATH for the discretized finite element operators and the intergrid transfer operations. The key component of our scheme it has a low setup cost. Key words. Geometric Multigrid, Finite Element Method, Linear Octrees, Adaptive

Biros, George

16

Finite size scaling for quantum criticality using the finite-element method  

E-Print Network [OSTI]

Finite size scaling for the Schr\\"{o}dinger equation is a systematic approach to calculate the quantum critical parameters for a given Hamiltonian. This approach has been shown to give very accurate results for critical parameters by using a systematic expansion with global basis-type functions. Recently, the finite element method was shown to be a powerful numerical method for ab initio electronic structure calculations with a variable real-space resolution. In this work, we demonstrate how to obtain quantum critical parameters by combining the finite element method (FEM) with finite size scaling (FSS) using different ab initio approximations and exact formulations. The critical parameters could be atomic nuclear charges, internuclear distances, electron density, disorder, lattice structure, and external fields for stability of atomic, molecular systems and quantum phase transitions of extended systems. To illustrate the effectiveness of this approach we provide detailed calculations of applying FEM to approximate solutions for the two-electron atom with varying nuclear charge; these include Hartree-Fock, density functional theory under the local density approximation, and an "exact"' formulation using FEM. We then use the FSS approach to determine its critical nuclear charge for stability; here, the size of the system is related to the number of elements used in the calculations. Results prove to be in good agreement with previous Slater-basis set calculations and demonstrate that it is possible to combine finite size scaling with the finite-element method by using ab initio calculations to obtain quantum critical parameters. The combined approach provides a promising first-principles approach to describe quantum phase transitions for materials and extended systems.

Edwin Antillon; Birgit Wehefritz-Kaufmann; Sabre Kais

2012-03-08T23:59:59.000Z

17

Control volume finite element method with multidimensional edge element Scharfetter-Gummel upwinding. Part 1, formulation.  

SciTech Connect (OSTI)

We develop a new formulation of the Control Volume Finite Element Method (CVFEM) with a multidimensional Scharfetter-Gummel (SG) upwinding for the drift-diffusion equations. The formulation uses standard nodal elements for the concentrations and expands the flux in terms of the lowest-order Nedelec H(curl; {Omega})-compatible finite element basis. The SG formula is applied to the edges of the elements to express the Nedelec element degree of freedom on this edge in terms of the nodal degrees of freedom associated with the endpoints of the edge. The resulting upwind flux incorporates the upwind effects from all edges and is defined at the interior of the element. This allows for accurate evaluation of integrals on the boundaries of the control volumes for arbitrary quadrilateral elements. The new formulation admits efficient implementation through a standard loop over the elements in the mesh followed by loops over the element nodes (associated with control volume fractions in the element) and element edges (associated with flux degrees of freedom). The quantities required for the SG formula can be precomputed and stored for each edge in the mesh for additional efficiency gains. For clarity the details are presented for two-dimensional quadrilateral grids. Extension to other element shapes and three dimensions is straightforward.

Bochev, Pavel Blagoveston

2011-06-01T23:59:59.000Z

18

Hypersonic heat transfer and anisotropic visualization with a higher order discontinuous Galerkin finite element method .  

E-Print Network [OSTI]

??Higher order discretizations of the Navier-Stokes equations promise greater accuracy than conventional computational aerodynamics methods. In particular, the discontinuous Galerkin (DG) finite element method has (more)

Quattrochi, Douglas J. (Douglas John)

2006-01-01T23:59:59.000Z

19

FINITE ELEMENT METHOD FOR SUBSURFACE HYDROLOGY USING A MIXED EXPLICIT-IMPLICIT SCHEME  

E-Print Network [OSTI]

METHOD FOR SUBSURFACE HYDROLOGY USING A MIXED EXPLICIT-arising in subsurface hydrology. These problems includeFinite Element Method in Hydrology," Int. Jour. Num. Meth.

Narasimhan, T.N.

2011-01-01T23:59:59.000Z

20

Developments in the method of finite spheres : efficiency and coupling to the traditional finite element method  

E-Print Network [OSTI]

In this thesis we develop some advances in the method of finite spheres which is a truly meshless numerical technique for the solution of boundary value problems on geometrically complex domains. We present the development ...

Hong, Jung-Wuk, 1970-

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Uncoupled thermoelastic structural response by the finite element method  

E-Print Network [OSTI]

Numerical Considerations Banded equation format Newton iteration Finite difference time integration schemes Interpolation of material properties 12 20 21 23 23 24 25 28 33 33 34 34 34 . . 37 39 CODE VERIFICATION Steady-State Heat... element mesh for the transient uniaxial bar with internal heat generation and radiation ~ 71 24 Internal temperatures with time for various values of heat generation 73 25 Surface temperatures with time for various values of heat generation 74 LIST...

Linn, William Ray

1982-01-01T23:59:59.000Z

22

Adaptive finite element methods for PDE-constrained optimal control problems  

E-Print Network [OSTI]

Adaptive finite element methods for PDE-constrained optimal control problems R. Becker1 , M. Braack is discretized by a finite element Galerkin method. The accuracy of the discretization is controlled by residual of heat transfer, fluid flow and parameter estimation. The contents of this article is as follows

23

LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS  

E-Print Network [OSTI]

LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS FELIPE LEPE for Timo- shenko beams. It is known that standard finite elements applied to this model lead to wrong results when the thickness of the beam t is small. Here, we consider a mixed formulation in terms

Rodríguez, Rodolfo

24

Hypersonic heat transfer and anisotropic visualization with a higher order discontinuous Galerkin finite element method  

E-Print Network [OSTI]

Higher order discretizations of the Navier-Stokes equations promise greater accuracy than conventional computational aerodynamics methods. In particular, the discontinuous Galerkin (DG) finite element method has O(hP+l) ...

Quattrochi, Douglas J. (Douglas John)

2006-01-01T23:59:59.000Z

25

A comparison of spectral element and finite difference methods using statically refined  

E-Print Network [OSTI]

A comparison of spectral element and finite difference methods using statically refined elements on a refined grid, using spectral method (polynomials of order p). · Accuracy convergence rate refinement dynamically or statically. Why considering spectral element? #12;Motivation · Since the main

Ng, Chung-Sang

26

Interval Finite Element Methods: New Directions Rafi Muhanna 1 , Vladik Kreinovich 2 , Pavel Sol'in 2 ,  

E-Print Network [OSTI]

Interval Finite Element Methods: New Directions Rafi Muhanna 1 , Vladik Kreinovich 2 , Pavel Ÿ Sol advanced numerical methods to tackle these problems, such as finite element methods (FEM). Lately, new advanced version of these methods have appeared, such as hierarchic higher­order finite element methods (hp

Ward, Karen

27

DIRECT AND INVERSE APPROXIMATION THEOREMS FOR THE p-VERSION OF THE FINITE ELEMENT METHOD IN THE  

E-Print Network [OSTI]

of the finite element method, for example, MSC/PROBE, FIESTA, MECHANICA, PHLEX, STRESSCHECK, and STRIPE. In 1980

Guo, Benqi

28

Thermo-Poroelastic Modeling of Reservoir Stimulation and Microseismicity Using Finite Element Method with Damage Mechanics  

E-Print Network [OSTI]

, changing rock permeability. In this work, two- and three-dimensional finite element methods were developed to simulate coupled reservoirs with damage mechanics and stress-dependent permeability. The model considers the influence of fluid flow, temperature...

Lee, Sang Hoon

2012-02-14T23:59:59.000Z

29

A Family of Uniform Strain Tetrahedral Elements and a Method for Connecting Dissimilar Finite Element Meshes  

SciTech Connect (OSTI)

This report documents a collection of papers on a family of uniform strain tetrahedral finite elements and their connection to different element types. Also included in the report are two papers which address the general problem of connecting dissimilar meshes in two and three dimensions. Much of the work presented here was motivated by the development of the tetrahedral element described in the report "A Suitable Low-Order, Eight-Node Tetrahedral Finite Element For Solids," by S. W. Key {ital et al.}, SAND98-0756, March 1998. Two basic issues addressed by the papers are: (1) the performance of alternative tetrahedral elements with uniform strain and enhanced uniform strain formulations, and (2) the proper connection of tetrahedral and other element types when two meshes are "tied" together to represent a single continuous domain.

Dohrmann, C.R.; Heinstein, M.W.; Jung, J.; Key, S.W.

1999-01-01T23:59:59.000Z

30

Determination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method  

E-Print Network [OSTI]

Determination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method X Received in revised form 21 June 2012 Accepted 11 August 2012 Keywords: Fracture toughness Cohesive finite is to develop a micromechanical approach for determining the fracture toughness. A phase-field model for grain

Chen, Long-Qing

31

A bibliography on finite element and related methods analysis in reactor physics computations (1971--1997)  

SciTech Connect (OSTI)

This bibliography provides a list of references on finite element and related methods analysis in reactor physics computations. These references have been published in scientific journals, conference proceedings, technical reports, thesis/dissertations and as chapters in reference books from 1971 to the present. Both English and non-English references are included. All references contained in the bibliography are sorted alphabetically by the first author`s name and a subsort by date of publication. The majority of the references relate to reactor physics analysis using the finite element method. Related topics include the boundary element method, the boundary integral method, and the global element method. All aspects of reactor physics computations relating to these methods are included: diffusion theory, deterministic radiation and neutron transport theory, kinetics, fusion research, particle tracking in finite element grids, and applications. For user convenience, many of the listed references have been categorized. The list of references is not all inclusive. In general, nodal methods were purposely excluded, although a few references do demonstrate characteristics of finite element methodology using nodal methods (usually as a non-conforming element basis). This area could be expanded. The author is aware of several other references (conferences, thesis/dissertations, etc.) that were not able to be independently tracked using available resources and thus were not included in this listing.

Carpenter, D.C.

1998-01-01T23:59:59.000Z

32

Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method  

E-Print Network [OSTI]

Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method Gang Wang Research Associate University of Nebraska Lincoln Mingsheng Liu Professor University of Nebraska Lincoln David E. Claridge Professor Texas A... be decoupled using a constant sensible heat ratio (SHR) and the saturation humidity ratio vs. temperature curve can be treated as linear in a small area corresponding to a finite element of the coil. This paper presents the decoupled cooling coil model...

Wang, G.; Liu, M.

2005-01-01T23:59:59.000Z

33

NUMERICAL MODELING OF CONTAMINANT TRANSPORT IN FRACTURED POROUS MEDIA USING MIXED FINITE ELEMENT AND FINITE VOLUME METHODS  

SciTech Connect (OSTI)

A mathematical model for contaminant species passing through fractured porous media is presented. In the numerical model, we combine two locally conservative methods, i.e. mixed finite element (MFE) and the finite volume methods. Adaptive triangle mesh is used for effective treatment of the fractures. A hybrid MFE method is employed to provide an accurate approximation of velocities field for both the fractures and matrix which are crucial to the convection part of the transport equation. The finite volume method and the standard MFE method are used to approximate the convection and dispersion terms respectively. The model is used to investigate the interaction of adsorption with transport and to extract information on effective adsorption distribution coefficients. Numerical examples in different fractured media illustrate the robustness and efficiency of the proposed numerical model.

Taylor, G.; Dong, C.; Sun, S.

2010-03-18T23:59:59.000Z

34

A VECTOR FINITE ELEMENT TIME-DOMAIN METHOD FOR ...  

E-Print Network [OSTI]

and to conserve energy and charge for arbitrary hexahedral grids. ... experiments are performed to determine the accuracy and efficiency of the method.

SIAM (#1) 1035 2001 Apr 10 12:32:38

2001-08-14T23:59:59.000Z

35

The piecewise linear discontinuous finite element method applied to the RZ and XYZ transport equations  

E-Print Network [OSTI]

of the Piecewise Linear Discontinuous Finite Element Method (PWLD) applied to the particle transport equation in two-dimensional cylindrical (RZ) and three-dimensional Cartesian (XYZ) geometries. We have designed this method to be applicable to radiative... ..................................................... 12 Coupling the radiation transport equation to the Euler equations.. 16 Limit of the radiative transfer equations ........................................ 19 Summary...

Bailey, Teresa S

2008-10-10T23:59:59.000Z

36

Mixed finite element methods for incompressible flow: Stationary ...  

E-Print Network [OSTI]

May 14, 2009 ... 0, (conservation of mass) ... Contract grant sponsor: U.S. Department of Energy by University of California .... We use the standard notations and definitions for the Sobolev ...... minimum residual method applied to the system.

2010-04-14T23:59:59.000Z

37

stabilized finite element methods for coupled geomechanics and ...  

E-Print Network [OSTI]

geomechanics and reservoir fluid flow simulations. There are, however ... coupled methods. The comparisons demonstrate consistent results on homogeneous ..... C Software Design. 153 ..... source of reservoir energy (Ruddy et al. 1989).

38

Deforming fluid domains within the finite element method: Five mesh-based tracking methods in comparison  

E-Print Network [OSTI]

Fluid flow applications can involve a number of coupled problems. One is the simulation of free-surface flows, which require the solution of a free-boundary problem. Within this problem, the governing equations of fluid flow are coupled with a domain deformation approach. This work reviews five of those approaches: interface tracking using a boundary-conforming mesh and, in the interface capturing context, the level-set method, the volume-of-fluid method, particle methods, as well as the phase-field method. The history of each method is presented in combination with the most recent developments in the field. Particularly, the topics of extended finite elements (XFEM) and NURBS-based methods, such as Isogeometric Analysis (IGA), are addressed. For illustration purposes, two applications have been chosen: two-phase flow involving drops or bubbles and sloshing tanks. The challenges of these applications, such as the geometrically correct representation of the free surface or the incorporation of surface tension ...

Elgeti, Stefanie

2015-01-01T23:59:59.000Z

39

Computation of mode II linear elastic stress intensity factor using the p-version of the finite element method  

SciTech Connect (OSTI)

It has been proven that the p-version of the finite element method results in a higher accuracy for a given mesh compared to the h-version of the finite element method. This investigation demonstrates the accuracy of the displacement and stress field methods in the vicinity of the crack tip using the p-version of the finite element method to compute the linear elastic stress intensity factor. The stress intensity factor for mode II is computed for an edge crack panel using stress and displacement methods and is compared to the analytical solution.

Orth, N.J.; Sansguiri, A.M. [Lamar Univ., Beaumont, TX (United States). Dept. of Mechanical Engineering; Orth, F.J. [Edison Welding Inst., Columbus, OH (United States). Structural Integrity Section

1995-08-01T23:59:59.000Z

40

HYPERBOLIC DIFFERENTIAL The classical Bubnov-Galerkin finite element method is optimal in the sense of the best ap-  

E-Print Network [OSTI]

-Galerkin method and subsequently discretize the resulting equations by N + 1 equally-sized finite elementsDRAFT Chapter 9 HYPERBOLIC DIFFERENTIAL EQUATIONS The classical Bubnov-Galerkin finite element equations. In many problems of mechan- ics and convective heat transfer where convection dominates diffusion

California at Berkeley, University of

Note: This page contains sample records for the topic "finite element method" 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

Permeability computation on a REV with an immersed finite element method  

SciTech Connect (OSTI)

An efficient method to compute permeability of fibrous media is presented. An immersed domain approach is used to represent the porous material at its microscopic scale and the flow motion is computed with a stabilized mixed finite element method. Therefore the Stokes equation is solved on the whole domain (including solid part) using a penalty method. The accuracy is controlled by refining the mesh around the solid-fluid interface defined by a level set function. Using homogenisation techniques, the permeability of a representative elementary volume (REV) is computed. The computed permeabilities of regular fibre packings are compared to classical analytical relations found in the bibliography.

Laure, P. [Laboratoire J.-A. Dieudonne, CNRS UMR 6621, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice, Cedex 02 (France); Puaux, G.; Silva, L.; Vincent, M. [MINES ParisTech, CEMEF-Centre de Mise en Forme des Materiaux, CNRS UMR 7635, BP 207 1 rue Claude, Daunesse 06904 Sophia Antipolis cedex (France)

2011-05-04T23:59:59.000Z

42

Use of the iterative solution method for coupled finite element and boundary element modeling; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

Tunnels buried deep within the earth constitute an important class geomechanics problems. Two numerical techniques used for the analysis of geomechanics problems, the finite element method and the boundary element method, have complementary characteristics for applications to problems of this type. The usefulness of combining these two methods for use as a geomechanics analysis tool has been recognized for some time, and a number of coupling techniques have been proposed. However, not all of them lend themselves to efficient computational implementations for large-scale problems. This report examines a coupling technique that can form the basis for an efficient analysis tool for large scale geomechanics problems through the use of an iterative equation solver.

Koteras, J.R.

1993-07-01T23:59:59.000Z

43

An h-adaptive finite element method for turbulent heat transfer  

SciTech Connect (OSTI)

A two-equation turbulence closure model (k-{omega}) using an h-adaptive grid technique and finite element method (FEM) has been developed to simulate low Mach flow and heat transfer. These flows are applicable to many flows in engineering and environmental sciences. Of particular interest in the engineering modeling areas are: combustion, solidification, and heat exchanger design. Flows for indoor air quality modeling and atmospheric pollution transport are typical types of environmental flows modeled with this method. The numerical method is based on a hybrid finite element model using an equal-order projection process. The model includes thermal and species transport, localized mesh refinement (h-adaptive) and Petrov-Galerkin weighting for the stabilizing the advection. This work develops the continuum model of a two-equation turbulence closure method. The fractional step solution method is stated along with the h-adaptive grid method (Carrington and Pepper, 2002). Solutions are presented for 2d flow over a backward-facing step.

Carriington, David B [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

44

Probabilistic finite element analysis of marine risers  

E-Print Network [OSTI]

Review 1. 2 Research Study 10 2 FORMULATION OF THE SECOND ? MOMENT ANALYSIS METHOD 13 2. 1 Finite Element Equations 2. 2 Random Vector Formulation 2. 3 The Correlation Function 2. 4 Random Field Discretization 2. 5 Taylor Series Expansion 2. 6... ILLUSTRATIVE EXAMPLE. . . . . . . . . . . . . . . . . . 4 APPLICATION OF PROBABILISTIC FINITE ELEMENT METHODS TO MARINE RISER ANALYSES 4. 1 Finite Element Model . 4. 1. 1 Formulation of the Equation of Motion 4. 1. 2 Finite Element Discretization 4. 1. 3...

Leder, H. Vern

1990-01-01T23:59:59.000Z

45

Adaptive Mesh Refinement Solution Techniques for the Multigroup SN Transport Equation Using a Higher-Order Discontinuous Finite Element Method  

E-Print Network [OSTI]

In this dissertation, we develop Adaptive Mesh Refinement (AMR) techniques for the steady-state multigroup SN neutron transport equation using a higher-order Discontinuous Galerkin Finite Element Method (DGFEM). We propose two error estimations, a...

Wang, Yaqi

2010-01-16T23:59:59.000Z

46

Higher-order adaptive finite-element methods for KohnSham density functional theory  

SciTech Connect (OSTI)

We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of KohnSham density-functional theory (DFT). To this end, we develop an a priori mesh-adaption technique to construct a close to optimal finite-element discretization of the problem. We further propose an efficient solution strategy for solving the discrete eigenvalue problem by using spectral finite-elements in conjunction with GaussLobatto quadrature, and a Chebyshev acceleration technique for computing the occupied eigenspace. The proposed approach has been observed to provide a staggering 100200-fold computational advantage over the solution of a generalized eigenvalue problem. Using the proposed solution procedure, we investigate the computational efficiency afforded by higher-order finite-element discretizations of the KohnSham DFT problem. Our studies suggest that staggering computational savingsof the order of 1000-foldrelative to linear finite-elements can be realized, for both all-electron and local pseudopotential calculations, by using higher-order finite-element discretizations. On all the benchmark systems studied, we observe diminishing returns in computational savings beyond the sixth-order for accuracies commensurate with chemical accuracy, suggesting that the hexic spectral-element may be an optimal choice for the finite-element discretization of the KohnSham DFT problem. A comparative study of the computational efficiency of the proposed higher-order finite-element discretizations suggests that the performance of finite-element basis is competing with the plane-wave discretization for non-periodic local pseudopotential calculations, and compares to the Gaussian basis for all-electron calculations to within an order of magnitude. Further, we demonstrate the capability of the proposed approach to compute the electronic structure of a metallic system containing 1688 atoms using modest computational resources, and good scalability of the present implementation up to 192 processors.

Motamarri, P. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Nowak, M.R. [Department of Electrical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Electrical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Leiter, K.; Knap, J. [U.S. Army Research Labs, Aberdeen Proving Ground, Aberdeen, MD 21001 (United States)] [U.S. Army Research Labs, Aberdeen Proving Ground, Aberdeen, MD 21001 (United States); Gavini, V., E-mail: vikramg@umich.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-11-15T23:59:59.000Z

47

Simulation of the ultrasonic array response from real branched cracks using an efficient finite element method  

SciTech Connect (OSTI)

A hybrid model to simulate the ultrasonic array response from stress corrosion cracks is presented. These cracks are branched and difficult to detect so the model is required to enable optimization of an array design. An efficient frequency-domain finite element method is described and selected to simulate the ultrasonic scattering. Experimental validation results are presented, followed by an example of the simulated ultrasonic array response from a real stress corrosion crack whose geometry is obtained from an X-ray Computed Tomography image. A simulation-assisted array design methodology, which includes the model and use of real crack geometries, is proposed.

Felice, Maria V. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, United Kingdom and Rolls-Royce plc., Bristol BS34 7QE (United Kingdom); Velichko, Alexander; Wilcox, Paul D. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Barden, Tim J.; Dunhill, Tony K. [Rolls-Royce plc., Bristol BS34 7QE (United Kingdom)

2014-02-18T23:59:59.000Z

48

LOCAL ENERGY ESTIMATES FOR THE FINITE ELEMENT METHOD ON SHARPLY VARYING GRIDS  

E-Print Network [OSTI]

. We present local a priori energy estimates that are valid on shape regular grids, an assumption which subdomains under the assumption that the finite element grid is quasi-uniform. Such local energy estimates element theory. Here we prove local energy error estimates under the assumption that the fi- nite element

Demlow, Alan

49

Modeling a bender element test using Abaqus Finite Element Program  

E-Print Network [OSTI]

Finite Element Methods hold promise for modeling the behavior of an unsaturated soil specimen subjected to bender element agitation. The immediate objective of this research project is to reproduce a bender element test ...

Johnson, Sean (Sean Michael)

2011-01-01T23:59:59.000Z

50

LOCAL ENERGY ESTIMATES FOR THE FINITE ELEMENT METHOD ON SHARPLY VARYING GRIDS  

E-Print Network [OSTI]

. We present local a priori energy estimates that are valid on shape regular grids, an assumption which subdomains under the assumption that the finite element grid is quasi-uniform. Such local energy estimates. Here we prove local energy error estimates under the assumption that the fi- nite element triangulation

Guzmán, Johnny

51

Process metallurgy simulation for metal drawing process optimization by using two-scale finite element method  

SciTech Connect (OSTI)

We developed two-scale FE analysis procedure based on the crystallographic homogenization method by considering the hierarchical structure of poly-crystal aluminium alloy metal. It can be characterized as the combination of two-scale structure, such as the microscopic polycrystal structure and the macroscopic elastic plastic continuum. Micro polycrystal structure can be modeled as a three dimensional representative volume element (RVE). RVE is featured as by 333 eight-nodes solid finite elements, which has 216 crystal orientations. This FE analysis code can predict the deformation, strain and stress evolutions in the wire drawing processes in the macro- scales, and further the crystal texture and hardening evolutions in the micro-scale. In this study, we analyzed the texture evolution in the wire drawing processes by our two-scale FE analysis code under conditions of various drawing angles of dice. We evaluates the texture evolution in the surface and center regions of the wire cross section, and to clarify the effects of processing conditions on the texture evolution.

Nakamachi, Eiji; Yoshida, Takashi; Yamaguchi, Toshihiko; Morita, Yusuke [Dept. of Biomedical Engineering, Doshisha Univ., Kyotanabe, Kyoto, 610-0394 (Japan); Kuramae, Hiroyuki [Dept. of Technol. Management, Osaka Institute of Technol., Asahiku, Osaka, 535-8585 (Japan); Morimoto, Hideo [Furukawa Electric Co. Ltd., Okano, Nishiku, Yokohama, Kanagawa, 220-0073 (Japan)

2014-10-06T23:59:59.000Z

52

Chapter 17 in Encyclopedia of Computational Mechanics, Volume 3: Fluids Finite Element Methods for Fluid Dynamics with  

E-Print Network [OSTI]

Chapter 17 in Encyclopedia of Computational Mechanics, Volume 3: Fluids Finite Element Methods surfaces, two-fluid interfaces, fluid­object and fluid­structure in- teractions, and moving mechanical in Encyclopedia of Computational Mechanics, Volume 3: Fluids (eds. E. Stein, R. De Borst and T.J.R. Hughes), John

Tezduyar, Tayfun E.

53

Visualization methods for high-resolution, transient, 3-D, finite element situations  

SciTech Connect (OSTI)

Scientific visualization is the process whereby numerical data is transformed into a visual form to augment the process of discovery and understanding. Visualizing the data generated by large-scale, transient, three-dimensional finite element simulations poses many challenges due to geometric complexity, the presence of multiple materials and multiple element types, and the inherent unstructured nature of the meshes. In this paper, the direct use of finite element data structures, nodal assembly procedures, and element interpolants for volumetric adaptive surface extraction, surface rendering, vector grids and particle tracing is discussed. A brief description of a {open_quotes}direct-to-disk{close_quotes} animation system is presented, and case studies which demonstrate the use of isosurfaces, vector plots, cutting planes, reference surfaces and particle tracing are then discussed in the context of several case studies for transient incompressible viscous flow, and acoustic fluid-structure interaction simulations. An overview of the implications of massively parallel computers on visualization is presented to highlight the issues in parallel visualization methodology, algorithms. data locality and the ultimate requirements for temporary and archival data storage and network bandwidth.

Christon, M.A.

1995-01-10T23:59:59.000Z

54

DOLFIN: Automated Finite Element Computing  

E-Print Network [OSTI]

delec 1980]. (4) L2-conforming finite elements: (a) DGq, arbitrary degree discontinuous Lagrange elements; and (b) CR1, first degree CrouzeixRaviart5 elements [Crouzeix and Raviart 1973]. Arbitrary combinations of the above elements may be used to define...

Logg, Anders; Wells, G N

2009-01-01T23:59:59.000Z

55

electroseismic monitoring of co2 sequestration: a finite element ...  

E-Print Network [OSTI]

Keywords: Electroseismic Modeling, Poroelasticity, CO2 sequestration, Finite element methods. 2000 AMS ... carbon dioxide emissisons into the atmosphere.

Fabio Zyserman

56

Numerical Stochastic Homogenization Method and Multiscale Stochastic Finite Element Method - A Paradigm for Multiscale Computation of Stochastic PDEs  

SciTech Connect (OSTI)

Multiscale modeling of stochastic systems, or uncertainty quantization of multiscale modeling is becoming an emerging research frontier, with rapidly growing engineering applications in nanotechnology, biotechnology, advanced materials, and geo-systems, etc. While tremendous efforts have been devoted to either stochastic methods or multiscale methods, little combined work had been done on integration of multiscale and stochastic methods, and there was no method formally available to tackle multiscale problems involving uncertainties. By developing an innovative Multiscale Stochastic Finite Element Method (MSFEM), this research has made a ground-breaking contribution to the emerging field of Multiscale Stochastic Modeling (MSM) (Fig 1). The theory of MSFEM basically decomposes a boundary value problem of random microstructure into a slow scale deterministic problem and a fast scale stochastic one. The slow scale problem corresponds to common engineering modeling practices where fine-scale microstructure is approximated by certain effective constitutive constants, which can be solved by using standard numerical solvers. The fast scale problem evaluates fluctuations of local quantities due to random microstructure, which is important for scale-coupling systems and particularly those involving failure mechanisms. The Green-function-based fast-scale solver developed in this research overcomes the curse-of-dimensionality commonly met in conventional approaches, by proposing a random field-based orthogonal expansion approach. The MSFEM formulated in this project paves the way to deliver the first computational tool/software on uncertainty quantification of multiscale systems. The applications of MSFEM on engineering problems will directly enhance our modeling capability on materials science (composite materials, nanostructures), geophysics (porous media, earthquake), biological systems (biological tissues, bones, protein folding). Continuous development of MSFEM will further contribute to the establishment of Multiscale Stochastic Modeling strategy, and thereby potentially to bring paradigm-shifting changes to simulation and modeling of complex systems cutting across multidisciplinary fields.

X. Frank Xu

2010-03-30T23:59:59.000Z

57

THE MORTAR FINITE ELEMENT METHOD FOR 3D MAXWELL EQUATIONS: FIRST RESULTS  

E-Print Network [OSTI]

of the mortar element method to the numerical solution of Maxwell's equations (in wave form) by H; accepted for publication (in revised form) February 2, 2001; published electronically July 31, 2001. This work has been partially supported by Istituto di Analisi Numerica del Centro Nazionale delle Ricerche

Buffa, Annalisa

58

PHYSICAL REVIEW E 85, 036706 (2012) Finite-size scaling for quantum criticality using the finite-element method  

E-Print Network [OSTI]

initio approximations and exact formulations. The critical parameters could be atomic nuclear charges, and an "exact" formulation using FEM. We then use the FSS approach to determine its critical nuclear chargePHYSICAL REVIEW E 85, 036706 (2012) Finite-size scaling for quantum criticality using the finite

Kais, Sabre

59

A multiscale preconditioner for stochastic mortar mixed finite elements  

E-Print Network [OSTI]

physical models in different subdomains. The mortar finite element method is a generalization is the stochastic collocation method [4,40,39]. It combines a finite element discretiza- tion in physical space the approximation properties of the stochastic finite element method [5,37], making it more efficient than MCS

Yotov, Ivan

60

An analysis of the effect of coupling between temperature rise and light distribution in laser irradiated tissue using finite element and Monte-Carlo methods  

E-Print Network [OSTI]

AN ANALYSIS OF THE EFFECT OF COUPLING BETWEEN TEMPERATURE RISE AND LIGHT DISTRIBUTION IN LASER IRRADIATED TISSUE USING FINITE ELEMENT AND MONTE- CARLO METHODS A Thesis BEOP-MIN KIM Submitted to the Office of Graduate Studies of Texas A... FINITE ELEMENT AND MONTE- CARLO METHODS A Thesis BEOP-MIN KIM Approved as to style and content by: Sohi Rastegar (Chair of Committee) Gerald E. Miller (member) He F. Taylor (member) . Kemble ennett (Head of Department) August 1991 ABSTRACT...

Kim, Beop-Min

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Numerical simulation of two-phase flow in discrete fractures using Rayleigh-Ritz finite element method  

E-Print Network [OSTI]

Spontaneous imbibition plays a very important role in the displacement mechanism of non-wetting fluid in naturally fractured reservoirs. We developed a new 2D two-phase finite element numerical model, as available commercial simulators cannot...

Kaul, Sandeep P.

2004-09-30T23:59:59.000Z

62

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite Element Method  

E-Print Network [OSTI]

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin;Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite used to predict heat transfer to a cylinder in a hypersonic flow. The strong shock is captured

Peraire, Jaime

63

Calculation of demagnetization curves of NdFeB-magnets using the finite-element-method  

SciTech Connect (OSTI)

A method is developed, which allows to investigate the influence of magnetostatic coupling of structural details on the demagnetization curve within a two dimensional model. In contrast to former methods, which assigned to each grain one value of magnetic field and one value of nucleation field only, this method takes into account the spatial distribution of these fields. It considers not only the coupling between adjacent grains but also the effect of distant grains. The nucleation fields along the boundary of the grains are generated by a statistical method. The magnetic field is calculated by FEM.

Binner, A.; Roth, S.; Stiller, C. [Inst. fuer Festkoerper- und Werkstofforschung Dresden e.V (Germany)] [Inst. fuer Festkoerper- und Werkstofforschung Dresden e.V (Germany)

1994-03-01T23:59:59.000Z

64

A 3D finite element method for flexible multibody Johannes Gerstmayr, Joachim Schoberl  

E-Print Network [OSTI]

-blade of a helicopter or the stability of a satellite with highly flexible solar panels, see Bremer [5]. While most methods. This is applicable for the case for several engineering applications, like a gear unit

Schoeberl, Joachim

65

A performance study of plane wave finite element methods with a Pad-type artificial boundary condition in acoustic scattering  

E-Print Network [OSTI]

Keywords: Acoustic scattering Finite element Plane wave Pollution High-frequency Artificial boundary condition in acoustic scattering R. Kechroud a , A. Soulaimani a , X. Antoine b,c,* a ?cole de Technologie are found. Indeed, it is well known that pollution effects [10­12] arise in the standard FEM, limiting its

Antoine, Xavier - Institut de Mathématiques ?lie Cartan, Université Henri Poincaré

66

PERFORMANCE OF FULLY-COUPLED DOMAIN DECOMPOSITION PRECONDITIONERS for FINITE ELEMENT TRANSPORT / REACTION SIMULATIONS1  

E-Print Network [OSTI]

element simulation of strongly coupled fluid flow, heat transfer, and mass transfer with non methods, stabilized finite element methods. 1. INTRODUCTION Modern computational fluid dynamics flows with unstructured mesh finite element methods. These flow problems are characterized by both

Tuminaro, Ray S.

67

THE FINITE RAY ELEMENT METHOD FOR THE HELMHOLTZ EQUATION OF SCATTERING: FIRST NUMERICAL EXPERIMENTS \\Lambda  

E-Print Network [OSTI]

than on the wave number; in the high frequency approximation, the method resembles geometrical optics ; š is outer normal of \\Omega\\Gamma This formulation of the boundary conditions includes ffl ff(x) = 0. Find p 2 V , V = H 1(\\Omega\\Gamma3 such that \\Gamma Z \\Omega rprv + Z \\Omega K 2 pv + Z @\\Omega g

Mandel, Jan

68

Uzawa conjugate gradient method for the Stokes problem: Matlab implementation with P1-iso-P2/P1 finite element  

E-Print Network [OSTI]

Uzawa conjugate gradient method for the Stokes problem: Matlab implementation with P1-iso-P2/P1 implementation of the Uzawa Conjugate gradient algorithm for the generalized Stokes problem with a P1-iso-P2/P1 for the generalized Stokes problem using the P1-iso-P2/P1 finite element. The Uzawa scheme is a decomposition

Frey, Pascal

69

Finite element analysis of human joints  

SciTech Connect (OSTI)

Our work focuses on the development of finite element models (FEMs) that describe the biomechanics of human joints. Finite element modeling is becoming a standard tool in industrial applications. In highly complex problems such as those found in biomechanics research, however, the full potential of FEMs is just beginning to be explored, due to the absence of precise, high resolution medical data and the difficulties encountered in converting these enormous datasets into a form that is usable in FEMs. With increasing computing speed and memory available, it is now feasible to address these challenges. We address the first by acquiring data with a high resolution C-ray CT scanner and the latter by developing semi-automated method for generating the volumetric meshes used in the FEM. Issues related to tomographic reconstruction, volume segmentation, the use of extracted surfaces to generate volumetric hexahedral meshes, and applications of the FEM are described.

Bossart, P.L.; Hollerbach, K.

1996-09-01T23:59:59.000Z

70

Finite Element Modeling of Drilling Using DEFORM  

E-Print Network [OSTI]

Vijayaraghavan, A. (2005), Drilling of Fiber- ReinforcedFINITE ELEMENT MODELING OF DRILLING USING DEFORM J. Gardner,of Comprehensive Drilling Simulation Tool ABSTRACT DEFORM-

Gardner, Joel D.; Dornfeld, David

2006-01-01T23:59:59.000Z

71

Finite element approximation of coupled seismic and ...  

E-Print Network [OSTI]

layer, having a thickness of about 10 nm. Finite element approximation of coupled seismic and electromagnetic waves in gas hydrate-bearing sediments p.

zyserman

72

Dynamic analysis of mechanisms by finite elements  

SciTech Connect (OSTI)

The need to increase productivity in order to decrease manufacturing costs lead to an increase in the working speeds of machines and mechanical systems used in manufacturing. A method is presented for investigating the dynamics of mechanisms with elastic links. Finite element method is used in the formulation of the dynamic problem. Modal transformation is used in order to reduce the number of equations of motion. Using the presented technique, elastic and rigid body motions of mechanism links are solved simultaneously. The presented method may be applied to spatial and open loop mechanisms including robot manipulators as well.

Botsali, F.M.; Uenuevar, A. [Selcuk Univ., Konya (Turkey). Mechanical Engineering Dept.

1996-11-01T23:59:59.000Z

73

Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method  

E-Print Network [OSTI]

equation. Using a new moving-boundary element partition methodology (EPM), fracture propagation through heterogeneous media is predicted simply and efficiently. The method allows coupling fluid flow and rock deformation, and fracture propagation using...

Min, Kyoung

2013-07-16T23:59:59.000Z

74

A weighted reverse Cuthill-McKee procedure for finite element method algorithms to solve strongly anisotropic electrodynamic problems  

SciTech Connect (OSTI)

This paper presents a technique for improving the convergence rate of a generalized minimum residual (GMRES) algorithm applied for the solution of a algebraic system produced by the discretization of an electrodynamic problem with a tensorial electrical conductivity. The electrodynamic solver considered in this work is a part of a magnetohydrodynamic (MHD) code in the low magnetic Reynolds number approximation. The code has been developed for the analysis of MHD interaction during the re-entry phase of a space vehicle. This application is a promising technique intensively investigated for the shock mitigation and the vehicle control in the higher layers of a planetary atmosphere. The medium in the considered application is a low density plasma, characterized by a tensorial conductivity. This is a result of the behavior of the free electric charges, which tend to drift in a direction perpendicular both to the electric field and to the magnetic field. In the given approximation, the electrodynamics is described by an elliptical partial differential equation, which is solved by means of a finite element approach. The linear system obtained by discretizing the problem is solved by means of a GMRES iterative method with an incomplete LU factorization threshold preconditioning. The convergence of the solver appears to be strongly affected by the tensorial characteristic of the conductivity. In order to deal with this feature, the bandwidth reduction in the coefficient matrix is considered and a novel technique is proposed and discussed. First, the standard reverse Cuthill-McKee (RCM) procedure has been applied to the problem. Then a modification of the RCM procedure (the weighted RCM procedure, WRCM) has been developed. In the last approach, the reordering is performed taking into account the relation between the mesh geometry and the magnetic field direction. In order to investigate the effectiveness of the methods, two cases are considered. The RCM and WRCM procedures has successfully improved the convergence rate of the GMRES solver. For strong anisotropies, the WRCM procedure appears to have a higher convergence rate. The same behavior is shown when applying the methods to the rebuilding of an hypersonic MHD experiment.

Cristofolini, Andrea; Latini, Chiara; Borghi, Carlo A. [Department of Electrical Engineering, University of Bologna, Viale Risorgimento 2, 40136 Bologna (Italy)

2011-02-01T23:59:59.000Z

75

Smooth exterior complex-scaling, full-angular-momentum, and three-dimensional finite-element method applied to doubly excited states of helium  

SciTech Connect (OSTI)

A technique based on the total-angular-momentum representation the smooth exterior complex-scaling procedure, and the three-dimensional finite-element method, is applied to calculations of S, P, and D resonant, so-called doubly excited, states of the helium atom. The resonances are calculated with an accuracy better than 10{sup -5} a.u. The applicability of an extrapolation procedure to complex energies is analyzed.

Elander, Nils [Department of Physics, Stockholm University, Alba Nova University Center, SE-106 91 Stockholm (Sweden); Levin, Sergey [Department of Physics, Stockholm University, Alba Nova University Center, SE-106 91 Stockholm (Sweden); Institute for Physics, St. Petersburg University, Uljanovskaya 1, St. Petersburg 198904 (Russian Federation); Institute for Theoretical Atomic and Molecular Physics at Harvard University and Smithsonian Astrophysical Observatory, 60 Garden Street, MS 14 Cambridge, Massachusetts 02138 (United States); Yarevsky, Evgeny [Institute for Physics, St. Petersburg University, Uljanovskaya 1, St. Petersburg 198904 (Russian Federation); International Solvay Institutes for Physics and Chemistry, Case Postale 231, Campus Plaine ULB Boulevard du Triomphe, Brussels 1050 (Belgium)

2003-06-01T23:59:59.000Z

76

E-Print Network 3.0 - advanced finite element Sample Search Results  

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

Mathematics 17 ScienceTheoretical Experimental Summary: Adv. anal. and comp. of turbomachinery Finite Element Methods Architecture: Topics... Brain Computer...

77

Application of Mass Lumped Higher Order Finite Elements  

SciTech Connect (OSTI)

There are many interesting phenomena in extended-MHD such as anisotropic transport, mhd, 2-fluid effects stellarator and hot particles. Any one of them challenges numerical analysts, and researchers are seeking for higher order methods, such as higher order finite difference, higher order finite elements and hp/spectral elements. It is true that these methods give more accurate solution than their linear counterparts. However, numerically they are prohibitively expensive. Here we give a successful solution of this conflict by applying mass lumped higher order finite elements. This type of elements not only keep second/third order accuracy but also scale closely to linear elements by doing mass lumping. This is especially true for second order lump elements. Full M3D and anisotropic transport models are studied.

Chen, J.; Strauss, H. R.; Jardin, S. C.; Park, W.; Sugiyama, L. E.; Fu., G.; Breslau, J.

2005-11-01T23:59:59.000Z

78

adaptive finite element: Topics by E-print Network  

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

properties and performance of the adaptive finite element approach to the design of nano-photonic components. Central issues are the construction of vectorial finite elements...

79

adaptive finite elements: Topics by E-print Network  

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

properties and performance of the adaptive finite element approach to the design of nano-photonic components. Central issues are the construction of vectorial finite elements...

80

Phase Reduction Models for Improving the Accuracy of the Finite Element Solution of  

E-Print Network [OSTI]

, acoustic scattering, short-wave problem, finite element method, pollution, accuracy, On-Surface Radiation in view of a numerical finite element solution. It is well-known that pollution error causes inaccuracies the pollution error in the finite element solution of time-harmonic scattering problems. The pollution error

Boyer, Edmond

Note: This page contains sample records for the topic "finite element method" 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

Quadrilateral/hexahedral finite element mesh coarsening  

DOE Patents [OSTI]

A technique for coarsening a finite element mesh ("FEM") is described. This technique includes identifying a coarsening region within the FEM to be coarsened. Perimeter chords running along perimeter boundaries of the coarsening region are identified. The perimeter chords are redirected to create an adaptive chord separating the coarsening region from a remainder of the FEM. The adaptive chord runs through mesh elements residing along the perimeter boundaries of the coarsening region. The adaptive chord is then extracted to coarsen the FEM.

Staten, Matthew L; Dewey, Mark W; Scott, Michael A; Benzley, Steven E

2012-10-16T23:59:59.000Z

82

A New Parallel Domain Decomposition Method for the Adaptive Finite Element Solution of Elliptic Partial Di erential Equations  

E-Print Network [OSTI]

Partial Di#11;erential Equations Randolph E. Bank #3; and Peter K. Jimack y Abstract We present a new domain decomposition algorithm for the parallel #12;nite element solution of elliptic partial di#11 to be utilized in a well load-balanced manner. Finally, numerical evidence is presented which suggests

Bank, Randolph E.

83

A Mixed Finite Element Approximation for Compressible Flow of Contamination from Nuclear  

E-Print Network [OSTI]

A Mixed Finite Element Approximation for Compressible Flow of Contamination from Nuclear Waste in Porous Media S. H. CHOU AND Q. LI Abstract A compressible nuclear waste disposal contamination in porous of this system using a finite element method for the brine, radionuclides, and heat combined with a mixed finite

Chou, So-Hsiang

84

Component mode synthesis methods applied to 3D heterogeneous core calculations, using the mixed dual finite element solver MINOS  

SciTech Connect (OSTI)

This paper describes a new technique for determining the pin power in heterogeneous core calculations. It is based on a domain decomposition with overlapping sub-domains and a component mode synthesis technique for the global flux determination. Local basis functions are used to span a discrete space that allows fundamental global mode approximation through a Galerkin technique. Two approaches are given to obtain these local basis functions: in the first one (Component Mode Synthesis method), the first few spatial eigenfunctions are computed on each sub-domain, using periodic boundary conditions. In the second one (Factorized Component Mode Synthesis method), only the fundamental mode is computed, and we use a factorization principle for the flux in order to replace the higher order Eigenmodes. These different local spatial functions are extended to the global domain by defining them as zero outside the sub-domain. These methods are well-fitted for heterogeneous core calculations because the spatial interface modes are taken into account in the domain decomposition. Although these methods could be applied to higher order angular approximations - particularly easily to a SPN approximation - the numerical results we provide are obtained using a diffusion model. We show the methods' accuracy for reactor cores loaded with UOX and MOX assemblies, for which standard reconstruction techniques are known to perform poorly. Furthermore, we show that our methods are highly and easily parallelizable. (authors)

Guerin, P.; Baudron, A. M.; Lautard, J. J. [Commissariat a l'Energie Atomique, DEN/DANS/DM2S/SERMA/LENR, CEA Saclay, 91191 Gif sur Yvette (France)

2006-07-01T23:59:59.000Z

85

A finite element method with mesh adaptivity for computing vortex states in fast-rotating Bose-Einstein condensates  

E-Print Network [OSTI]

-Einstein condensates Ionut Danaila,a,b , Fr´ed´eric Hechta,b aUPMC Univ Paris 06, UMR 7598, Laboratoire Jacques Abstract Numerical computations of stationary states of fast-rotating Bose-Einstein condensates require-Einstein condensate, vortex, Sobolev gradient, descent method. 1. Introduction Recent research efforts in the field

Boyer, Edmond

86

A finite element method with mesh adaptivity for computing vortex states in fastrotating BoseEinstein condensates  

E-Print Network [OSTI]

­Einstein condensates Ionut Danaila #,a,b , Fr??ed??eric Hecht a,b a UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques Abstract Numerical computations of stationary states of fast­rotating Bose­Einstein condensates require­Einstein condensate, vortex, Sobolev gradient, descent method. 1. Introduction Recent research e#orts in the field

Recanati, Catherine

87

Least-squares variational principles and the finite element method: theory, formulations, and models for solid and fluid mechanics  

E-Print Network [OSTI]

of the weak form Galerkin procedure to problems whose solutions can be characterized as global minimizers results in global minimiza- tion of quadratic functionals, such is the case for linear elasticity problems; see [93]. In this case, given a conforming... and the success of the method for linear elasticity problems led to early attempts to extend weak form Galerkin formulations beyond problems whose solutions could be characterized as unconstrained global minimizers. For example, problems of the saddle-point type...

Pontaza, Juan Pablo

2004-09-30T23:59:59.000Z

88

Impeller deflection and modal finite element analysis.  

SciTech Connect (OSTI)

Deflections of an impeller due to centripetal forces are calculated using finite element analysis. The lateral, or out of plane, deflections are an important design consideration for this particular impeller because it incorporates an air bearing with critical gap tolerances. The target gap distance is approximately 10 microns at a rotational velocity of 2500 rpm. The centripetal forces acting on the impeller cause it deflect in a concave fashion, decreasing the initial gap distance as a function of radial position. This deflection is characterized for a previous and updated impeller design for comparative purposes. The impact of design options such as material selection, geometry dimensions, and operating rotational velocity are also explored, followed by a sensitivity study with these parameters bounded by specific design values. A modal analysis is also performed to calculate the impeller's natural frequencies which are desired to be avoided during operation. The finite element modeling techniques continue to be exercised by the impeller design team to address specific questions and evaluate conceptual designs, some of which are included in the Appendix.

Spencer, Nathan A.

2013-10-01T23:59:59.000Z

89

A NONCONFORMING FINITE ELEMENT METHOD  

E-Print Network [OSTI]

. Karakashiany and Wadi N. Jureidiniz Abstract. Approximations to solutions of the inhomogeneous boundary value

Karakashian, Ohannes

90

A finite element model for transient thermal/structural analysis of large composite space structures  

E-Print Network [OSTI]

on approximate 6 analysis techniques based on finite elements has begun. Such techniques as reduced basis techniques and generalized transform methods offer hope of solving the finite element 8 equations more efficiently. An integrated thermal/structural... integrated analysis codes. However, Mahaney, Thornton, and Dechaumphai have identified require 5 ments for such thermal/structural programs. They concluded that such analysis methods should have the following five characteristics. First, a common finite...

Lutz, James Delmar

2012-06-07T23:59:59.000Z

91

Finite element analysis of controlled laser coagulation experiments  

E-Print Network [OSTI]

, for being my best friend. ABSTRACT TABLE OF CONTENTS Page nt DEDICATION. ACKNOWLEDGMENTS . . TABLE OF CONTENTS. . LIST OF TABLES. LIST OF FIGURES CHAPTER I INTRODUCTION. II THEORETICAL BACKGROUND. 2. 1 The heat diffusion equation 2. 2 How... is the heat generated? 2. 3 Boundary conditions 2. 4 Temperature control 2. 5 Coagulation and thermal damage in biological tissues. . . III METHODOLOGY 3. 1 The finite-element method 3. 2 Element set-up of gel-tissue sample 3. 3 Input variables 3. 4...

Tolat, Nimish Prabodh

1997-01-01T23:59:59.000Z

92

A mixed finite-element scheme of a semiconductor energy-transport model  

E-Print Network [OSTI]

A mixed finite-element scheme of a semiconductor energy-transport model using dual entropy variables Stephan Gadau, Ansgar J¨ungel, and Paola Pietra Abstract. One-dimensional stationary energy employing a mixed-hybrid finite- element method which has the advantage to fulfill current conser- vation

Hanke-Bourgeois, Martin

93

Implementation of B-splines in a Conventional Finite Element Framework  

E-Print Network [OSTI]

The use of B-spline interpolation functions in the finite element method (FEM) is not a new subject. B-splines have been utilized in finite elements for many reasons. One reason is the higher continuity of derivatives and smoothness of B...

Owens, Brian C.

2010-01-16T23:59:59.000Z

94

CharacteristicGalerkin and Mixed Finite Element Approximation of Contamination by Compressible  

E-Print Network [OSTI]

Characteristic­Galerkin and Mixed Finite Element Approximation of Contamination by Compressible­disposal contamination in porous media is modeled by a coupled system of partial differential equations for the brine, radionuclides, and heat and by a mixed finite element method for the pressure and velocity

Chou, So-Hsiang

95

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION  

E-Print Network [OSTI]

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION R. M. MCM~EKING and J elastic-plastic flow.The method is based on Hill's variational principle for incremental deformations in a manner which allows any conventions finite element program, for "small strain" elastic-plastic analysis

96

A ThreeDimensional Finite Element Simulation for Transport of Nuclear Waste Contamination in Porous Media  

E-Print Network [OSTI]

A Three­Dimensional Finite Element Simulation for Transport of Nuclear Waste Contamination of South Carolina, Columbia, South Carolina ABSTRACT: Model equations for transport of nuclear­waste based up on the inherent physics. A three­dimensional finite element method for nuclear waste

Ewing, Richard E.

97

HYDRA, A finite element computational fluid dynamics code: User manual  

SciTech Connect (OSTI)

HYDRA is a finite element code which has been developed specifically to attack the class of transient, incompressible, viscous, computational fluid dynamics problems which are predominant in the world which surrounds us. The goal for HYDRA has been to achieve high performance across a spectrum of supercomputer architectures without sacrificing any of the aspects of the finite element method which make it so flexible and permit application to a broad class of problems. As supercomputer algorithms evolve, the continuing development of HYDRA will strive to achieve optimal mappings of the most advanced flow solution algorithms onto supercomputer architectures. HYDRA has drawn upon the many years of finite element expertise constituted by DYNA3D and NIKE3D Certain key architectural ideas from both DYNA3D and NIKE3D have been adopted and further improved to fit the advanced dynamic memory management and data structures implemented in HYDRA. The philosophy for HYDRA is to focus on mapping flow algorithms to computer architectures to try and achieve a high level of performance, rather than just performing a port.

Christon, M.A.

1995-06-01T23:59:59.000Z

98

Energy conserving Anisotropic Anhysteretic Magnetic Modelling for Finite Element Analysis  

E-Print Network [OSTI]

To model ferromagnetic material in finite element analysis a correct description of the constitutive relationship (BH-law) must be found from measured data. This article proposes to use the energy density function as a centrepiece. Using this function, which turns out to be a convex function of the flux density, guarantees energy conservative modelling. The magnetic field strength can be seen as a derivative with respect to the flux density. Especially for anisotropic materials (from lamination and/or grain orientation) this method has advantages. Strictly speaking this method is only valid for anhysteretic and thermodynamically stable material.

Jens Krause

2012-12-20T23:59:59.000Z

99

Parallel Finite Element Simulation of Tracer Injection in Oil Reservoirs  

E-Print Network [OSTI]

Parallel Finite Element Simulation of Tracer Injection in Oil Reservoirs Alvaro L.G.A. Coutinho In this work, parallel finite element techniques for the simulation of tracer injection in oil reservoirs. Supercomputers have made it possible to consider global reservoir effects which can not be represented using

Coutinho, Alvaro L. G. A.

100

The representation of boundary currents in a finite element shallow water model  

E-Print Network [OSTI]

We evaluate the influence of local resolution, eddy viscosity, coastline structure, and boundary conditions on the numerical representation of boundary currents in a finite element shallow-water model. The use of finite element discretization methods offers a higher flexibility compared to finite difference and finite volume methods, that are mainly used in previous publications. This is true for the geometry of the coast lines and for the realization of boundary conditions. For our investigations we simulate steady separation of western boundary currents from idealized and realistic coast lines. The use of grid refinement allows a detailed investigation of boundary separation at reasonable numerical cost.

Dben, Peter D

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

B-spline finite elements for plane elasticity problems  

E-Print Network [OSTI]

. The k-refinement is reported to be much more efficient and robust than the standard h or p- refinement used in the conventional FEM models. Besides the use of B-spline functions for structural problems, they have been used in some other fields as well... and convergence behavior. The paper reports a reduction in the numerical cost using B-spline FEM. The use of the B-spline finite element method for the thermistor problem [29,30] and for a numerical solution of Burger?s equation[31- 33] has been successfully...

Aggarwal, Bhavya

2007-04-25T23:59:59.000Z

102

Finite Element Modelling and Molecular Dynamic Simulations of Carbon nanotubes/ Polymer Composites  

E-Print Network [OSTI]

Modeling of single-walled carbon nanotubes, multi-walled nanotubes and nanotube reinforced polymer composites using both the Finite Element method and the Molecular Dynamic simulation technique is presented. Nanotubes subjected to mechanical loading...

Gaddamanugu, Dhatri

2010-07-14T23:59:59.000Z

103

Finite element decomposition and grid generation for brain modeling and visualization  

E-Print Network [OSTI]

Numerical grid generation is used to provide a framework for brain and neuron visualization. Smoothing spline surfaces are fit to contour data to generate 3D solid model reconstruction of brain tissues. Finite element methods are then used...

Batte, David Allan

1997-01-01T23:59:59.000Z

104

Finite Element Analysis of Ballistic Penetration of Plain Weave Twaron CT709 Fabrics: A Parametric Study  

E-Print Network [OSTI]

The ballistic impact of Twaron CT709 plain weave fabrics is studied using an explicit finite element method. Many existing approximations pertaining to woven fabrics cannot adequately represent strain rate-dependent behavior exhibited by the Twaron...

Gogineni, Sireesha

2011-10-21T23:59:59.000Z

105

3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)  

E-Print Network [OSTI]

3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)

106

Transactions of NAMRI/SME FINITE ELEMENT SIMULATION OF  

E-Print Network [OSTI]

Transactions of NAMRI/SME FINITE ELEMENT SIMULATION OF Ti-6Al-4V ALLOY Turul Manufacturing #12;Transactions of NAMRI/SME 50 Volume 38, 2010 excessive heat generation. Usually above 120 m

Ozel, Tugrul

107

A frequency domain finite element model for tidal circulation  

E-Print Network [OSTI]

A highly efficient finite element model has been developed for the numerical prediction of depth average circulation within small scale embayments which are often characterized by irregular boundaries and bottom topography.

Westerink, Joannes J.

1985-01-01T23:59:59.000Z

108

JAC3D -- A three-dimensional finite element computer program for the nonlinear quasi-static response of solids with the conjugate gradient method; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

JAC3D is a three-dimensional finite element program designed to solve quasi-static nonlinear mechanics problems. A set of continuum equations describes the nonlinear mechanics involving large rotation and strain. A nonlinear conjugate gradient method is used to solve the equation. The method is implemented in a three-dimensional setting with various methods for accelerating convergence. Sliding interface logic is also implemented. An eight-node Lagrangian uniform strain element is used with hourglass stiffness to control the zero-energy modes. This report documents the elastic and isothermal elastic-plastic material model. Other material models, documented elsewhere, are also available. The program is vectorized for efficient performance on Cray computers. Sample problems described are the bending of a thin beam, the rotation of a unit cube, and the pressurization and thermal loading of a hollow sphere.

Biffle, J.H.

1993-02-01T23:59:59.000Z

109

JAC2D: A two-dimensional finite element computer program for the nonlinear quasi-static response of solids with the conjugate gradient method; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

JAC2D is a two-dimensional finite element program designed to solve quasi-static nonlinear mechanics problems. A set of continuum equations describes the nonlinear mechanics involving large rotation and strain. A nonlinear conjugate gradient method is used to solve the equations. The method is implemented in a two-dimensional setting with various methods for accelerating convergence. Sliding interface logic is also implemented. A four-node Lagrangian uniform strain element is used with hourglass stiffness to control the zero-energy modes. This report documents the elastic and isothermal elastic/plastic material model. Other material models, documented elsewhere, are also available. The program is vectorized for efficient performance on Cray computers. Sample problems described are the bending of a thin beam, the rotation of a unit cube, and the pressurization and thermal loading of a hollow sphere.

Biffle, J.H.; Blanford, M.L.

1994-05-01T23:59:59.000Z

110

Accelerated finite element elastodynamic simulations using the GPU  

SciTech Connect (OSTI)

An approach is developed to perform explicit time domain finite element simulations of elastodynamic problems on the graphical processing unit, using Nvidia's CUDA. Of critical importance for this problem is the arrangement of nodes in memory, allowing data to be loaded efficiently and minimising communication between the independently executed blocks of threads. The initial stage of memory arrangement is partitioning the mesh; both a well established greedy partitioner and a new, more efficient aligned partitioner are investigated. A method is then developed to efficiently arrange the memory within each partition. The software is applied to three models from the fields of non-destructive testing, vibrations and geophysics, demonstrating a memory bandwidth of very close to the card's maximum, reflecting the bandwidth-limited nature of the algorithm. Comparison with Abaqus, a widely used commercial CPU equivalent, validated the accuracy of the results and demonstrated a speed improvement of around two orders of magnitude. A software package, Pogo, incorporating these developments, is released open source, downloadable from (http://www.pogo-fea.com/) to benefit the community. -- Highlights: A novel memory arrangement approach is discussed for finite elements on the GPU. The mesh is partitioned then nodes are arranged efficiently within each partition. Models from ultrasonics, vibrations and geophysics are run. The code is significantly faster than an equivalent commercial CPU package. Pogo, the new software package, is released open source.

Huthwaite, Peter, E-mail: p.huthwaite@imperial.ac.uk

2014-01-15T23:59:59.000Z

111

E-Print Network 3.0 - art finite element Sample Search Results  

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

system. We generated finite element models of the Boeing 767 and of the top 20 stories of the North Tower... elements. The finite ... Source: Irfanoglu, Ayhan - School of...

112

Surface photovoltage measurements and finite element modeling of SAW devices.  

SciTech Connect (OSTI)

Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

Donnelly, Christine

2012-03-01T23:59:59.000Z

113

Omega3P: A Parallel Finite-Element Eigenmode Analysis Code for Accelerator Cavities  

SciTech Connect (OSTI)

Omega3P is a parallel eigenmode calculation code for accelerator cavities in frequency domain analysis using finite-element methods. In this report, we will present detailed finite-element formulations and resulting eigenvalue problems for lossless cavities, cavities with lossy materials, cavities with imperfectly conducting surfaces, and cavities with waveguide coupling. We will discuss the parallel algorithms for solving those eigenvalue problems and demonstrate modeling of accelerator cavities through different examples.

Lee, Lie-Quan; Li, Zenghai; Ng, Cho; Ko, Kwok; /SLAC

2009-03-04T23:59:59.000Z

114

A Novel Membrane Finite Element with Drilling Rotations  

E-Print Network [OSTI]

A Novel Membrane Finite Element with Drilling Rotations Reijo Kouhia 1 Abstract. A new low order interpolation is used for the drill rotation #12;eld. Both triangular and quadrilateral elements are considered of freedom. 1 INTRODUCTION In-plane rotational degrees of freedom, \\drilling de- grees of freedom

Kouhia, Reijo

115

Phase reduction models for improving the accuracy of the finite element solution of time-harmonic scattering problems I: General  

E-Print Network [OSTI]

Accepted 12 January 2009 Available online 21 January 2009 Keywords: Helmholtz equation Acoustic scattering Short-wave problem Finite element method Pollution Accuracy On-Surface Radiation Condition method a b- lems in view of a numerical finite element solution. It is well-known that pollution error causes

Antoine, Xavier - Institut de Mathématiques ?lie Cartan, Université Henri Poincaré

116

Experimental and finite element analysis of high pressure packer elements  

E-Print Network [OSTI]

Packer elements are traditionally rubber seals that can operate under specified downhole conditions and provide a seal for either a short-term, retrievable, or a long-term, permanent, completion. In this case a retrievable ...

Berger, Stephanie, 1981-

2004-01-01T23:59:59.000Z

117

A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors  

E-Print Network [OSTI]

A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors Stefan Holst #12;tting mixed #12;nite-element method is used to discretize the stationary energy. Energy-transport models describe the ow of electrons through a semi- conductor device, in uenced by di

Pietra, Paola

118

Finite element decomposition of the human neocortex  

E-Print Network [OSTI]

dividing boundary types of neuroanatomical consistency . . . . . . . . 5 1 18 Mapping a template onto the object domain. . . . ?53 FIGURE Page 19 Hierarchical division of the human brain into its anatomical parts, . . . 54 20 Decomposition of a... major gyrus into macro elements . ?. , 56 21 Different gyral shapes and their lines of symmetry. . . . 57 22 Mapping gyral line of symmetry at different levels of detail. . . . . . . . 58 23 Sectional view in a human brain atlas. , . . . 60 24...

Chow, Seeling

1998-01-01T23:59:59.000Z

119

Nonlinear Legendre Spectral Finite Elements for Wind Turbine Blade Dynamics: Preprint  

SciTech Connect (OSTI)

This paper presents a numerical implementation and examination of new wind turbine blade finite element model based on Geometrically Exact Beam Theory (GEBT) and a high-order spectral finite element method. The displacement-based GEBT is presented, which includes the coupling effects that exist in composite structures and geometric nonlinearity. Legendre spectral finite elements (LSFEs) are high-order finite elements with nodes located at the Gauss-Legendre-Lobatto points. LSFEs can be an order of magnitude more efficient that low-order finite elements for a given accuracy level. Interpolation of the three-dimensional rotation, a major technical barrier in large-deformation simulation, is discussed in the context of LSFEs. It is shown, by numerical example, that the high-order LSFEs, where weak forms are evaluated with nodal quadrature, do not suffer from a drawback that exists in low-order finite elements where the tangent-stiffness matrix is calculated at the Gauss points. Finally, the new LSFE code is implemented in the new FAST Modularization Framework for dynamic simulation of highly flexible composite-material wind turbine blades. The framework allows for fully interactive simulations of turbine blades in operating conditions. Numerical examples showing validation and LSFE performance will be provided in the final paper.

Wang, Q.; Sprague, M. A.; Jonkman, J.; Johnson, N.

2014-01-01T23:59:59.000Z

120

Diffusive mesh relaxation in ALE finite element numerical simulations  

SciTech Connect (OSTI)

The theory for a diffusive mesh relaxation algorithm is developed for use in three-dimensional Arbitary Lagrange/Eulerian (ALE) finite element simulation techniques. This mesh relaxer is derived by a variational principle for an unstructured 3D grid using finite elements, and incorporates hourglass controls in the numerical implementation. The diffusive coefficients are based on the geometric properties of the existing mesh, and are chosen so as to allow for a smooth grid that retains the general shape of the original mesh. The diffusive mesh relaxation algorithm is then applied to an ALE code system, and results from several test cases are discussed.

Dube, E.I.

1996-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Inversion of Robin coefficient by a spectral stochastic finite element approach  

SciTech Connect (OSTI)

This paper investigates a variational approach to the nonlinear stochastic inverse problem of probabilistically calibrating the Robin coefficient from boundary measurements for the steady-state heat conduction. The problem is formulated into an optimization problem, and mathematical properties relevant to its numerical computations are investigated. The spectral stochastic finite element method using polynomial chaos is utilized for the discretization of the optimization problem, and its convergence is analyzed. The nonlinear conjugate gradient method is derived for the optimization system. Numerical results for several two-dimensional problems are presented to illustrate the accuracy and efficiency of the stochastic finite element method.

Jin Bangti [Department of Mathematics, Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)], E-mail: kimbtsing@yahoo.com.cn; Zou Jun [Department of Mathematics, Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)], E-mail: zou@math.cuhk.edu.hk

2008-03-01T23:59:59.000Z

122

Implementation of surface tension with wall adhesion effects in a three-dimensional finite element model for fluid flow  

E-Print Network [OSTI]

- 1 - Implementation of surface tension with wall adhesion effects in a three-dimensional finite element modelling of surface tension. The external stress vectors associated with surface tension a drop of liquid on a plane is treated. Keywords : surface tension, finite element method, average

Boyer, Edmond

123

Inverse Finite Element Modelling and Identification of Constitutive Parameters of UHS Steel Based on Gleeble Tensile Tests at High Temperature  

E-Print Network [OSTI]

identification method - associating a direct finite element model of Gleeble tests and an optimization module1 Inverse Finite Element Modelling and Identification of Constitutive Parameters of UHS Steel Based-2 ) hc heat transfer coefficient at interface between specimen and grips (W m-2 K) hth_eff effective

Boyer, Edmond

124

Experimental validation of finite element codes for welding deformations  

E-Print Network [OSTI]

Experimental validation of finite element codes for welding deformations H. M. Aarbogha,b, , M Institute for Energy Technology, N-2027 Kjeller, Norway. Abstract A single pass Metal Inert Gas welding which numerical codes quantifying welding stresses can be validated. It includes a mov- ing heat source

Boyer, Edmond

125

Analysis of a finite element formulation for modelling phase separation  

E-Print Network [OSTI]

equation, which makes its numerical solution particularly challenging. To this end, a finite element formulation has been developed which can solve the Cahn-Hilliard equation in its primal form using C^0 basis functions. Here, analysis of a fully discrete...

Wells, G N; Garikipati, Krishna

2007-01-01T23:59:59.000Z

126

CONTINUOUSTIME FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY  

E-Print Network [OSTI]

CONTINUOUS­TIME FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY Zhangxin Chen­water system in groundwater hydrology is given. The system is written in a fractional flow formulation, i for an air­water system in groundwater hydrology, ff = a; w [1], [11], [26]: @(OEae ff s ff ) @t +r \\Delta

127

Guaranteed Verification of Finite Element Solutions of Heat Conduction  

E-Print Network [OSTI]

is invented to estimate the exact error measured in space-time C-norm for both semi-discrete and fully discrete finite element solutions to linear parabolic problem. For a fully discrete solution, a temporal error estimator is also introduced to evaluate...

Wang, Delin

2012-07-16T23:59:59.000Z

128

Dennis, Eberhart, Dulikravich & Radons FINITE ELEMENT SIMULATION OF COOLING  

E-Print Network [OSTI]

arterial supply and effectively blocks the external cooling wave from advancing to the core of the brain1 Dennis, Eberhart, Dulikravich & Radons FINITE ELEMENT SIMULATION OF COOLING OF REALISTIC 3-D Rapid cooling of the brain in the first minutes following the onset of cerebral ischemia

Dennis, Brian

129

Finite Element Discretization Strategies for the Inverse Electrocardiographic (ECG) Problem  

E-Print Network [OSTI]

Finite Element Discretization Strategies for the Inverse Electrocardiographic (ECG) Problem Dafang electrocardiographic (ECG) problems re- quires the ability to both quantify and minimize approxi- mation errors specifically for the inverse ECG prob- lem. By quantitatively analyzing the connection between the ill

Utah, University of

130

Method for detecting an element  

DOE Patents [OSTI]

A method for detecting an element is disclosed and which includes the steps of providing a gamma-ray spectrum which depicts, at least in part, a test region having boundaries, and which has a small amount of the element to be detected; providing a calculation which detects the small amount of the element to be detected; and providing a moving window and performing the calculation within the moving window, and over a range of possible window boundaries within the test region to determine the location of the optimal test region within the gamma-ray spectrum.

Blackwood, Larry G.; Reber, Edward L.; Rohde, Kenneth W.

2007-02-06T23:59:59.000Z

131

Calibration under uncertainty for finite element models of masonry monuments  

SciTech Connect (OSTI)

Historical unreinforced masonry buildings often include features such as load bearing unreinforced masonry vaults and their supporting framework of piers, fill, buttresses, and walls. The masonry vaults of such buildings are among the most vulnerable structural components and certainly among the most challenging to analyze. The versatility of finite element (FE) analyses in incorporating various constitutive laws, as well as practically all geometric configurations, has resulted in the widespread use of the FE method for the analysis of complex unreinforced masonry structures over the last three decades. However, an FE model is only as accurate as its input parameters, and there are two fundamental challenges while defining FE model input parameters: (1) material properties and (2) support conditions. The difficulties in defining these two aspects of the FE model arise from the lack of knowledge in the common engineering understanding of masonry behavior. As a result, engineers are unable to define these FE model input parameters with certainty, and, inevitably, uncertainties are introduced to the FE model.

Atamturktur, Sezer,; Hemez, Francois,; Unal, Cetin

2010-02-01T23:59:59.000Z

132

On the role of boundary conditions for CIP stabilization of higher order finite elements  

E-Print Network [OSTI]

On the role of boundary conditions for CIP stabilization of higher order finite elements Friedhelm Schieweck 13.11.2007 Abstract We investigate the Continuous Interior Penalty (CIP) stabilization method even in the limit case where the parameter of the CIP stabilization is zero, i.e., where the standard

Schieweck, Friedhelm

133

Liquefaction Mapping in Finite-Element Simulations Kirk C. Ellison, S.M.ASCE1  

E-Print Network [OSTI]

soil liquefaction based on solid mechanical theory rather than empiricism. DOI: 10.1061/ ASCE GT.1943 potentially unstable regions in granular soils at the engineering scale. Example simulations are presented-5606.0000122 CE Database subject headings: Soil liquefaction; Finite element method; Constitutive models

Andrade, Jose

134

3-D Finite Element Analyses of the Egan Cavern Field  

SciTech Connect (OSTI)

Three-dimensional finite element analyses were performed for the two gas-filled storage caverns at the Egan field, Jennings dome, Louisiana. The effects of cavern enlargement on surface subsidence, storage loss, and cavern stability were investigated. The finite element model simulated the leaching of caverns to 6 and 8 billion cubic feet (BCF) and examined their performance at various operating conditions. Operating pressures varied from 0.15 psi/ft to 0.9 psi/ft at the bottom of the lowest cemented casing. The analysis also examined the stability of the web or pillar of salt between the caverns under differential pressure loadings. The 50-year simulations were performed using JAC3D, a three dimensional finite element analysis code for nonlinear quasistatic solids. A damage criterion based on onset of dilatancy was used to evaluate cavern instability. Dilation results from the development of microfractures in salt and, hence, potential increases in permeability onset occurs well before large scale failure. The analyses predicted stable caverns throughout the 50-year period for the range of pressures investigated. Some localized salt damage was predicted near the bottom walls of the caverns if the caverns are operated at minimum pressure for long periods of time. Volumetric cavern closures over time due to creep were moderate to excessive depending on the salt creep properties and operating pressures. However, subsidence above the cavern field was small and should pose no problem, to surface facilities.

Klamerus, E.W.; Ehgartner, B.L.

1999-02-01T23:59:59.000Z

135

An evaluation of finite element models of stiffened plates subjected to impulsive loading  

E-Print Network [OSTI]

Different finite element models are evaluated for two very common structures, a cantilever beam and a stiffened plate, subjected to impulsive loading. For the cantilever beam case, the finite element models are one, two ...

Pedatzur, Omri

2004-01-01T23:59:59.000Z

136

Finite element analyses for seismic shear wall international standard problem  

SciTech Connect (OSTI)

Two identical reinforced concrete (RC) shear walls, which consist of web, flanges and massive top and bottom slabs, were tested up to ultimate failure under earthquake motions at the Nuclear Power Engineering Corporation`s (NUPEC) Tadotsu Engineering Laboratory, Japan. NUPEC provided the dynamic test results to the OECD (Organization for Economic Cooperation and Development), Nuclear Energy Agency (NEA) for use as an International Standard Problem (ISP). The shear walls were intended to be part of a typical reactor building. One of the major objectives of the Seismic Shear Wall ISP (SSWISP) was to evaluate various seismic analysis methods for concrete structures used for design and seismic margin assessment. It also offered a unique opportunity to assess the state-of-the-art in nonlinear dynamic analysis of reinforced concrete shear wall structures under severe earthquake loadings. As a participant of the SSWISP workshops, Brookhaven National Laboratory (BNL) performed finite element analyses under the sponsorship of the U.S. Nuclear Regulatory Commission (USNRC). Three types of analysis were performed, i.e., monotonic static (push-over), cyclic static and dynamic analyses. Additional monotonic static analyses were performed by two consultants, F. Vecchio of the University of Toronto (UT) and F. Filippou of the University of California at Berkeley (UCB). The analysis results by BNL and the consultants were presented during the second workshop in Yokohama, Japan in 1996. A total of 55 analyses were presented during the workshop by 30 participants from 11 different countries. The major findings on the presented analysis methods, as well as engineering insights regarding the applicability and reliability of the FEM codes are described in detail in this report. 16 refs., 60 figs., 16 tabs.

Park, Y.J.; Hofmayer, C.H.

1998-04-01T23:59:59.000Z

137

Domain decomposition for coupling finite and boundary element methods in EEG Emmanuel Olivi1, Maureen Clerc1 and Theodore Papadopoulo1  

E-Print Network [OSTI]

in the patient head. Yet, the skull anisotropy happens to be highly anisotropic, and must then be modeled.e. for the brain and the scalp). A domain decomposition (DD) framework allows to split the global system. This work presents such a coupling formulation of a 3-DD method solving iteratively a BEM for the brain

Boyer, Edmond

138

Finite Element Multi-physics Modeling for Ohmic Contact of Microswitches , D. Leray1, 2  

E-Print Network [OSTI]

Finite Element Multi-physics Modeling for Ohmic Contact of Microswitches H.Liu1, 2 , D. Leray1, 2-physics modelling of electrical contact is accomplished with the finite element commercial package ANSYSTM . Two behaviour of electrical contact with rough surface included. Keywords: multi-physics, finite element

Boyer, Edmond

139

Finite Element Modeling of the Deformation of a Thin Magnetoelastic Film Compared to a Membrane Model  

SciTech Connect (OSTI)

Recently a new class of biocompatible elastic polymers loaded with small ferrous particles (magnetoelastomer) was developed at Lawrence Livermore National Laboratory. This new material was formed as a thin film using spin casting. The deformation of this material using a magnetic field has many possible applications to microfluidics. Two methods will be used to calculate the deformation of a circular magneto-elastomeric film subjected to a magnetic field. The first method is an arbitrary Lagrangian-Eulerian (ALE) finite element method (FEM) and the second is based on nonlinear continuum electromagnetism and continuum elasticity in the membrane limit. The comparison of these two methods is used to test/validate the finite element method.

Barham, M; White, D; Steigmann, D; Rudd, R

2009-04-08T23:59:59.000Z

140

On Some Versions of the Element Agglomeration AMGe Method  

SciTech Connect (OSTI)

The present paper deals with element-based AMG methods that target linear systems of equations coming from finite element discretizations of elliptic PDEs. The individual element information (element matrices and element topology) is the main input to construct the AMG hierarchy. We study a number of variants of the spectral agglomerate element based AMG method. The core of the algorithms relies on element agglomeration utilizing the element topology (built recursively from fine to coarse levels). The actual selection of the coarse degrees of freedom (dofs) is based on solving large number of local eigenvalue problems. Additionally, we investigate strategies for adaptive AMG as well as multigrid cycles that are more expensive than the V-cycle utilizing simple interpolation matrices and nested conjugate gradient (CG) based recursive calls between the levels. The presented algorithms are illustrated with an extensive set of experiments based on a matlab implementation of the methods.

Lashuk, I; Vassilevski, P

2007-08-09T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Visualizing Higher Order Finite Elements: FY05 Yearly Report.  

SciTech Connect (OSTI)

This report contains an algorithm for decomposing higher-order finite elementsinto regions appropriate for isosurfacing and proves the conditions under which thealgorithm will terminate. Finite elements are used to create piecewise polynomialapproximants to the solution of partial differential equations for which no analyticalsolution exists. These polynomials represent fields such as pressure, stress, and mo-mentim. In the past, these polynomials have been linear in each parametric coordinate.Each polynomial coefficient must be uniquely determined by a simulation, and thesecoefficients are called degrees of freedom. When there are not enough degrees of free-dom, simulations will typically fail to produce a valid approximation to the solution.Recent work has shown that increasing the number of degrees of freedom by increas-ing the order of the polynomial approximation (instead of increasing the number offinite elements, each of which has its own set of coefficients) can allow some typesof simulations to produce a valid approximation with many fewer degrees of freedomthan increasing the number of finite elements alone. However, once the simulation hasdetermined the values of all the coefficients in a higher-order approximant, tools donot exist for visual inspection of the solution.This report focuses on a technique for the visual inspection of higher-order finiteelement simulation results based on decomposing each finite element into simplicialregions where existing visualization algorithms such as isosurfacing will work. Therequirements of the isosurfacing algorithm are enumerated and related to the placeswhere the partial derivatives of the polynomial become zero. The original isosurfacingalgorithm is then applied to each of these regions in turn.3 AcknowledgementThe authors would like to thank David Day and Louis Romero for their insight into poly-nomial system solvers and the LDRD Senior Council for the opportunity to pursue thisresearch. The authors were supported by the United States Department of Energy, Officeof Defense Programs by the Labratory Directed Research and Development Senior Coun-cil, project 90499. Sandia is a multiprogram laboratory operated by Sandia Corporation,a Lockheed-Martin Company, for the United States Department of Energy under contractDE-AC04-94-AL85000.4

Thompson, David; Pebay, Philippe Pierre

2005-11-01T23:59:59.000Z

142

Current commutator anomalies in finite-element quantum electrodynamics  

E-Print Network [OSTI]

Four-dimensional quantum electrodynamics has been formulated on a hypercubic Minkowski finite-element lattice. The equations of motion have been derived so as to preserve lattice gauge invariance and have been shown to be unitary. In addition, species doubling is avoided due to the nonlocality of the interactions. The model is used to investigate the lattice current algebra. Regularization of the current is shown to arise in a natural and nonarbitrary way. The commutators of the lattice current are calculated and shown to have the expected qualitative behavior. These lattice results are compared to various continuum calculations. (Five figures available from author.)

Dean F. Miller

1993-12-20T23:59:59.000Z

143

Fracture and Fragmentation of Simplicial Finite Elements Meshes using Graphs  

SciTech Connect (OSTI)

An approach for the topological representation of simplicial finite element meshes as graphs is presented. It is shown that by using a graph, the topological changes induced by fracture reduce to a few, local kernel operations. The performance of the graph representation is demonstrated and analyzed, using as reference the 3D fracture algorithm by Pandolfi and Ortiz [22]. It is shown that the graph representation initializes in O(N{sub E}{sup 1.1}) time and fractures in O(N{sub I}{sup 1.0}) time, while the reference implementation requires O(N{sub E}{sup 2.1}) time to initialize and O(N{sub I}{sup 1.9}) time to fracture, where NE is the number of elements in the mesh and N{sub I} is the number of interfaces to fracture.

Mota, A; Knap, J; Ortiz, M

2006-10-18T23:59:59.000Z

144

AN ADAPTIVE FINITE ELEMENT METHOD FOR THE ...  

E-Print Network [OSTI]

adaptive strategy is established for the diffraction grating problem, such that ...... applications in optical filters and guided mode resonance devices. the...

2014-05-20T23:59:59.000Z

145

Programing the Finite Element Method with Matlab  

E-Print Network [OSTI]

Oct 3, 2002 ... font d denotes a vector or matrix which is of dimension of the ... following Matlab code which sets the row and column of a matrix A to zero.

2002-10-03T23:59:59.000Z

146

PARTIALLY PENALIZED IMMERSED FINITE ELEMENT METHODS ...  

E-Print Network [OSTI]

v+(x, y) = c+. 1 + c+. 2 x + c+. 3 y, if (x, y) ? K+, which satisfies the following jump conditions [38]: v?(D) = v+(D), v?(E) = v+(E), ??. ?v?. ?nDE. = ?+ ?v+. ?nDE.

2014-03-14T23:59:59.000Z

147

A NONCONFORMING MIXED FINITE ELEMENT METHOD FOR ...  

E-Print Network [OSTI]

tric conductivity from measurements of natural electric and magnetic fields on the ... have been widely used in electrical engineering applications, with the best-...

1910-10-30T23:59:59.000Z

148

Control-volume mixed finite element methods  

E-Print Network [OSTI]

Z. Cai a, J.E. Jones b, S.F. McCormick c and T.F. Russell d a Center for ...... (59). The Darcy equations for vertical faces normal to x-fluxes and y-fluxes would be.

1998-01-23T23:59:59.000Z

149

Finite Element Analysis of Warpage in Laminated Aluminium Alloy Plates for Machining of Primary Aeronautic Parts  

SciTech Connect (OSTI)

The aim of this paper consists in presenting a method of simulating the warpage in 7xxx series aluminium alloy plates. To perform this simulation finite element software MSC.Patran and MSC.Marc were used. Another result of this analysis will be the influence on material residual stresses induced on the raw material during the rolling process upon the warpage of primary aeronautic parts, fabricated through machining (milling) at Embraer. The method used to determinate the aluminium plate residual stress was Layer Removal Test. The numerical algorithm Modified Flavenot Method was used to convert layer removal and beam deflection in stress level. With such information about the level and profile of residual stresses become possible, during the step that anticipate the manufacturing to incorporate these values in the finite-element approach for modelling warpage parts. Based on that warpage parameter surely the products are manufactured with low relative vulnerability propitiating competitiveness and price.

Reis, A. C.; Moreira Filho, L. A. [ITA - Aeronautic Technological Institute, IEM, Praca Mal. Eduardo Gomes, 50 - Vila das Acacias - S. J. Campos, CEP 1228-900 (Brazil); Menezes, M. A. [ITA - Aeronautic Technological Institute, IEM, Praca Mal. Eduardo Gomes, 50 - Vila das Acacias - S. J. Campos, CEP 1228-900 (Brazil); UNESP - Sao Paulo State University, Ilha Solteira Engineering Faculty, DEM, Av. Brasil, 56 - Centro - Ilha Solteira - SP, CEP 15385-000 (Brazil)

2007-04-07T23:59:59.000Z

150

Fidelity of a Finite Element Model for Longitudinal Wave Propagation in Thick Cylindrical Wave Guides  

SciTech Connect (OSTI)

The ability to model wave propagation in circular cylindrical bars of finite length numerically or analytically has many applications. In this thesis the capability of an explicit finite element method to model longitudinal waves in cylindrical rods with circular cross-sections is explored. Dispersion curves for the first four modes are compared to the analytical solution to determine the accuracy of various element sizes and time steps. Values for the time step and element size are determined that retain accuracy while minimizing computational time. The modeling parameters are validated by calculating a signal propagated with a broadband input force. Limitations on the applicability are considered along with modeling parameters that should be applicable to more general geometries.

Puckett, A.D.

2000-09-01T23:59:59.000Z

151

A Finite Element Model for Simulation of Carbon Dioxide Sequestration  

SciTech Connect (OSTI)

We present a hydro-mechanical model, followed by stress, deformation, and shear-slip failure analysis for geological sequestration of carbon dioxide (CO2). The model considers the poroelastic effects by taking into account of the two-way coupling between the geomechanical response and the fluid flow process. Analytical solutions for pressure and deformation fields were derived for a typical geological sequestration scenario in our previous work. A finite element approach is introduced here for numerically solving the hydro-mechanical model with arbitrary boundary conditions. The numerical approach was built on an open-source finite element code Elmer, and results were compared to the analytical solutions. The shear-slip failure analysis was presented based on the numerical results, where the potential failure zone is identified. Information is relevant to the prediction of the maximum sustainable injection rate or pressure. The effects of caprock permeability on the fluid pressure, deformation, stress, and the shear-slip failure zone were also quantitatively studied. It was shown that a larger permeability in caprock and base rock leads to a larger uplift but a smaller shear-slip failure zone.

Bao, Jie; Xu, Zhijie; Fang, Yilin

2013-11-02T23:59:59.000Z

152

Large-Scale Parallel Finite Element Analysis of the Stress Singular Problems  

SciTech Connect (OSTI)

In this paper, the convergence behavior of large-scale parallel finite element method for the stress singular problems was investigated. The convergence behavior of iterative solvers depends on the efficiency of the pre-conditioners. However, efficiency of pre-conditioners may be influenced by the domain decomposition that is necessary for parallel FEM. In this study the following results were obtained: Conjugate gradient method without preconditioning and the diagonal scaling preconditioned conjugate gradient method were not influenced by the domain decomposition as expected. symmetric successive over relaxation method preconditioned conjugate gradient method converged 6% faster as maximum if the stress singular area was contained in one sub-domain. (authors)

Noriyuki Kushida; Hiroshi Okuda; Genki Yagawa [University of Tokyo (Japan)

2002-07-01T23:59:59.000Z

153

THE FINITE GROUPS WITH NO REAL p-ELEMENTS SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO  

E-Print Network [OSTI]

THE FINITE GROUPS WITH NO REAL p-ELEMENTS SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO Abstract/Generalitat Valenciana. 1 #12;2 SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO Theorem D. Let G be a finite group

Malle, Gunter

154

TOPAZ3D. 3-D Finite Element Heat Transfer  

SciTech Connect (OSTI)

TOPAZ3D is a three-dimensional implicit finite element computer code for heat transfer analysis. TOPAZ3D can be used to solve for the steady-state or transient temperature field on three-dimensional geometries. Material properties may be temperature-dependent and either isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions can be specified including temperature, flux, convection, and radiation. By implementing the user subroutine feature, users can model chemical reaction kinetics and allow for any type of functional representation of boundary conditions and internal heat generation. TOPAZ3D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in the material surrounding the enclosure. Additional features include thermal contact resistance across an interface, bulk fluids, phase change, and energy balances.

Shapiro, A.B. [Lawrence Livermore National Lab., CA (United States)

1992-02-24T23:59:59.000Z

155

FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE  

SciTech Connect (OSTI)

The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.

Jordan, J.

2010-06-02T23:59:59.000Z

156

Finite element analyses of a linear-accelerator electron gun  

SciTech Connect (OSTI)

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000?C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wasy, A. [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of)] [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan)] [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2014-02-15T23:59:59.000Z

157

Numerical solution of 2-D nonlinear inverse heat conduction problems using finite-element techniques  

SciTech Connect (OSTI)

A general method is presented for solving different classes of nonlinear inverse heat conduction problems (IHCP) for two-dimensional, arbitrarily shaped bodies. It is based on the systematic use of a finite-element library. It is shown that, following this approach, the conjugate gradient method can be easily implemented. The method offers a very wide field of practical applications in inverse thermal analysis, while reducing very significantly the amount of work which remains specific for each particular IHPC. Two numerical experiments illustrate the influence of data errors and the iterative regularization principle.

Khachfe, R.A.; Jarny, Y.

2000-02-01T23:59:59.000Z

158

Solar Electric Generating System II finite element analysis  

SciTech Connect (OSTI)

On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a low order nonlinear dynamic model containing only 40 degrees of freedom. This model was then used as a design tool to estimate joint dynamics. Using this design tool, joint configurations were modified, and an acceptable joint redesign determined. The results of this analysis showed that the implementation of metal stops welded to support shafts for the purpose of preventing joint separation is a suitable joint redesign. Moreover, it was found that, for quakes of Landers` magnitude, mirror breakage due to enhanced vibration in the trough assembly is unlikely.

Dohner, J.L.; Anderson, J.R.

1994-04-01T23:59:59.000Z

159

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation  

E-Print Network [OSTI]

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tube­Nusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem

Wei, Dongming

160

Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems  

E-Print Network [OSTI]

Finite element simulations of hydrodynamic trapping in microfluidic particle- trap array systems;Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems Xiaoxiao) simulation is a powerful tool in the design and implementation of microfluidic systems, especially

Nehorai, Arye

Note: This page contains sample records for the topic "finite element method" 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

Finite element meshing approached as a global minimization process  

SciTech Connect (OSTI)

The ability to generate a suitable finite element mesh in an automatic fashion is becoming the key to being able to automate the entire engineering analysis process. However, placing an all-hexahedron mesh in a general three-dimensional body continues to be an elusive goal. The approach investigated in this research is fundamentally different from any other that is known of by the authors. A physical analogy viewpoint is used to formulate the actual meshing problem which constructs a global mathematical description of the problem. The analogy used was that of minimizing the electrical potential of a system charged particles within a charged domain. The particles in the presented analogy represent duals to mesh elements (i.e., quads or hexes). Particle movement is governed by a mathematical functional which accounts for inter-particles repulsive, attractive and alignment forces. This functional is minimized to find the optimal location and orientation of each particle. After the particles are connected a mesh can be easily resolved. The mathematical description for this problem is as easy to formulate in three-dimensions as it is in two- or one-dimensions. The meshing algorithm was developed within CoMeT. It can solve the two-dimensional meshing problem for convex and concave geometries in a purely automated fashion. Investigation of the robustness of the technique has shown a success rate of approximately 99% for the two-dimensional geometries tested. Run times to mesh a 100 element complex geometry were typically in the 10 minute range. Efficiency of the technique is still an issue that needs to be addressed. Performance is an issue that is critical for most engineers generating meshes. It was not for this project. The primary focus of this work was to investigate and evaluate a meshing algorithm/philosophy with efficiency issues being secondary. The algorithm was also extended to mesh three-dimensional geometries. Unfortunately, only simple geometries were tested before this project ended. The primary complexity in the extension was in the connectivity problem formulation. Defining all of the interparticle interactions that occur in three-dimensions and expressing them in mathematical relationships is very difficult.

WITKOWSKI,WALTER R.; JUNG,JOSEPH; DOHRMANN,CLARK R.; LEUNG,VITUS J.

2000-03-01T23:59:59.000Z

162

A finite element approach to study cavitation instabilities in non-linear elastic solids under general loading conditions  

E-Print Network [OSTI]

A finite element approach to study cavitation instabilities in non-linear elastic solids under a b s t r a c t This paper proposes an effective numerical method to study cavitation instabilities a single infinitesimal defect at its center. The occurrence of cavitation is identified as the event when

Lopez-Pamies, Oscar

163

Simulation of dynamic fracture using peridynamics, finite element modeling, and contact.  

SciTech Connect (OSTI)

Peridynamics is a nonlocal extension of classical solid mechanics that allows for the modeling of bodies in which discontinuities occur spontaneously. Because the peridynamic expression for the balance of linear momentum does not contain spatial derivatives and is instead based on an integral equation, it is well suited for modeling phenomena involving spatial discontinuities such as crack formation and fracture. In this study, both peridynamics and classical finite element analysis are applied to simulate material response under dynamic blast loading conditions. A combined approach is utilized in which the portion of the simulation modeled with peridynamics interacts with the finite element portion of the model via a contact algorithm. The peridynamic portion of the analysis utilizes an elastic-plastic constitutive model with linear hardening. The peridynamic interface to the constitutive model is based on the calculation of an approximate deformation gradient, requiring the suppression of possible zero-energy modes. The classical finite element portion of the model utilizes a Johnson-Cook constitutive model. Simulation results are validated by direct comparison to expanding tube experiments. The coupled modeling approach successfully captures material response at the surface of the tube and the emerging fracture pattern. The coupling of peridynamics and finite element analysis via a contact algorithm has been shown to be a viable means for simulating material fracture in a high-velocity impact experiment. A combined peridynamics/finite element approach was applied to model an expanding tube experiment performed by Vogler, et al., in which loading on the tube is a result of Lexan slugs impacting inside the tube. The Lexan portion of the simulation was modeled with finite elements and a Johnson-Cook elastic-plastic material model in conjunction with an equation-of-state law. The steel tube portion of the simulation was modeled with peridynamics, an elastic-plastic material model, and a critical stretch bond damage model. The application of peridynamics to the tube portion of the model allowed the capture of the formation of cracks and eventual fragmentation of the tube. The simulation results yielded good agreement with the experimental results published by Vogler, et al., for the velocity and displacement profiles on the surface of the tube and the resulting fragment distribution. Numerical difficulties were encountered that required removal of hexahedron elements from the Lexan portion of the model over the course of the simulation. The significant number of inverted and nearly-inverted elements appearing over the course of the simulation is believed to be a result of irregularities in the contact between the Lexan and AerMet portions of the model, and was likely exacerbated by the ultra-high strength of the AerMet tube. Future simulations are planned in which the Lexan portion of the simulation is modeled with peridynamics, or with an alternative method such as smoothed particle hydrodynamics, with the goal of reducing these numerical difficulties.

Littlewood, David John

2010-11-01T23:59:59.000Z

164

Development of a finite element model of decompressive craniectomy  

E-Print Network [OSTI]

of high strains were comparatively small. Mesh. Axi-symmetric quadratic elements with reduced inte- gration (Abaqus element CAX8RPH) were used in all FE models. A fine mesh was created directly under the craniectomy edge with an average element length of 0...

Fletcher, Tim L.; Kolias, Angelos G.; Hutchinson, Peter J. A.; Sutcliffe, Michael P. F.

2014-07-15T23:59:59.000Z

165

Method of lightening radiation darkened optical elements  

DOE Patents [OSTI]

A method of lightening a radiation-darkened optical element in wich visible optical energy or electromagnetic radiation having a wavelength in the range of from about 2000 to about 20,000 angstroms is directed into the radiation-darkened optical element; the method may be used to lighten radiation-darkened optical element in-situ during the use of the optical element to transmit data by electronically separating the optical energy from the optical output by frequency filtering, data cooling, or interlacing the optic energy between data intervals.

Reich, Frederich R. (Richland, WA); Schwankoff, Albert R. (W. Richland, WA)

1980-01-01T23:59:59.000Z

166

A Mortar Mimetic Finite Difference Method on Non-Matching Grids  

E-Print Network [OSTI]

of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, TX 78712, U.S.A., mfw]. The methods has also been extended to locally refined meshes with hanging nodes [19], A connection between velocities in MFD methods on h2-uniform quadrilateral meshes was established. Mixed finite element (MFE

Berndt, Markus

167

Finite element analysis of blister formation in laser-induced forward transfer  

E-Print Network [OSTI]

, the large film thickness and small thermal diffusivity of the polymer minimize heat diffusion throughARTICLES Finite element analysis of blister formation in laser-induced forward transfer Nicholas T

Arnold, Craig B.

168

Finite element simulation and parameter optimization of a flexible tactile pressure sensor array  

E-Print Network [OSTI]

A finite element model was developed to optimize design of a flexible tactile sensor. The sensor consists of layers of thin-film copper and PDMS, and the model can be used to determine the effects on sensor sensitivity and ...

Lee, Shira M. (Shira Miriam)

2005-01-01T23:59:59.000Z

169

A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM*  

E-Print Network [OSTI]

.3) 0 system models the electric heating* *ial differential equation describing the electric heating of a conducting body. We prove err* *or A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM

Larsson, Stig

170

TEA - a linear frequency domain finite element model for tidal embayment analysis  

E-Print Network [OSTI]

A frequency domain (harmonic) finite element model is developed for the numerical prediction of depth average circulation within small embayments. Such embayments are often characterized by irregular boundaries and bottom ...

Westerink, Joannes J.

1984-01-01T23:59:59.000Z

171

Finite element analysis of flows in secondary settling tanks D. Kleine 1 B. D. Reddy 2  

E-Print Network [OSTI]

Finite element analysis of flows in secondary settling tanks D. Kleine 1 B. D. Reddy 2 December 7, 2003 Abstract The equations governing unsteady flows in secondary settling tanks, a component settling tanks, and against results obtained from a finite difference code based on an idealized one

Reddy, Batmanathan Dayanand "Daya"

172

A shear deformable, doubly curved finite element for the analysis of laminated composite structures  

E-Print Network [OSTI]

A SHL'AR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Submitted to the Graduate College of Texas AE-M University in partial fulfiHment of the requirement... for the degree of MASTER OF SCIENCE May 1988 Major Subject: Mechanical Engineering A SHEAR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Approved as to style and content by...

Fuehne, Joseph Patrick

2012-06-07T23:59:59.000Z

173

A three dimensional finite element code for the analysis of damage in helically wound composite cylinders  

E-Print Network [OSTI]

A THREE DIMENSIONAL FINITE ELEMENT CODE FOR THE ANALYSIS OF DAMAGE IN HELICALLY WOUND COMPOSITE CYLINDERS A Thesis MARVIiN AiNTHONY ZOCHER Submitted to the Office of Graduate Studies of Texas Ag:M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1990 Major Subject; Aerospace Engineering A THREE DIMENSIONAL FINITE ELEMENT CODE FOR THE ANALYSIS OF DAMAGE IN HELICALLY WOUND COMPOSITE CYLINDERS A Thesis by i%1ARVIN ANTHONY ZOCHER Approved...

Zocher, Marvin Anthony

2012-06-07T23:59:59.000Z

174

A finite element model for laminated composite plates with matrix cracks and delaminations  

E-Print Network [OSTI]

A FINITE ELEMENT MODEL FOR LAMINATED COMPOSITE PLATES WITH MATRIX CRACKS AND DELAMINATIONS A Thesis by KEVIN DANIEL BUIE Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of' the requirements... for the degree of MASTER OF SCIENCE December 1988 Major Subject: Aerospace Engineering A FINITE ELEMENT MODEL FOR LAMINATED COMPOSITE PLATES WITH MATRIX CRACKS AND DELAMINATIONS A Thesis by KEVIN DANIEL BUIE Approved as to style and content by: David H...

Buie, Kevin Daniel

1988-01-01T23:59:59.000Z

175

Constitutive model effects on finite element modeling of elastomer behavior in radial interference seal configurations  

E-Print Network [OSTI]

CONSTITUTIVE MODEL EFFECTS ON FINITE ELEMENT MODELING OF ELASTOMER BEHAVIOR IN RADIAL INTERFERENCE SEAL CONFIGURATIONS A Thesis by JASON R. JACKSON Subnutted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1996 Major Subject: Mechanical Engineering CONSTITUTIVE MODEL EFFECTS ON FINITE ELEMENT MODELING OF ELASTOMER BEHAVIOR IN RADIAL INTERFERENCE SEAL CONFIGURATIONS A Thesis by JASON R. JACKSON...

Jackson, Jason R.

1996-01-01T23:59:59.000Z

176

Two dimensional finite element analysis of homogenization and failure in plain weave textile composites  

E-Print Network [OSTI]

TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA Submitted to the Office of Graduate Studies of Texas ARM University In partial fulffllment... of the requirements for the degree of MASTER OF SCIENCE August 1993 Major Subject: Aerospace Engineering TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA...

Kondagunta, Veeraraghava Gopal

1993-01-01T23:59:59.000Z

177

Evaluation of new techniques for two dimensional finite element analysis of woven composites  

E-Print Network [OSTI]

EVALUATION OF NEW TECHNIQUES FOR TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF WOVEN COMPOSITES A Thesis by SITARAM CHOWDARY GUNDAPANENI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE DECEMBER 1992 Major Subject: Aerospace Engineering EVALUATION OF NEW TECHNIQUES FOR TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF WOVEN COMPOSITES A Thesis by SITARAM CHOWDARY GUNDAPANENI Approved...

Gundapaneni, Sitaram Chowdary

1992-01-01T23:59:59.000Z

178

A finite element viscous flow analysis in a radial turbine scroll  

E-Print Network [OSTI]

A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis DONALD LEE HILL JR. Submitted to the Graduate College. of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1987 Major Subject: Mechanical Engineering A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis by DONALD LEE HILL JR. Approved as to style snd content by: Dr. Erian A. Baskharone (Chairman of Conunittee) Dr. Alan B azzolo...

Hill, Donald Lee

1987-01-01T23:59:59.000Z

179

Spectral analysis method for detecting an element  

DOE Patents [OSTI]

A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

2008-02-12T23:59:59.000Z

180

Non-periodic finite-element formulation of KohnSham density functional theory  

E-Print Network [OSTI]

Non-periodic finite-element formulation of Kohn­Sham density functional theory Phanish-element formulation for Kohn­Sham density functional theory (KS-DFT). We transform the original variational problem, dislocations and crack tips using density functional theory (DFT) at reasonable computational cost by retaining

Ortiz, Michael

Note: This page contains sample records for the topic "finite element method" 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

Finite element analysis of the Arquin-designed CMU wall under a dynamic (blast) load.  

SciTech Connect (OSTI)

The Arquin Corporation designed a CMU (concrete masonry unit) wall construction and reinforcement technique that includes steel wire and polymer spacers that is intended to facilitate a faster and stronger wall construction. Since the construction method for an Arquin-designed wall is different from current wall construction practices, finite element computer analyses were performed to estimate the ability of the wall to withstand a hypothetical dynamic load, similar to that of a blast from a nearby explosion. The response of the Arquin wall was compared to the response of an idealized standard masonry wall exposed to the same dynamic load. Results from the simulations show that the Arquin wall deformed less than the idealized standard wall under such loading conditions. As part of a different effort, Sandia National Laboratories also looked at the relative static response of the Arquin wall, results that are summarized in a separate SAND Report.

Lopez, Carlos; Petti, Jason P.

2008-12-01T23:59:59.000Z

182

Comparasion of finite difference and finite element hydrodynamic models applied to the Laguna Madre Estuary, Texas  

E-Print Network [OSTI]

, and constituent fluxes. The finite difference scheme in SW=D is based on a spatial discretization of the water body as a grid of equal sized, square cers. The model includes the effects of wetting and drying, wind, inflows and return flows, flow barriers...

McArthur, Karl Edward

1996-01-01T23:59:59.000Z

183

A piecewise linear finite element discretization of the diffusion equation  

E-Print Network [OSTI]

it discretizes the diffusion equation on an arbitrary polyhedral mesh. We implemented our method in the KULL software package being developed at Lawrence Livermore National Laboratory. This code previously utilized Palmer's method as its diffusion solver, which...

Bailey, Teresa S

2006-10-30T23:59:59.000Z

184

Finite element analysis of the distortion of a crystal monochromator from synchrotron radiation thermal loading  

SciTech Connect (OSTI)

The first crystal of the Brown-Hower x-ray monochromator of the LBL-EXXON 54 pole wiggler beamline at Stanford Synchrotron Radiation Laboratory (SSRL) is subjected to intense synchrotron radiation. To provide an accurate thermal/structural analysis of the existing monochromator design, a finite element analysis (FEA) was performed. A very high and extremely localized heat flux is incident on the Si (220) crystal. The crystal, which possesses pronouncedly temperature-dependent orthotropic properties, in combination with the localized heat load, make the analysis ideally suited for finite element techniques. Characterization of the incident synchrotron radiation is discussed, followed by a review of the techniques employed in modeling the monochromator and its thermal/structural boundary conditions. The results of the finite element analysis, three-dimensional temperature distributions, surface displacements and slopes, and stresses, in the area of interest, are presented. Lastly, the effects these results have on monochromator output flux and resolution are examined.

Edwards, W.R.; Hoyer, E.H.; Thompson, A.C.

1985-10-01T23:59:59.000Z

185

COYOTE : a finite element computer program for nonlinear heat conduction problems. Part I, theoretical background.  

SciTech Connect (OSTI)

The need for the engineering analysis of systems in which the transport of thermal energy occurs primarily through a conduction process is a common situation. For all but the simplest geometries and boundary conditions, analytic solutions to heat conduction problems are unavailable, thus forcing the analyst to call upon some type of approximate numerical procedure. A wide variety of numerical packages currently exist for such applications, ranging in sophistication from the large, general purpose, commercial codes, such as COMSOL, COSMOSWorks, ABAQUS and TSS to codes written by individuals for specific problem applications. The original purpose for developing the finite element code described here, COYOTE, was to bridge the gap between the complex commercial codes and the more simplistic, individual application programs. COYOTE was designed to treat most of the standard conduction problems of interest with a user-oriented input structure and format that was easily learned and remembered. Because of its architecture, the code has also proved useful for research in numerical algorithms and development of thermal analysis capabilities. This general philosophy has been retained in the current version of the program, COYOTE, Version 5.0, though the capabilities of the code have been significantly expanded. A major change in the code is its availability on parallel computer architectures and the increase in problem complexity and size that this implies. The present document describes the theoretical and numerical background for the COYOTE program. This volume is intended as a background document for the user's manual. Potential users of COYOTE are encouraged to become familiar with the present report and the simple example analyses reported in before using the program. The theoretical and numerical background for the finite element computer program, COYOTE, is presented in detail. COYOTE is designed for the multi-dimensional analysis of nonlinear heat conduction problems. A general description of the boundary value problems treated by the program is presented. The finite element formulation and the associated numerical methods used in COYOTE are also outlined. Instructions for use of the code are documented in SAND2010-0714.

Glass, Micheal W.; Hogan, Roy E., Jr.; Gartling, David K.

2010-03-01T23:59:59.000Z

186

Visualization of high resolution, three-dimensional, nonlinear finite element analyses  

SciTech Connect (OSTI)

A two-pass surface extraction algorithm for adaptive finite element meshes is presented in the context of a visualization study for a particle impact and a turbine containment problem. The direct use of finite element data structures for the computation of external surfaces, surface normals, and derived physical quantities is discussed. An overview of the in-betweening algorithm which compensates for rigid body dynamics is presented with a brief discussion of a {open_quotes}direct-to-videodisk{close_quotes} animation strategy.

Christon, M.A.; Spelce, T.E.

1992-03-24T23:59:59.000Z

187

Iterative solutions to large sparse finite element equations  

E-Print Network [OSTI]

direct solvers. The theory behind the convergence rate relationship and storage requirements for the preconditioned conjugate gradient methods using the diagonal scaling, incomplete Cholesky decomposition and SSOR preconditioners is explained in detail...

Wang, Hongbing

1995-01-01T23:59:59.000Z

188

Finite element plate formulation including transverse shear effects for representing composite shell structures  

E-Print Network [OSTI]

For Representing Composite Shell Structures. (May 1987) Jsmil M. Hamdallah, B. S. , University of Toledo Chairman of Advisory Committee: Dr. John J. Engblom A finite element formulation for the analysis of thin to moderately thick lam- inated composite shell... in an analysis if delamination is to be avoided. The results obtained in this research confirm the potential use of the element presented as an accurate and eflicient tool in the analysis of thin to moderately thick laminated shell structures. To my parents...

Hamdallah, Jamil M.

2012-06-07T23:59:59.000Z

189

Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials  

E-Print Network [OSTI]

Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials A. Karrech a,, A. Seibi thrust is the introduc- tion of the "Chicago" law in a continuum approach to account for the ratcheting or jointly with the ratcheting effect. Non-associated plasticity is adopted since the paper mainly targets

Paris-Sud XI, Universit de

190

Finite-element discretization of a linearized 2 -D model for lubricated oil transportation  

E-Print Network [OSTI]

Finite-element discretization of a linearized 2 - D model for lubricated oil transportation V acts as a lubricant by coating the wall of the pipeline, thus preventing the oil from adhering is devoted to the numerical simulation of a linearized model for the lubricated trans- portation of heavy

Frey, Pascal

191

On a tensor-based finite element model for the analysis of shell structures  

E-Print Network [OSTI]

In the present study, we propose a computational model for the linear and nonlinear analysis of shell structures. We consider a tensor-based finite element formulation which describes the mathematical shell model in a natural and simple way by using...

Arciniega Aleman, Roman Augusto

2006-04-12T23:59:59.000Z

192

A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model  

E-Print Network [OSTI]

A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model R. BERMEJO,1 J. This model belongs to the category of energy balance models introduced independently by the climatologists M climate. The energy balance model we are dealing with consists of a two-dimensional nonlinear parabolic

Díaz, Jesús Ildefonso

193

A Finite Element Model for Ice Ball Evolution in a Multi-probe Cryosurgery  

E-Print Network [OSTI]

to intracellular ice injury for fast cooling rates, and solution effects injury for slow cooling rates. BasicallyA Finite Element Model for Ice Ball Evolution in a Multi-probe Cryosurgery RICHARD WANa, *, ZHIHONG October 2002; In final form 8 May 2003) The ice formation in a water body is examined for the computation

Wan, Richard G.

194

Thermo-elasto-plastic finite element analysis of quasi-state processes in Eulerian reference  

E-Print Network [OSTI]

Thermo-elasto-plastic finite element analysis of quasi-state processes in Eulerian reference frames ­ Incremental scheme ­ Fine mesh along entire heat source path ­ Lengthy computer runs · Elasto-Plasticity at times ti and ti-1, respectively. Penn State University 5 #12;Elasto-Plasticity Equilibrium: r(r, t) + b

Michaleris, Panagiotis

195

Local Flaps: A Real-Time Finite Element Based Solution to the Plastic Surgery  

E-Print Network [OSTI]

Local Flaps: A Real-Time Finite Element Based Solution to the Plastic Surgery Defect Puzzle fundamental challenges in plastic surgery is the alter- ation of the geometry and topology of the skin for the patient after the procedure is completed. The plastic surgeon must look at the defect created

Liblit, Ben

196

A mixed finite element discretization scheme for a concrete carbonation model with concentration-dependent porosity  

E-Print Network [OSTI]

A mixed finite element discretization scheme for a concrete carbonation model with concentration/unsaturated porous media. The special features of our problem are twofold: the reaction produces water and therefore for the case of concrete carbonation ­ one of the most important physico-chemical processes affecting

Suciu, Nicolae

197

Geological formation - drill string dynamic interaction finite-element program (GEODYN). Phase 1. Theoretical description  

SciTech Connect (OSTI)

The Theoretical Description for the GEODYN interactive finite-element computer program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates nonlinear, time-dependent, loading and boundary conditions.

Baird, J.A.; Apostal, M.C.; Rotelli, R.L. Jr.; Tinianow, M.A.; Wormley, D.N.

1984-06-01T23:59:59.000Z

198

Minimizing EIT image artefacts from mesh variability in Finite Element Models  

E-Print Network [OSTI]

artefacts which occur in electrical impedance tomography (EIT) images due to limitations in finite element R B Lionheart2 1 Systems and Computer Engineering, Carleton University, Ottawa, Canada 2 School of Mathematics, University of Manchester, UK Abstract. Electrical Impedance Tomography solves an inverse problem

Adler, Andy

199

A Finite-Element Model for Simulation of Carbon Dioxide Sequestration  

SciTech Connect (OSTI)

Herein, we present a coupled thermal-hydro-mechanical model for geological sequestration of carbon dioxide followed by the stress, deformation, and shear-slip failure analysis. This fully coupled model considers the geomechanical response, fluid flow, and thermal transport relevant to geological sequestration. Both analytical solutions and numerical approach via finite element model are introduced for solving the thermal-hydro-mechanical model. Analytical solutions for pressure, temperature, deformation, and stress field were obtained for a simplified typical geological sequestration scenario. The finite element model is more general and can be used for arbitrary geometry. It was built on an open-source finite element code, Elmer, and was designed to simulate the entire period of CO2 injection (up to decades) both stably and accuratelyeven for large time steps. The shear-slip failure analysis was implemented based on the numerical results from the finite element model. The analysis reveals the potential failure zone caused by the fluid injection and thermal effect. From the simulation results, the thermal effect is shown to enhance well injectivity, especially at the early time of the injection. However, it also causes some side effects, such as the appearance of a small failure zone in the caprock. The coupled thermal-hydro-mechanical model improves prediction of displacement, stress distribution, and potential failure zone compared to the model that neglects non-isothermal effects, especially in an area with high geothermal gradient.

Bao, Jie; Xu, Zhijie; Fang, Yilin

2014-09-01T23:59:59.000Z

200

Modeling of board-level package by Finite Element Analysis and laser interferometer measurements  

E-Print Network [OSTI]

and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai be simulated by an equivalent Finite Element Analysis (FEA) model of the board-level package, in which detailed layer structure of the Print Circuit Board (PCB), signal wires and through-holes were ignored

Cao, Wenwu

Note: This page contains sample records for the topic "finite element method" 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

Finite element strategies for the efficient analysis and evaluation of solar collector structures  

SciTech Connect (OSTI)

Concentrating or reflecting structures for solar energy systems must be evaluated as to their structural integrity and optical performance. Computer studies can be used as an integral part of these evaluations. The computer studies make use of finite element structural codes coupled with post-processors that calculate optical data. If the analysis of a solar structure is to be carried out in an efficient manner, these computer codes must have certain capabilities. A number of solar energy projects at Sandia National Laboratories have made extensive use of finite element analyses. The analyses have been useful in evaluating design concepts which hold promise for large scale use in solar energy projects. Analysis procedures have been developed for some structures so that evaluations can be carried out in a straightforward manner.

Koteras, J. R.

1980-01-01T23:59:59.000Z

202

Modeling of reactor components using FIDAP: a finite element computer code  

E-Print Network [OSTI]

of MASTER OF SCIENCE May 1989 Major Subject: Nuclear Engineering MODELING OF REACTOR COMPONENTS USING FIDAP - A FINITE ELEMENT COMPUTER CODE A Thesis by ANAND GANGADHARAN Approved as to style and content by. assin A. Hassan (Chair of Committee... of Nuclear Engineering, Texas ASM University. I feel elated in placing on record, my direct and totally involved interaction with the Chairman of my committee, Prof. Y. A. Hassan. I am grateful to him for his constant and unreserved encouragement...

Gangadharan, Anand

1989-01-01T23:59:59.000Z

203

Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design of a fluid-flow control nano-valve  

E-Print Network [OSTI]

of a fluid-flow control nano-valve M. Grujicica,, G. Caoa, B. Pandurangana, W.N. Royb a Department A finite element method-based procedure is developed for the design of molecularly functionalized nano-size devices. The procedure is aimed at the single-walled carbon nano-tubes (SWCNTs) used in the construction

Grujicic, Mica

204

R.H. Saunders GS concrete growth mitigation project instrumentation and finite element analysis  

SciTech Connect (OSTI)

In 1991, concrete expansion due to Alkali-Silica Reaction (ASR), was diagnosed as the cause of operational and structural problems at R.H. Saunders Generating Station. Reestablishment of contraction joints between the generating units by cutting slots was initiated in January 1993 to relieve accumulated stresses and allow further expansion without deforming the turbine-generators. An integral part of the remedial measure is the installation of an extensive instrumentation system and development of detailed finite element models of the powerhouse structures. In total, two hundred and thirty five instruments have been installed. The instruments include surface extensometers, borehole extensometers, crackmeters, stressmeters, pendulums, thermocouples, borehole convergence meters and strain gauges. All the instruments are monitored continuously by an Automatic Data Acquisition System (ADAS) which allows instrument data to be evaluated remotely. This instrumentation system is being used to collect data on the structural concrete expansion and response to slot cutting. To complement the instrumentation data, three different finite element models have been developed for use. The models range from a very detailed representation of a single powerhouse unit to a less detailed model of the sixteen-unit powerhouse. The finite element models have been calibrated to reflect measured data and subsequently used to estimate the location and frequency of future cuts.

Adeghe, L.; Hindy, A.; Ho, M.S. [Hydroelectric Business Unit, Ontario Hydro, Toronto, Ontario (Canada)

1995-12-31T23:59:59.000Z

205

Diffusion Synthetic Acceleration for High-Order Discontinuous Finite Element SN Transport Schemes and Application to Locally Refined Unstructured Meshes  

SciTech Connect (OSTI)

Diffusion synthetic acceleration (DSA) schemes compatible with adaptive mesh refinement (AMR) grids are derived for the SN transport equations discretized using high-order discontinuous finite elements. These schemes are directly obtained from the discretized transport equations by assuming a linear dependence in angle of the angular flux along with an exact Fick's law and, therefore, are categorized as partially consistent. These schemes are akin to the symmetric interior penalty technique applied to elliptic problems and are all based on a second-order discontinuous finite element discretization of a diffusion equation (as opposed to a mixed or P1 formulation). Therefore, they only have the scalar flux as unknowns. A Fourier analysis has been carried out to determine the convergence properties of the three proposed DSA schemes for various cell optical thicknesses and aspect ratios. Out of the three DSA schemes derived, the modified interior penalty (MIP) scheme is stable and effective for realistic problems, even with distorted elements, but loses effectiveness for some highly heterogeneous configurations. The MIP scheme is also symmetric positive definite and can be solved efficiently with a preconditioned conjugate gradient method. Its implementation in an AMR SN transport code has been performed for both source iteration and GMRes-based transport solves, with polynomial orders up to 4. Numerical results are provided and show good agreement with the Fourier analysis results. Results on AMR grids demonstrate that the cost of DSA can be kept low on locally refined meshes.

Yaqi Wang; Jean C. Ragusa

2011-10-01T23:59:59.000Z

206

Modeling brittle fracture, slip weakening, and variable friction in geomaterials with an embedded strong discontinuity finite element.  

SciTech Connect (OSTI)

Localized shear deformation plays an important role in a number of geotechnical and geological processes. Slope failures, the formation and propagation of faults, cracking in concrete dams, and shear fractures in subsiding hydrocarbon reservoirs are examples of important effects of shear localization. Traditional engineering analyses of these phenomena, such as limit equilibrium techniques, make certain assumptions on the shape of the failure surface as well as other simplifications. While these methods may be adequate for the applications for which they were designed, it is difficult to extrapolate the results to more general scenarios. An alternative approach is to use a numerical modeling technique, such as the finite element method, to predict localization. While standard finite elements can model a wide variety of loading situations and geometries quite well, for numerical reasons they have difficulty capturing the softening and anisotropic damage that accompanies localization. By introducing an enhancement to the element in the form of a fracture surface at an arbitrary position and orientation in the element, we can regularize the solution, model the weakening response, and track the relative motion of the surfaces. To properly model the slip along these surfaces, the traction-displacement response must be properly captured. This report focuses on the development of a constitutive model appropriate to localizing geomaterials, and the embedding of this model into the enhanced finite element framework. This modeling covers two distinct phases. The first, usually brief, phase is the weakening response as the material transitions from intact continuum to a body with a cohesionless fractured surface. Once the cohesion has been eliminated, the response along the surface is completely frictional. We have focused on a rate- and state-dependent frictional model that captures stable and unstable slip along the surface. This model is embedded numerically into the element using a generalized trapezoidal formulation. While the focus is on the constitutive model of interest, the framework is also developed for a general surface response. This report summarizes the major research and development accomplishments for the LDRD project titled 'Cohesive Zone Modeling of Failure in Geomaterials: Formulation and Implementation of a Strong Discontinuity Model Incorporating the Effect of Slip Speed on Frictional Resistance'. This project supported a strategic partnership between Sandia National Laboratories and Stanford University by providing funding for the lead author, Craig Foster, during his doctoral research.

Regueiro, Richard A. (University of Colorado, Boulder, CO); Borja, R. I. (Stanford University, Stanford, CA); Foster, C. D. (Stanford University, Stanford, CA)

2006-10-01T23:59:59.000Z

207

Operator-adapted finite element wavelets : theory and applications to a posteriori error estimation and adaptive computational modeling  

E-Print Network [OSTI]

We propose a simple and unified approach for a posteriori error estimation and adaptive mesh refinement in finite element analysis using multiresolution signal processing principles. Given a sequence of nested discretizations ...

Sudarshan, Raghunathan, 1978-

2005-01-01T23:59:59.000Z

208

Adaptive Finite Element Modeling Techniques for the Poisson-Boltzmann Equation  

E-Print Network [OSTI]

We develop an efficient and reliable adaptive finite element method (AFEM) for the nonlinear Poisson-Boltzmann equation (PBE). We first examine the regularization technique of Chen, Holst, and Xu; this technique made possible the first a priori pointwise estimates and the first complete solution and approximation theory for the Poisson-Boltzmann equation. It also made possible the first provably convergent discretization of the PBE, and allowed for the development of a provably convergent AFEM for the PBE. However, in practice the regularization turns out to be numerically ill-conditioned. In this article, we examine a second regularization, and establish a number of basic results to ensure that the new approach produces the same mathematical advantages of the original regularization, without the ill-conditioning property. We then design an AFEM scheme based on the new regularized problem, and show that the resulting AFEM scheme is accurate and reliable, by proving a contraction result for the error. This result, which is one of the first results of this type for nonlinear elliptic problems, is based on using continuous and discrete a priori pointwise estimates to establish quasi-orthogonality. To provide a high-quality geometric model as input to the AFEM algorithm, we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures, based on the intrinsic local structure tensor of the molecular surface. The stability advantages of the new regularization are demonstrated using an FETK-based implementation, through comparisons with the original regularization approach for a model problem. The convergence and accuracy of the overall AFEM algorithm is also illustrated by numerical approximation of electrostatic solvation energy for an insulin protein.

Michael Holst; James Andrew McCammon; Zeyun Yu; Yongcheng Zhou; Yunrong Zhu

2010-09-30T23:59:59.000Z

209

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

210

Method and system for processing optical elements using magnetorheological finishing  

DOE Patents [OSTI]

A method of finishing an optical element includes mounting the optical element in an optical mount having a plurality of fiducials overlapping with the optical element and obtaining a first metrology map for the optical element and the plurality of fiducials. The method also includes obtaining a second metrology map for the optical element without the plurality of fiducials, forming a difference map between the first metrology map and the second metrology map, and aligning the first metrology map and the second metrology map. The method further includes placing mathematical fiducials onto the second metrology map using the difference map to form a third metrology map and associating the third metrology map to the optical element. Moreover, the method includes mounting the optical element in the fixture in an MRF tool, positioning the optical element in the fixture; removing the plurality of fiducials, and finishing the optical element.

Menapace, Joseph Arthur; Schaffers, Kathleen Irene; Bayramian, Andrew James; Molander, William A

2012-09-18T23:59:59.000Z

211

Parallel 3D Finite Element Numerical Modelling of DC Electron Guns  

SciTech Connect (OSTI)

In this paper we present Gun3P, a parallel 3D finite element application that the Advanced Computations Department at the Stanford Linear Accelerator Center is developing for the analysis of beam formation in DC guns and beam transport in klystrons. Gun3P is targeted specially to complex geometries that cannot be described by 2D models and cannot be easily handled by finite difference discretizations. Its parallel capability allows simulations with more accuracy and less processing time than packages currently available. We present simulation results for the L-band Sheet Beam Klystron DC gun, in which case Gun3P is able to reduce simulation time from days to some hours.

Prudencio, E.; Candel, A.; Ge, L.; Kabel, A.; Ko, K.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; /SLAC

2008-02-04T23:59:59.000Z

212

PARALLEL COMPUTING OF UNSATURATED SOILS USING ELEMENT-BY-ELEMENT AND DOMAIN DEOMPOSITON METHODS  

E-Print Network [OSTI]

the processors with minimum data exchanges and load balancing. The linear system of equations was solved using and primary unknowns. The mass balance of water flow leads to the following equation: ( ) 0=+ ww wr div t n as in compacted soils used as fill material. The accurate analysis of unsaturated soils by the finite element

Augarde, Charles

213

Extended Finite Element Method for Fretting Fatigue Crack Propagation  

E-Print Network [OSTI]

.D. Denia a , F.J. Fuenmayor a aDepartamento de Ingenier´ia Mec´anica y de Materiales Universidad Polit´ecnica de Valencia, Camino de Vera, 46022 Valencia, Spain. bDepartment of Civil and Environmental

Sukumar, N.

214

An Abaqus implementation of the extended finite element method  

E-Print Network [OSTI]

. Taranc´on a , F. J. Fuenmayor a aDepartamento de Ingenier´ia Mec´anica y de Materiales Universidad Polit´ecnica de Valencia, Camino de Vera, 46022 Valencia, Spain. bDepartment of Civil and Environmental

Sukumar, N.

215

FLUX RECOVERY FROM PRIMAL HYBRID FINITE ELEMENT METHODS #  

E-Print Network [OSTI]

and Statistics, Bowling Green State University, Bowling Green, OH (chou@bgnet.bgsu.edu). The research

Chou, So-Hsiang

216

A finite element method using singular functions for the Poisson ...  

E-Print Network [OSTI]

1Department of Mathematics; Purdue University; 1395 Mathematical Science ... Contract=grant sponsor: U.S. Department of Energy by Lawrence Livermore ...... Djaoua M. Equations Int?egrales pour un Probleme Singulier dans le Plan.

2002-09-05T23:59:59.000Z

217

Finite Element Methods for Nonlinear Acoustics in Fluids  

E-Print Network [OSTI]

resonating acoustic cavity, and a coupled elastic/acoustic system consisting of ... linear terms in these wave equations imply that the sound speed depends on the ... have zero shear modulus, this approach suffers from an infinite dimensional...

218

The Finite Volume Element Method for Diffusion ... - Purdue University  

E-Print Network [OSTI]

Dec 6, 2003 ... SIAM Journal on Numerical Analysis is currently published by ... was introduced several years earlier in the mechanical engineering literature While ... tCourant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New .... bid) = we vent-2%] / mews, .... Heat Transfer, 3 (1980), pp.

219

Discontinuous finite element methods for particle transport problems  

E-Print Network [OSTI]

, and intcgratc over cell k: dxdy w, (x, y) lA. &iF (x, y, 0) F o (x, g) 8 (x, y, n)] V? = J x I/ ?(x, t/)r/(x, y). (5) We then apply Gauss's theorem to the leakage term and drop arguments of functions for simplicity: (6) where n is the outward unit normal... on the boundary of cell k. We refer Eq. (6) as the (k, i)*th weighted residual. We now insert DFEM approximation, Eq. (2), to the weighted residual equation (6): /?, ju, , ""' ? f dt w, n. H~'~'"' +P d? d'?9[ ? ~&$ f2 +u~, , +?, , o~l k k f dr, dy u...

Stone, Hiromi

2012-06-07T23:59:59.000Z

220

Coupling of finite element and boundary integral methods for ...  

E-Print Network [OSTI]

Oct 8, 2009 ... sparse, and banded matrix; A12? is an Nn ? Ne rectangular and sparse ... ple MATLAB mesh generator distmesh2d by Persson and Strang [38] is ... 2 shows the graphs of the real part and the imaginary part of the field.

"Peijun Li"

2009-11-09T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Experimental verification of finite element enhancement and MAC methods  

E-Print Network [OSTI]

APPENDIX B APPENDIX C VITA 133 135 139 147 203 LIST OF TABLES Table 1. MAC on Fixed-free Beam Mode Shapes (DOF=10) . . Page 22 2. MAC on Fixed-free Beam Mode Shapes (DOF=100) . 3. MAC on Free-free Beam Mode Shapes (DOF =10) 4. MAC on Free...-free Beam Mode Shapes (DOF = 100) 22 23 23 5. Comparison of Natural Frequencies for Simulated Pipe Model 6. MAC Test Between Berman's Improved and the "Measured" Mode Shapes 36 - Simulated Pipe Model 37 7. MAC Test Between Creamer's Improved...

Ibrahim, Syed Azman

1991-01-01T23:59:59.000Z

222

Adaptive Finite Element Method for Time ... - Purdue University  

E-Print Network [OSTI]

Oct 11, 2013 ... recovery-based estimator (Nicaise et al 2005) ?2. K = G(?uh) ..... Answer: No. For the same relative error 0.2, the error heat map shows that.

Shuhao Cao supervised under Professor Cai

2013-10-31T23:59:59.000Z

223

Discontinuous Galerkin Subgrid Finite Element Method for Heterogeneous Brinkman's  

E-Print Network [OSTI]

made of glass or mineral wool with porosity 0.99, or open foams with porosity above 0.95, see Fig. 1 15 Fig. 1. Microstructure of industrial foams Fig. 2. Microstructure and marcostructure of mineral

Lazarov, Raytcho

224

Determining finite volume elements for the 2D Navier-Stokes equations  

SciTech Connect (OSTI)

We consider the 2D Navier-Stokes equations on a square with periodic boundary conditions. Dividing the square into N equal subsquares, we show that if the asymptotic behavior of the average of solutions on these subsquares (finite volume elements) is known, then the large time behavior of the solution itself is completely determined, provided N is large enough. We also establish a rigorous upper bound for N needed to determine the solutions to the Navier-Stokes equation in terms of the physical parameters of the problem. 34 refs.

Jones, D.A. (California Univ., Irvine, CA (United States). Dept. of Mathematics); Titi, E.S. (California Univ., Irvine, CA (United States). Dept. of Mathematics Cornell Univ., Ithaca, NY (United States). Mathematical Sciences Inst.)

1991-01-01T23:59:59.000Z

225

An explicit finite element formulation for dynamic strain localization and damage evolution in metals  

SciTech Connect (OSTI)

An explicit finite element formulation, used to study the behavior and failure mechanisms of metallic materials under high strain rate loading, is presented. The formulation is based on the assumed-strain approach of Fish and Belytschko [1988], which allows localization bands to be embedded within an element, thereby alleviating mesh sensitivity and reducing the required computational effort. The behavior of the material outside localization bands (and of the virgin material prior to the onset of strain localization) is represented using a Gurson-type coupled plasticity-damage model based on the work of Johnson and Addessio [1988]. Assuming adiabatic conditions, the response of the localization band material is represented by a set of constitutive equations for large elasticviscoplastic deformations in metals at high strain rates and high homologous temperatures (see Brown et al. [1989]). Computational results are compared to experimental data for different metallic alloys to illustrate the advantages of the proposed modeling strategy.

Mourad, Hashem M [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory

2010-12-16T23:59:59.000Z

226

Generalization of the Atkinson-Wilcox Theorem and the Development of a Novel Scaled Boundary Finite Element Formulation for the Numerical Simulation of Electromagnetic Radiation  

E-Print Network [OSTI]

The Scaled Boundary Finite Element Method is a novel semi-analytical method jointly developed by Chongmin Song and John P Wolf to solve problems in elastodynamics and allied problems in civil engineering. This novel method has been recently reformulated for the following categories of problems in electromagnetics: (1) Determination of Eigen values of metallic cavity structures, 2) Full wave analysis of Shielded micro-strip transmission line structures, and Very Large Scale Integrated Circuit (VLSI) interconnects, and 3) Full wave analysis of periodic structures. In this paper, a novel Scaled Boundary Finite Element formulation is developed for the numerical simulation of the time harmonic electromagnetic radiation in free space from metallic structures of arbitrary shape. The development of the novel formulation necessitates the generalization of the familiar Atkinson-Wilcox radiation series expansion so as to be applicable for arbitrary boundary circumscribing the source of radiation.

Rajan, V S P

2006-01-01T23:59:59.000Z

227

Efficient Computation of Info-Gap Robustness for Finite Element Models  

SciTech Connect (OSTI)

A recent research effort at LANL proposed info-gap decision theory as a framework by which to measure the predictive maturity of numerical models. Info-gap theory explores the trade-offs between accuracy, that is, the extent to which predictions reproduce the physical measurements, and robustness, that is, the extent to which predictions are insensitive to modeling assumptions. Both accuracy and robustness are necessary to demonstrate predictive maturity. However, conducting an info-gap analysis can present a formidable challenge, from the standpoint of the required computational resources. This is because a robustness function requires the resolution of multiple optimization problems. This report offers an alternative, adjoint methodology to assess the info-gap robustness of Ax = b-like numerical models solved for a solution x. Two situations that can arise in structural analysis and design are briefly described and contextualized within the info-gap decision theory framework. The treatments of the info-gap problems, using the adjoint methodology are outlined in detail, and the latter problem is solved for four separate finite element models. As compared to statistical sampling, the proposed methodology offers highly accurate approximations of info-gap robustness functions for the finite element models considered in the report, at a small fraction of the computational cost. It is noted that this report considers only linear systems; a natural follow-on study would extend the methodologies described herein to include nonlinear systems.

Stull, Christopher J. [Los Alamos National Laboratory; Hemez, Francois M. [Los Alamos National Laboratory; Williams, Brian J. [Los Alamos National Laboratory

2012-07-05T23:59:59.000Z

228

Multigrid and Krylov Solvers for Large Scale Finite Element Groundwater Flow Simulations on Distributed Memory Parallel Platforms  

SciTech Connect (OSTI)

In this report we present parallel solvers for large linear systems arising from the finite-element discretization of the three-dimensional steady-state groundwater flow problem. Our solvers are based on multigrid and Krylov subspace methods. The parallel implementation is based on a domain decomposition strategy with explicit message passing using NX and MPI libraries. We have tested our parallel implementations on the Intel Paragon XP/S 150 supercomputer using up to 1024 parallel processors and on other parallel platforms such as SGI/Power Challenge Array, Cray/SGI Origin 2000, Convex Exemplar SPP-1200, and IBM SP using up to 64 processors. We show that multigrid can be a scalable algorithm on distributed memory machines. We demonstrate the effectiveness of parallel multigrid based solvers by solving problems requiring more than 70 million nodes in less than a minute. This is more than 25 times faster than the diagonal preconditioned conjugate gradient method which is one of the more popular methods for large sparse linear systems. Our results also show that multigrid as a stand alone solver works best for problems with smooth coefficients, but for rough coefficients it is best used as a preconditioner for a Krylov subspace method such as the conjugate gradient method. We show that even for extremely heterogeneous systems the multigrid pre-conditioned conjugate gradient method is at least 10 times faster than the diagonally preconditioned conjugate gradient method.

Mahinthakumar, K.

1997-01-01T23:59:59.000Z

229

Automation of the matrix element reweighting method  

E-Print Network [OSTI]

Matrix element reweighting is a powerful experimental technique widely employed to maximize the amount of information that can be extracted from a collider data set. We present a procedure that allows to automatically evaluate the weights for any process of interest in the standard model and beyond. Given the initial, intermediate and final state particles, and the transfer functions for the final physics objects, such as leptons, jets, missing transverse energy, our algorithm creates a phase-space mapping designed to efficiently perform the integration of the squared matrix element and the transfer functions. The implementation builds up on MadGraph, it is completely automatized and publicly available. A few sample applications are presented that show the capabilities of the code and illustrate the possibilities for new studies that such an approach opens up.

P. Artoisenet; V. Lematre; F. Maltoni; O. Mattelaer

2011-02-01T23:59:59.000Z

230

A parallel high-order accurate finite element nonlinear Stokes ice sheet model and benchmark experiments  

SciTech Connect (OSTI)

The numerical modeling of glacier and ice sheet evolution is a subject of growing interest, in part because of the potential for models to inform estimates of global sea level change. This paper focuses on the development of a numerical model that determines the velocity and pressure fields within an ice sheet. Our numerical model features a high-fidelity mathematical model involving the nonlinear Stokes system and combinations of no-sliding and sliding basal boundary conditions, high-order accurate finite element discretizations based on variable resolution grids, and highly scalable parallel solution strategies, all of which contribute to a numerical model that can achieve accurate velocity and pressure approximations in a highly efficient manner. We demonstrate the accuracy and efficiency of our model by analytical solution tests, established ice sheet benchmark experiments, and comparisons with other well-established ice sheet models.

Leng, Wei [Chinese Academy of Sciences; Ju, Lili [University of South Carolina; Gunzburger, Max [Florida State University; Price, Stephen [Los Alamos National Laboratory; Ringler, Todd [Los Alamos National Laboratory,

2012-01-01T23:59:59.000Z

231

Finite Element Analysis of the Amontons-Coulomb's Model using Local and Global Friction Tests  

SciTech Connect (OSTI)

In spite of the abundant number of experimental friction tests that have been reported, the contact with friction modeling persists to be one of the factors that determine the effectiveness of sheet metal forming simulation. This difficulty can be understood due to the nature of the friction phenomena, which comprises the interaction of different factors connected to both sheet and tools' surfaces. Although in finite element numerical simulations friction models are commonly applied at the local level, they normally rely on parameters identified based on global experimental tests results. The aim of this study is to analyze the applicability of the Amontons-Coulomb's friction coefficient identified using complementary tests: (i) load-scanning, at the local level and (ii) draw-bead, at the global level; to the numerical simulation of sheet metal forming processes.

Oliveira, M. C.; Menezes, L. F.; Ramalho, A. [CEMUC, Department of Mechanical Engineering, University of Coimbra, Polo II, Rua Luis Reis Santos, Pinhal de Marrocos, 3030-788 Coimbra (Portugal); Alves, J. L. [Department of Mechanical Engineering, University of Minho, Campus de Azurem, 4800-058, Guimaraes (Portugal)

2011-05-04T23:59:59.000Z

232

Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model  

E-Print Network [OSTI]

reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...

O'Neal, D.L.; Bassiouny, R.

233

Use of laboratory triaxial-creep data and finite-element analysis to predict observed creep behavior of leached salt caverns  

SciTech Connect (OSTI)

An increasing interest is being shown worldwide in using leached salt caverns to store oil and natural gas. A critical factor in the use of existing caverns and the design of new ones is the creep behavior of the salt surrounding the caverns. An understanding of this behavior is being gained by using laboratory triaxial creep data as material property input to finite element computer programs designed to calculate displacements and stresses due to creep. An important step in verifying these predictive methods is the comparison of field data from existing caverns with finite element analyses which incorporate the material properties and geometry of each site. This comparison has been made for caverns in the Eminence Dome (Mississippi), West Hackberry Dome (Louisiana), and Bayou Chocktaw Dome (Louisiana) with reasonably good correlation being obtained between measured and predicted volumetric response of the caverns. These comparisons are discussed in this paper.

Preece, D.S.; Stone, C.M.

1982-08-01T23:59:59.000Z

234

A mimetic finite difference method for the Stokes problem with elected edge bubbles  

SciTech Connect (OSTI)

A new mimetic finite difference method for the Stokes problem is proposed and analyzed. The unstable P{sub 1}-P{sub 0} discretization is stabilized by adding a small number of bubble functions to selected mesh edges. A simple strategy for selecting such edges is proposed and verified with numerical experiments. The discretizations schemes for Stokes and Navier-Stokes equations must satisfy the celebrated inf-sup (or the LBB) stability condition. The stability condition implies a balance between discrete spaces for velocity and pressure. In finite elements, this balance is frequently achieved by adding bubble functions to the velocity space. The goal of this article is to show that the stabilizing edge bubble functions can be added only to a small set of mesh edges. This results in a smaller algebraic system and potentially in a faster calculations. We employ the mimetic finite difference (MFD) discretization technique that works for general polyhedral meshes and can accomodate non-uniform distribution of stabilizing bubbles.

Lipnikov, K [Los Alamos National Laboratory; Berirao, L [DIPARTMENTO DI MATERMATICA

2009-01-01T23:59:59.000Z

235

Application of the discontinuous spectral Galerkin method to groundwater flow  

E-Print Network [OSTI]

method uses a finite-element discretization of the groundwater flow domain with basis functions with a standard finite-element method and a mixed finite-element method. Numerical sim- ulations show that the discontinuous spectral Galerkin approximation is more efficient than the standard finite-element method (in

Fagherazzi, Sergio

236

(a finite-element computer code for the computation of visco-plastic creeping flows with applications to tectonics)  

E-Print Network [OSTI]

SOPALE (a finite-element computer code for the computation of visco-plastic creeping flows are bracketed like this ** 1. What is SOPALE? SOPALE is a computer code written in Fortran 77 which computes of the code history and contributors ** my comments, which may be eliminated or used at your discretion

Beaumont, Christopher

237

A two-dimensional finite element thermomechanical approach to a global stress-strain analysis of steel continuous casting  

E-Print Network [OSTI]

of steel continuous casting Michel Bellet, Alban Heinrich Ecole des Mines de Paris, Centre de Mise en Forme.bellet@ensmp.fr Synopsis This paper addresses the two-dimensional finite element simulation of steel continuous casting state (temperature, deformation, stresses) of steel all along the continuous casting machine. Both plane

Boyer, Edmond

238

A ThreeDimensional Finite Element Simulation for Transport of Nuclear Waste Contamination in Porous Media \\Lambda  

E-Print Network [OSTI]

A Three­Dimensional Finite Element Simulation for Transport of Nuclear Waste Contamination for transport of nuclear­waste contamination in three­dimensional porous media are presented with a description of contamination of groundwater by high­level nuclear waste and a wide variety of other sources makes a proper

Ewing, Richard E.

239

A characteristic/finite element algorithm for time-dependent 3-D advection-dominated transport using unstructured grids  

E-Print Network [OSTI]

number mass/heat transport in a fully developed pipe flow. 2002 Elsevier Science B.V. All rights of physics and engineering. Examples are heat transfer processes in rubber extrusion, plastic castingA characteristic/finite element algorithm for time-dependent 3-D advection-dominated transport

Mofrad, Mohammad R. K.

240

Resolution of grain scale interactions using the Discrete Element Method  

E-Print Network [OSTI]

Granular materials are an integral part of many engineering systems. Currently, a popular tool for numerically investigating granular systems is the Discrete Element Method (DEM). Nearly all implementations of the DEM, ...

Johnson, Scott M. (Scott Matthew), 1978-

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Urbana, IL); Lee, Keon Jae (Savoy, IL); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Champaign, IL); Zhu, Zhengtao (Urbana, IL)

2009-11-24T23:59:59.000Z

242

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2013-05-14T23:59:59.000Z

243

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2014-03-04T23:59:59.000Z

244

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Durham, NC); Lee, Keon Jae (Daejeon, KR); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Raleigh, NC); Zhu, Zhengtao (Urbana, IL)

2011-07-19T23:59:59.000Z

245

Finite element modelling of transport and drift effects in tokamak divertor and SOL  

SciTech Connect (OSTI)

A finite element code is used to simulate transport of a single-species plasma in the edge and divertor of a tokamak. The physical model is based on Braginskii`s fluid equations for the conservation of particles, parallel momentum, ion and electron energy. In modelling recycling, transport of neutral density and energy is treated in the diffusion approximation. The electrostatic potential is obtained from the generalized Ohm`s law. It is used to compute the electric field and the associated E x B drift. In a first approximation, transport is assumed to be ambipolar. The system of equations is discretized on an unstructured triangular mesh, thus permitting good spatial resolution near the X-point and an accurate description of divertor plates of arbitrary shape. Special care must be taken to prevent numerical corruption of the highly anisotropic thermal diffusion. Comparisons will be made between simulations and experimental results from TdeV. This will focus, in particular, on density and temperature profiles at the divertor plates, and on the plasma parallel velocity in the SOL. The asymmetry in the power deposited to the inner and outer divertors and the effect of magnetic field reversal will be considered. Comparisons with B2-Eirene simulation results will also be presented.

Simard, M.; Marchand, R. [INRS-Energie et Materiaux, Varennes, Quebec (Canada); Boucher, C.; Gunn, J.P. [Centre Canadien de Fusion Magnetique, Varennes, Quebec (Canada)] [and others

1996-12-31T23:59:59.000Z

246

Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.  

SciTech Connect (OSTI)

Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

2012-01-01T23:59:59.000Z

247

Quantum-corrected drift-diffusion models: Solution fixed point map and finite element approximation  

SciTech Connect (OSTI)

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in [C. de Falco, A.L. Lacaita, E. Gatti, R. Sacco, Quantum-Corrected Drift-Diffusion Models for Transport in Semiconductor Devices, J. Comp. Phys. 204 (2) (2005) 533-561] for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as being a fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a numerical tool, which was lacking in previous non-constructive proofs [N.B. Abdallah, A. Unterreiter, On the stationary quantum drift-diffusion model, Z. Angew. Math. Phys. 49 (1998) 251-275, R. Pinnau, A. Unterreiter, The stationary current-voltage characteristics of the quantum drift-diffusion model, SIAM J. Numer. Anal. 37 (1) (1999) 211-245]. The finite element approximation of the GGM is illustrated, and the main properties of the numerical fixed point map (discrete maximum principle and order of convergence) are discussed. Numerical results on realistic nanoscale devices are included to support the theoretical conclusions.

Falco, Carlo de [School of Mathematical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Jerome, Joseph W. [Department of Mathematics, Northwestern University, 2033 Sheridan Road, Evanston, IL 60208-2730 (United States); Sacco, Riccardo [Dipartimento di Matematica 'F.Brioschi', Politecnico di Milano, via Bonardi 9, 20133 Milano (Italy)], E-mail: riccardo.sacco@polimi.it

2009-03-20T23:59:59.000Z

248

Finite element analyses of continuous filament ties for masonry applications : final report for the Arquin Corporation.  

SciTech Connect (OSTI)

Finite-element analyses were performed to simulate the response of a hypothetical vertical masonry wall subject to different lateral loads with and without continuous horizontal filament ties laid between rows of concrete blocks. A static loading analysis and cost comparison were also performed to evaluate optimal materials and designs for the spacers affixed to the filaments. Results showed that polypropylene, ABS, and polyethylene (high density) were suitable materials for the spacers based on performance and cost, and the short T-spacer design was optimal based on its performance and functionality. Simulations of vertical walls subject to static loads representing 100 mph winds (0.2 psi) and a seismic event (0.66 psi) showed that the simulated walls performed similarly and adequately when subject to these loads with and without the ties. Additional simulations and tests are required to assess the performance of actual walls with and without the ties under greater loads and more realistic conditions (e.g., cracks, non-linear response).

Quinones, Armando, Sr. (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei

2008-08-01T23:59:59.000Z

249

Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach  

E-Print Network [OSTI]

-facing step, two-dimensional flow past a stationary circular cylinder, three-dimensional flow past a sphere and two and three-dimensional natural convection in an enclosure with/without immersed body. The numerical results obtained with the discussed IFEM...

Frisani, Angelo 1980-

2012-12-07T23:59:59.000Z

250

Finite element analysis and design of large diameter flexible vertical pipes subjected to incremental compacted backfill loads and creep effects  

E-Print Network [OSTI]

FINITE ELEMENT ANALYSIS AND DESiGN OF LARGE DIANETER FLEXIBLE VERTICAL PIPES SUBJECTED TO INCREMENTAL COMPACTED BACKFILL LOADS AND CREEP EFFECTS A Thesis by MOHAMMAD KABIR HOSSAIN Submitted to the Office of Graduate Studies of Texas A... BACKFILL LOADS AND CREEP EFFECTS A Thesis by MOHAMMAD KABIR HOSSAIN Approved as to sty1e and content by: R be+r L. Lytton (Chair of Committee) Ozden 0. Ochoa (Member) Derek V. Morris (Member) ames T P Yao (Head of rtment) ABSTRACT Finite...

Hossain, Mohammad Kabir

1990-01-01T23:59:59.000Z

251

Method and system for high power reflective optical elements  

DOE Patents [OSTI]

A method of repairing damage in an optical element includes providing a laser system including at least one optical element having a coating layer having an incident light surface and directing a laser pulse from the laser system to impinge on the incident light surface. The method also includes sustaining damage to a portion of the incident light surface and melting the damaged portion of the incident light surface and a region adjacent to the damaged portion. The method further includes flowing material from the region adjacent the damaged portion to the damaged portion and solidifying the material in the damaged portion and the region adjacent to the damaged portion.

Demos, Stavros G.; Rubenchik, Alexander M.; Negres, Raluca A.

2013-03-12T23:59:59.000Z

252

FINITE ELEMENT ANALYSIS OF JNES/NUPEC SEISMIC SHEAR WALL CYCLIC AND SHAKING TABLE TEST DATA.  

SciTech Connect (OSTI)

This paper describes a finite element analysis to predict the JNES/NUPEC cyclic and shaking table RC shear wall test data, as part of a collaborative agreement between the U.S. NRC and JNES to study seismic issues important to the safe operation of commercial nuclear power plant (NPP) structures, systems and components (SSC). The analyses described in this paper were performed using ANACAP reinforced concrete models. The paper describes the ANACAP analysis models and discusses the analysis comparisons with the test data. The ANACAP capability for modeling nonlinear cyclic characteristics of reinforced concrete shear wall structures was confirmed by the close comparisons between the ANACAP analysis results and the JNES/NUPEC cyclic test data. Reasonable agreement between the analysis results and the test data was demonstrated for the hysteresis loops and the shear force orbits, in terms of both the overall shape and the cycle-to-cycle comparisons. The ANACAP simulation analysis of the JNES/NUPEC shaking table test was also performed, which demonstrated that the ANACAP dynamic analysis with concrete material model is able to capture the progressive degrading behavior of the shear wall as indicated from the test data. The ANACAP analysis also predicted the incipient failure of the shear wall, reasonably close to the actual failure declared for the test specimen. In summary, the analyses of the JNES/NUPEC cyclic and shaking table RC shear wall tests presented in this paper have demonstrated the state-of-the-art analysis capability for determining the seismic capacity of RC shear wall structures.

XU,J.; NIE, J.; HOFMAYER, C.; ALI, S.

2007-04-12T23:59:59.000Z

253

Best Practices for Finite Element Analysis of Spent Nuclear Fuel Transfer, Storage, and Transportation Systems  

SciTech Connect (OSTI)

Storage casks and transportation packages for spent nuclear fuel (SNF) are designed to confine SNF in sealed canisters or casks, provide structural integrity during accidents, and remove decay through a storage or transportation overpack. The transfer, storage, and transportation of SNF in dry storage casks and transport packages is regulated under 10 CFR Part 72 and 10 CFR Part 71, respectively. Finite Element Analysis (FEA) is used with increasing frequency in Safety Analysis Reports and other regulatory technical evaluations related to SNF casks and packages and their associated systems. Advances in computing power have made increasingly sophisticated FEA models more feasible, and as a result, the need for careful review of such models has also increased. This paper identifies best practice recommendations that stem from recent NRC review experience. The scope covers issues common to all commercially available FEA software, and the recommendations are applicable to any FEA software package. Three specific topics are addressed: general FEA practices, issues specific to thermal analyses, and issues specific to structural analyses. General FEA practices covers appropriate documentation of the model and results, which is important for an efficient review process. The thermal analysis best practices are related to cask analysis for steady state conditions and transient scenarios. The structural analysis best practices are related to the analysis of casks and associated payload during standard handling and drop scenarios. The best practices described in this paper are intended to identify FEA modeling issues and provide insights that can help minimize associated uncertainties and errors, in order to facilitate the NRC licensing review process.

Bajwa, Christopher S.; Piotter, Jason; Cuta, Judith M.; Adkins, Harold E.; Klymyshyn, Nicholas A.; Fort, James A.; Suffield, Sarah R.

2010-08-11T23:59:59.000Z

254

A stochastic method for computing hadronic matrix elements  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We present a stochastic method for the calculation of baryon 3-point functions which is an alternative to the typically used sequential method offering more versatility. We analyze the scaling of the error of the stochastically evaluated 3-point function with the lattice volume and find a favorable signal to noise ratio suggesting that the stochastic method can be extended to large volumes providing an efficient approach to compute hadronic matrix elements and form factors.

Drach, Vincent [DESY, Zeuthen (Germany); Jansen, Karl [DESY, Zeuthen (Germany); Alexandrou, Constantia [University of Cyprus, Nicosia (Cyprus); Constantinou, Marth [University of Cyprus, Nicosia (Cyprus); Dinter, Simon [DESY, Zeuthen (Germany); Hadjiyiannakou, Kyriakos [University of Cyprus, Nicosia (Cyprus); Renner, Dru B. [JLAB, Newport News, VA (United States)

2014-01-01T23:59:59.000Z

255

Discrete Element Modeling  

SciTech Connect (OSTI)

The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

Morris, J; Johnson, S

2007-12-03T23:59:59.000Z

256

Adaptive Algebraic Multigrid for Finite Element Elliptic Equations with Random Coefficients  

SciTech Connect (OSTI)

This thesis presents a two-grid algorithm based on Smoothed Aggregation Spectral Element Agglomeration Algebraic Multigrid (SA-{rho}AMGe) combined with adaptation. The aim is to build an efficient solver for the linear systems arising from discretization of second-order elliptic partial differential equations (PDEs) with stochastic coefficients. Examples include PDEs that model subsurface flow with random permeability field. During a Markov Chain Monte Carlo (MCMC) simulation process, that draws PDE coefficient samples from a certain distribution, the PDE coefficients change, hence the resulting linear systems to be solved change. At every such step the system (discretized PDE) needs to be solved and the computed solution used to evaluate some functional(s) of interest that then determine if the coefficient sample is acceptable or not. The MCMC process is hence computationally intensive and requires the solvers used to be efficient and fast. This fact that at every step of MCMC the resulting linear system changes, makes an already existing solver built for the old problem perhaps not as efficient for the problem corresponding to the new sampled coefficient. This motivates the main goal of our study, namely, to adapt an already existing solver to handle the problem (with changed coefficient) with the objective to achieve this goal to be faster and more efficient than building a completely new solver from scratch. Our approach utilizes the local element matrices (for the problem with changed coefficients) to build local problems associated with constructed by the method agglomerated elements (a set of subdomains that cover the given computational domain). We solve a generalized eigenproblem for each set in a subspace spanned by the previous local coarse space (used for the old solver) and a vector, component of the error, that the old solver cannot handle. A portion of the spectrum of these local eigen-problems (corresponding to eigenvalues close to zero) form the coarse basis used to define the new two-level method of our interest. We illustrate the performance of this adaptive two-level procedure with a large set of numerical experiments that demonstrate its efficiency over building the solvers from scratch.

Kalchev, D

2012-04-02T23:59:59.000Z

257

Towards the application of the Maximum Entropy Method to finite temperature Upsilon Spectroscopy  

E-Print Network [OSTI]

According to the Narnhofer Thirring Theorem interacting systems at finite temperature cannot be described by particles with a sharp dispersion law. It is therefore mandatory to develop new methods to extract particle masses at finite temperature. The Maximum Entropy method offers a path to obtain the spectral function of a particle correlation function directly. We have implemented the method and tested it with zero temperature Upsilon correlation functions obtained from an NRQCD simulation. Results for different smearing functions are discussed.

M. Oevers; C. Davies; J. Shigemitsu

2000-09-22T23:59:59.000Z

258

A Comparison of Least-Squares Finite Element Models with the Conventional Finite Element Models of Problems in Heat Transfer and Fluid Mechanics  

E-Print Network [OSTI]

disadvantage of classical variational methods is the difficulty in constructing the approximate functions for arbitrary domains. 1.4. Review of Weighted-Residual Methods Weighted-residual methods are those in which we seek approximate solutions using a... functions. The pth order interpolation function is given by )48.2( 1 2 1 1 2 1 221 2 21 T pp npp p kp g g g f f f...

Nellie Rajarova,

2010-07-14T23:59:59.000Z

259

On simple and accurate finite element models for nonlinear bending analysis of beams and plates  

E-Print Network [OSTI]

that rotates with the element and with respect to which the standard linear engineering relations between strains and internal forces are valid. The element is based on Lagrange interpolation of the axial displacement, Hermite cubic interpolation...

Urthaler Lapeira, Yetzirah Yksya

2007-09-17T23:59:59.000Z

260

Method and apparatus for diagnosing breached fuel elements  

DOE Patents [OSTI]

The invention provides an apparatus and method for diagnosing breached fuel elements in a nuclear reactor. A detection system measures the activity of isotopes from the cover gas in the reactor. A data acquisition and processing system monitors the detection system and corrects for the effects of the cover-gas clean up system on the measured activity and further calculates the derivative curve of the corrected activity as a function of time. A plotting system graphs the derivative curve, which represents the instantaneous release rate of fission gas from a breached fuel element. 8 figs.

Gross, K.C.; Lambert, J.D.B.; Nomura, S.

1987-03-02T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

A 3D finite-element modelling investigation into optimal survey parameters and direct imaging for marine controlled-source electromagnetic surveys  

E-Print Network [OSTI]

Relatively little is known about marine controlled-source electromagnetic surveys (MCSEM) used to detect hydrocarbon reservoirs. Typical MCSEM require the use of inversion to generate a model of the subsurface. We utilize a 3D finite-element forward...

Lau, Ryan

2007-09-17T23:59:59.000Z

262

Rutting Performance of Airport Hot-Mix Asphalt Characterized by Laboratory Performance Testing, Full-Scale Accelerated Pavement Testing, and Finite Element Modeling  

E-Print Network [OSTI]

potential laboratory tests, (b) comparisons of laboratory tests results to full-scale accelerated pavement test results, and (c) analyses of results from finite element simulations. The laboratory study evaluated of the repeated load test, the static creep...

Rushing, John Ford

2014-04-25T23:59:59.000Z

263

A Design-Oriented Framework to Determine the Parasitic Parameters of High Frequency Magnetics in Switching Power Supplies using Finite Element Analysis Techniques  

E-Print Network [OSTI]

A DESIGN-ORIENTED FRAMEWORK TO DETERMINE THE PARASITIC PARAMETERS OF HIGH FREQUENCY MAGNETICS IN SWITCING POWER SUPPLIES USING FINITE ELEMENT ANALYSIS TECHNIQUES A Thesis by MOHAMMAD BAGHER SHADMAND Submitted to the Office... to Determine the Parasitic Parameters of High Frequency Magnetics in Switching Power Supplies using Finite Element Analysis Techniques Copyright 2012 Mohammad Bagher Shadmand A DESIGN-ORIENTED FRAMEWORK TO DETERMINE THE PARASITIC PARAMETERS OF HIGH...

Shadmand, Mohammad

2012-07-16T23:59:59.000Z

264

Key Elements of and Materials Performance Targets for Highly Insulating Window Frames  

E-Print Network [OSTI]

finite-element method (FEM) program, THERM (Finlayson et al. , 1998), to solve the conductive heat-transfer

Gustavsen, Arild

2012-01-01T23:59:59.000Z

265

Method for measuring recovery of catalytic elements from fuel cells  

DOE Patents [OSTI]

A method is provided for measuring the concentration of a catalytic clement in a fuel cell powder. The method includes depositing on a porous substrate at least one layer of a powder mixture comprising the fuel cell powder and an internal standard material, ablating a sample of the powder mixture using a laser, and vaporizing the sample using an inductively coupled plasma. A normalized concentration of catalytic element in the sample is determined by quantifying the intensity of a first signal correlated to the amount of catalytic element in the sample, quantifying the intensity of a second signal correlated to the amount of internal standard material in the sample, and using a ratio of the first signal intensity to the second signal intensity to cancel out the effects of sample size.

Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley, NJ)

2011-03-08T23:59:59.000Z

266

Rotordynamic analysis with shell elements for the transfer matrix method  

E-Print Network [OSTI]

Committee) Al B. elazzo1o (Member) John T. Tielki g (Member) Michael J. Rabins (Head of Department) August 1989 111 ABSTRACT Rotordynamic Analysis with Shell Elements for the Transi'er Matrix Method. (August 1989) Edward Anthony L'Antigua, B. M... Varying Bending Load with (-') = . 01, and Varying ( ? ) ratio. Table 2. Nondimensional Flexibilities (aEv ) for Cylindrical Sections (8 = 0) with Varying ( ? ) and (?-) Ratios. Table 3. Nondimensional Flexibilities (bEr = oEr ) for Cylindrical...

L'Antigua, Edward Anthony

1989-01-01T23:59:59.000Z

267

Method for detection of antibodies for metallic elements  

DOE Patents [OSTI]

An apparatus and method for detecting antibodies specific to non-protein antigens. The apparatus is an immunological plate containing a plurality of plastic projections coated with a non-protein material. Assays utilizing the plate are capable of stabilizing the non-protein antigens with detection levels for antibodies specific to the antigens on a nanogram level. A screening assay with the apparatus allows for early detection of exposure to non-protein materials. Specifically metallic elements are detected.

Barrick, Charles W. (Golden, CO); Clarke, Sara M. (Larkspur, CO); Nordin, Carl W. (Golden, CO)

1993-11-30T23:59:59.000Z

268

Method for detection of antibodies for metallic elements  

DOE Patents [OSTI]

An apparatus and method for detecting antibodies specific to non-protein antigens. The apparatus is an immunological plate containing a plurality of plastic projections coated with a non-protein material. Assays utilizing the plate are capable of stabilizing the non-protein antigens with detection levels for antibodies specific to the antigens on a nanogram level. A screening assay with the apparatus allows for early detection of exposure to non-protein materials. Specifically metallic elements are detected. 10 figures.

Barrick, C.W.; Clarke, S.M.; Nordin, C.W.

1993-11-30T23:59:59.000Z

269

Brake rotor design and comparison using finite element analysis : an investigation in topology optimization  

E-Print Network [OSTI]

An Introduction to the Conjugate Gradient Method Without thedescent method and the conjugate gradient method. The onlymethod and the conjugate gradient method can be found in

Domond, Kenneth

2010-01-01T23:59:59.000Z

270

Efficient numerical methods for capacitance extraction based on boundary element method  

E-Print Network [OSTI]

algorithms based on boundary element methods (BEM) and to compute the capacitance extraction in the presence of floating dummy conductors. We propose the PHiCap algorithm, which is based on a hierarchical refinement algorithm and the wavelet transform. Unlike...

Yan, Shu

2006-04-12T23:59:59.000Z

271

AN UPWIND FINITE-DIFFERENCE METHOD FOR TOTAL ...  

E-Print Network [OSTI]

Nuclear Sci., 39 (1992), pp. 11441152. 18 ... Total variation minimization and a class of binary mrf models, in Energy Minimization. Methods in Computer Vision...

2010-09-17T23:59:59.000Z

272

Incorporation and modification of a shear deformable finite element into MARC  

E-Print Network [OSTI]

Calculation. Failure Progression Prediction. 2 4 6 8 9 10 QHD40 ELEMENT FUNDAMENTALS . . Review of QHD40 Element Displacement Field. Constitutive Relations. Interlaminar Stresses. 12 12 15 16 TAPER FORMULATION. 20 Taper Capabilities... 42 Cantilevered tapered plate . Page 65 43 Cross-sectional view of tapered laminate 44 Cantilevered plate with Sxg mesh and boundary conditions . . . . . 68 45 Tapered vs. flat plate deflection. . 69 46 Tapered plate transverse displacement. 47...

Hofman, Brad Burdell

2012-06-07T23:59:59.000Z

273

THE DENSITY OF STATES METHOD AT FINITE CHEMICAL POTENTIAL.  

SciTech Connect (OSTI)

We study the density of states method to explore the phase diagram of the chiral transition on the temperature and quark chemical potential plane. Four quark flavors are used in the analysis. Though the method is quite expensive small lattices show an indication for a triple-point connecting three different phases on the phase diagram.

SCHMIDT, C.; FODOR, Z.; KATZ, S.

2005-08-02T23:59:59.000Z

274

CIP/multi-moment finite volume method with arbitrary order of accuracy  

E-Print Network [OSTI]

This paper presents a general formulation of the CIP/multi-moment finite volume method (CIP/MM FVM) for arbitrary order of accuracy. Reconstruction up to arbitrary order can be built on single cell by adding extra derivative moments at the cell boundary. The volume integrated average (VIA) is updated via a flux-form finite volume formulation, whereas the point-based derivative moments are computed as local derivative Riemann problems by either direct interpolation or approximate Riemann solvers.

Xiao, Feng

2012-01-01T23:59:59.000Z

275

Application of the vortex-box method to the unsteady incompressible flow over finite wings  

E-Print Network [OSTI]

APPLICATION OP THE VORTEX-BOX MRTHOD TO THE UNSTEADT INCOMPRESSIBLE FLOW OVER FINITE WINGS A Thesis by CHARLES UPTON SONCRANT Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1973 Major Subject: Aerospace Engineering APPLICATION OF THE VORTEX-BOX METHOD TO THE UNSTEADY INCOMPRESSIBLE FLOW OVER FINITE WINGS A Thesis by CHARLES UPTON SONCRANT Approved as to style and content by: (Chairman...

Soncrant, Charles Upton

2012-06-07T23:59:59.000Z

276

REMARKS ON THE MAXIMUM ENTROPY METHOD APPLIED TO FINITE TEMPERATURE LATTICE QCD.  

SciTech Connect (OSTI)

We make remarks on the Maximum Entropy Method (MEM) for studies of the spectral function of hadronic correlators in finite temperature lattice QCD. We discuss the virtues and subtlety of MEM in the cases that one does not have enough number of data points such as at finite temperature. Taking these points into account, we suggest several tests which one should examine to keep the reliability for the results, and also apply them using mock and lattice QCD data.

UMEDA, T.; MATSUFURU, H.

2005-07-25T23:59:59.000Z

277

Remarks on the Maximum Entropy Method applied to finite temperature lattice QCD  

E-Print Network [OSTI]

We make remarks on the Maximum Entropy Method (MEM) for studies of the spectral function of hadronic correlators in finite temperature lattice QCD. We discuss the virtues and subtlety of MEM in the cases that one does not have enough number of data points such as at finite temperature. Taking these points into account, we suggest several tests which one should examine to keep the reliability for the results, and also apply them using mock and lattice QCD data.

Takashi Umeda; Hideo Matsufuru

2005-10-05T23:59:59.000Z

278

The Distinct Element Method - Application to Structures in Jointed Rock  

SciTech Connect (OSTI)

The Distinct Element Method (DEM) is a meshfree method with applications to rock mechanics, mining sciences, simulations of nuclear repositories, and the stability of underground structures. Continuum mesh-based methods have been applied successfully to many problems in geophysics. Even if the geology includes fractures and faults, when sufficiently large length scales are considered a continuum approximation may be sufficient. However, a large class of problems exist where individual rock joints must be taken into account. This includes problems where the structures of interest have sizes comparable with the block size. In addition, it is possible that while the structure may experience loads which do no measurable damage to individual blocks, some joints may fail. This may launch smaller blocks as dangerous projectiles or even cause total failure of a tunnel. Traditional grid-based continuum approaches are wholly unsuited to this class of problem. It is possible to introduce discontinuities or slide lines into existing grid-based methods, however, such limited approaches can break down when new contacts form between blocks. The distinct element method (DEM) is an alternative, meshfree approach. The DEM can directly approximate the block structure of the jointed rock using arbitrary polyhedra. Using this approach, preexisting joints are readily incorporated into the DEM model. In addition, the method detects all new contacts between blocks resulting from relative block motion. We will describe the background of the DEM and review previous application of the DEM to geophysical problems. Finally we present preliminary results from a investigation into the stability of underground structures subjected to dynamic loading.

Morris, J.P.; Glen, L.; Blair, S.; Heuze, F.

2001-11-30T23:59:59.000Z

279

A Mortar Mimetic Finite Difference Method on NonMatching Grids  

E-Print Network [OSTI]

, and Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, TX 78712, U intersecting at each vertex [15]. The methods has also been extended to locally refined meshes with hanging for the normal velocities in MFD methods on h 2 ­uniform quadrilateral meshes was established. Mixed finite

Berndt, Markus

280

Wave propagation across acoustic / Biot's media: a finite-difference method  

E-Print Network [OSTI]

Wave propagation across acoustic / Biot's media: a finite-difference method Guillaume Chiavassa1 Marseille, France. Abstract. Numerical methods are developed to simulate the wave propagation in het- erogeneous 2D fluid / poroelastic media. Wave propagation is described by the usual acoustics equations (in

Boyer, Edmond

Note: This page contains sample records for the topic "finite element method" 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

Mixed finite element discretization of a model for organic pollution in waters  

E-Print Network [OSTI]

of the DO and its flux at the boundary. Currently, no oxygen flux is generated by the environmental medium the Biochemical Oxygen Demand and Dissolved Oxygen to which dispersion terms are added. In this work, we propose. The central element of such problems is the oxygen. The main tracers currently used are the density b

Paris-Sud XI, Université de

282

Numerical study on transient heat transfer under soil with plastic mulch in agriculture applications using a nonlinear finite element model  

E-Print Network [OSTI]

In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.

De Castro, Carlos Armando

2011-01-01T23:59:59.000Z

283

Higher-Order, Space-Time Adaptive Finite Volume Methods: Algorithms, Analysis and Applications  

SciTech Connect (OSTI)

The four main goals outlined in the proposal for this project were: 1. Investigate the use of higher-order (in space and time) finite-volume methods for fluid flow problems. 2. Explore the embedding of iterative temporal methods within traditional block-structured AMR algorithms. 3. Develop parallel in time methods for ODEs and PDEs. 4. Work collaboratively with the Center for Computational Sciences and Engineering (CCSE) at Lawrence Berkeley National Lab towards incorporating new algorithms within existing DOE application codes.

Minion, Michael

2014-04-29T23:59:59.000Z

284

Anisotropic mesh adaptation for solution of finite element problems using hierarchical edge-based error estimates  

SciTech Connect (OSTI)

We present a new technology for generating meshes minimizing the interpolation and discretization errors or their gradients. The key element of this methodology is construction of a space metric from edge-based error estimates. For a mesh with N{sub h} triangles, the error is proportional to N{sub h}{sup -1} and the gradient of error is proportional to N{sub h}{sup -1/2} which are optimal asymptotics. The methodology is verified with numerical experiments.

Lipnikov, Konstantin [Los Alamos National Laboratory; Agouzal, Abdellatif [UNIV DE LYON; Vassilevski, Yuri [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

285

Finite-Volume-Particle Methods for Models of Transport of Pollutant in Shallow Water  

E-Print Network [OSTI]

Finite-Volume-Particle Methods for Models of Transport of Pollutant in Shallow Water Alina Chertock of shallow water equations and the pollutant propagation is described by a transport equation. The idea and the pollution computations: the shallow water equations are numerically integrated using a #12;nite- volume

Kurganov, Alexander

286

FINITE VOLUME METHODS APPLIED TO THE COMPUTATIONAL MODELLING OF WELDING PHENOMENA  

E-Print Network [OSTI]

1 FINITE VOLUME METHODS APPLIED TO THE COMPUTATIONAL MODELLING OF WELDING PHENOMENA Gareth A.Taylor@brunel.ac.uk ABSTRACT This paper presents the computational modelling of welding phenomena within a versatile numerical) and Computational Solid Mechanics (CSM). With regard to the CFD modelling of the weld pool fluid dynamics, heat

Taylor, Gary

287

Finite-difference time domain method for light scattering by small ice  

E-Print Network [OSTI]

can be employed to produce the scattering and ab- sorption characteristics of hexagonal ice particlesFinite-difference time domain method for light scattering by small ice crystals in three for the solution of light scattering by nonspherical particles has been developed for small ice crystals

Liou, K. N.

288

Finite Difference Methods for the Heat Equation MATH 418, PDE LAB Spring 2013  

E-Print Network [OSTI]

Finite Difference Methods for the Heat Equation MATH 418, PDE LAB Spring 2013 Lab #5 We seek numerical solutions of the heat equation u t = c2 2 u x2 , 0 0 (1) with boundary conditions u(0) Here x = L/(N + 1). The collection of points (4), (5) is called the computational grid. The matrix-grid

Bardsley, John

289

Power and efficiency limits for internal combustion engines via methods of finite-time thermodynamics  

E-Print Network [OSTI]

Power and efficiency limits for internal combustion engines via methods of finite publication 17 June 1993) Analytical expressionsfor the upper bounds of power and efficiency of an internal and expensiveto compute and analyze.2If we are interestedin maximum power output or in maximum effi- ciency

Berry, R. Stephen

290

Superconvergence of finite element approximations by a computer-based approach  

E-Print Network [OSTI]

. Superconvcrgence poi?ts I'or I, hc & lass of "harmonic" solutious of the cquatio?s of pla?c elasl i& i ty: Cubi& i& n?dipitv square elements The superconvergence points arc le& atcd at the intersection of thc contours C a?' (P; f, T), i = 1, . . . , 4... of &he mat('ri;&I orl, l&ot ropy. Sup( r(o?v& rgcuce points fol the r& curl]po?eut of thc Ih&s, &I&('u) I'o&. tl&& ?lais of "harmonic" solutions of th&. cquatio? ol' or&i&olropi& h( &I, -&. ond?ction: Cubic serendipity ele&?cnts. /cro-co?to?rs a?d s...

Gangaraj, Srihari Kumar

1994-01-01T23:59:59.000Z

291

Least squares based finite element formulations and their applications in fluid mechanics  

E-Print Network [OSTI]

are proposed, implemented in a computational scheme, and evaluated in this study. The continuity equation is treated as a constraint on the velocity field and the constraint is enforced using the penalty method. These penalty based formulations produce accurate...

Prabhakar, Vivek

2009-05-15T23:59:59.000Z

292

Stability Analysis for a Saline Boundary Layer Formed by Uniform Up ow Using Finite Elements  

E-Print Network [OSTI]

density in the deeper underground and high salt water density at the boundary layer), gravitation plays and Darcy's law. In this report we #12;rst give an overview of semi-analytical methods to analyse

Eindhoven, Technische Universiteit

293

Finite Element Modelling of the Sawing of DC Cast AA2024 Aluminium Alloy Slabs  

SciTech Connect (OSTI)

In the semi-continuous casting of large cross-section rolling sheet ingots of high-strength aluminum alloys (2xxx and 7xxx series), the control of the residual (internal) stresses generated by the non-uniform cooling becomes a necessity. These stresses must be relieved by a thermal treatment before the head and foot of the ingot can be cut. Otherwise, the saw can be caught owing to compressive stresses or cut parts may be ejected thus injuring people or damaging equipment. These high added-value ingots need to be produced in secure conditions. Moreover, a better control of the sawing procedure could allow the suppression of the thermal treatment and therefore save time and energy. By studying the stress build-up during casting and the stress relief during sawing, key parameters for the control and optimization of the processing steps, can be derived. To do so, the direct chill (DC) casting of the AA2024 alloy is modeled with ABAQUS 6.5 with special attention to the thermo-mechanical properties of the alloy. The sawing operation is then simulated by removing mesh elements so as to reproduce the progression of the saw in the ingot. Preliminary results showing the stress relief during sawing accompanied by the risk of saw blocking due to compression or initiating a crack ahead of the saw, are analyzed with an approach based on the rate of strain energy release.

Drezet, J.-M. [Computational Materials Laboratory, School of Engineering, Ecole Polytechnique Federale de Lausanne, Station 12, CH-1015 Lausanne (Switzerland); Ludwig, O. [Calcom-ESI SA, PSE-A, CH-1015 Lausanne (Switzerland); Heinrich, B. [Alcan Aluminium Valais SA, CH3960 Sierre (Switzerland)

2007-04-07T23:59:59.000Z

294

Finite element study of multi-modal vibration damping for thermal barrier coating applications  

E-Print Network [OSTI]

barriers for gas turbine blades, there is a growing interest in devel- oping multifunctional coatings methods is critical in many tech- nologies and especially so for gas turbine engines since many the spinning up of the turbine to avoid resonances. One of the advances made in gas turbine technologies, has

295

Finite Elements for a Beam System With Nonlinear Contact Under Periodic Excitation  

E-Print Network [OSTI]

. Rousselet Abstract Solar arrays are structures which are connected to satellites; during launch, they are in a folded position and submitted to high vibrations. In order to save mass, the flexibility of the panels investigation of nonlinear normal mode (NNM) can be a new method to describe nonlinear behaviors, this work

Boyer, Edmond

296

High-order Time-stepping for Galerkin and Collocation Methods Based on Component-wise  

E-Print Network [OSTI]

to other spatial discretiza- tions, such as finite elements and meshless methods, extends the applicability--spectral methods, finite elements, meshless methods, Gaussian quadrature, block Lanczos I. INTRODUCTION The rapid with existing methods that are applicable to such problems, including finite element methods and meshless

Lambers, James

297

Finite element simulation of laser spot welding A. De, S. K. Maiti, C. A. Walsh and H. K. D. H. Bhadeshia  

E-Print Network [OSTI]

Finite element simulation of laser spot welding A. De, S. K. Maiti, C. A. Walsh and H. K. D. H laser spot welding, taking into account the temperature dependence of the physical properties and latent formation during laser spot welding, although the `double ellipsoidal' representation requires an a priori

Cambridge, University of

298

Charmonium spectral functions with the variational method in zero and finite temperature lattice QCD  

SciTech Connect (OSTI)

We propose a method to evaluate spectral functions on the lattice based on a variational method. On a lattice with a finite spatial extent, spectral functions consist of discrete spectra only. Adopting a variational method, we calculate the locations and the heights of spectral functions at low-lying discrete spectra. We first test the method in the case of analytically solvable free Wilson quarks at zero and finite temperatures and confirm that the method well reproduces the analytic results for low-lying spectra. We find that we can systematically improve the results by increasing the number of trial states. We then apply the method to calculate the charmonium spectral functions for S and P-wave states at zero-temperature in quenched QCD and compare the results with those obtained using the conventional maximum entropy method (MEM). The results for the ground state are consistent with the location and the area of the first peak in spectral functions from the MEM, while the variational method leads to a mass which is closer to the experimental value for the first excited state. We also investigate the temperature dependence of the spectral functions for S-wave states below and above T{sub c}. We obtain no clear evidences for dissociation of J/{psi} and {eta}{sub c} up to 1.4T{sub c}.

Ohno, H.; Kanaya, K.; Saito, H. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Aoki, S. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Ejiri, S. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Maezawa, Y. [Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Umeda, T. [Graduate School of Education, Hiroshima University, Hiroshima 739-8524 (Japan)

2011-11-01T23:59:59.000Z

299

Charmonium spectral functions with the variational method in zero and finite temperature lattice QCD  

SciTech Connect (OSTI)

We propose a method to evaluate spectral functions on the lattice based on a variational method. On a lattice with a finite spatial extent, spectral functions consist of discrete spectra only. Adopting a variational method, we calculate the locations and the heights of spectral functions at low-lying discrete spectra. We first test the method in the case of analytically solvable free Wilson quarks at zero and finite temperatures and confirm that the method well reproduces the analytic results for low-lying spectra. We find that we can systematically improve the results by increasing the number of trial states. We then apply the method to calculate the charmonium spectral functions for S and P-wave states at zero-temperature in quenched QCD and compare the results with those obtained using the conventional maximum entropy method (MEM). The results for the ground state are consistent with the location and the area of the first peak in spectral functions from the MEM, while the variational method leads to a mass which is closer to the experimental value for the first excited state. We also investigate the temperature dependence of the spectral functions for S-wave states below and above T{sub c}. We obtain no clear evidences for dissociation of J/{psi} and {eta}{sub c} up to 1.4 T{sub c}.

Maezawa Y.; Ohno, H.; Ejiri, S.; Kanaya, K.; Saito, H.; Umeda, T.

2011-11-14T23:59:59.000Z

300

Improved detection of rough defects for ultrasonic NDE inspections based on finite element modeling of elastic wave scattering  

SciTech Connect (OSTI)

Defects which posses rough surfaces greatly affect ultrasonic wave scattering behaviour, often reducing the magnitude of reflected signals. Ultrasonic inspections rely upon this response for detecting and sizing flaws. For safety critical components reliable characterisation is crucial. Therefore, providing an accurate means to predict reductions in signal amplitude is essential. An extension of Kirchhoff theory has formed the basis for the UK power industry inspection justifications. However, it is widely recognised that these predictions are pessimistic owing to analytical approximations. A numerical full field modelling approach does not fall victim to such limitations. Here, a Finite Element model is used to aid in setting a non-conservative reporting threshold during the inspection of a large pressure vessel forging that might contain embedded rough defects. The ultrasonic response from multiple rough surfaces defined by the same statistical class is calculated for normal incident compression waves. The approach is validated by comparing coherent scattering with predictions made by Kirchhoff theory. At lower levels of roughness excellent agreement is observed, whilst higher values confirm the pessimism of Kirchhoff theory. Furthermore, the mean amplitude in the specular direction is calculated. This represents the information obtained during an inspection, indicating that reductions due to increasing roughness are significantly less than the coherent component currently being used.

Pettit, J. R. [Rolls-Royce Nuclear, PO BOX 2000, Derby, UK, DE21 7XX and Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Walker, A. [Rolls-Royce Nuclear, PO BOX 2000, Derby DE21 7XX (United Kingdom); Lowe, M. J. S. [Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

2014-02-18T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Finite element analyses of continuous filament ties for masonry applications:final report for the Arquin Corporation.  

SciTech Connect (OSTI)

Finite-element analyses were performed to simulate the response of a hypothetical masonry shear wall with and without continuous filament ties to various lateral loads. The loads represented three different scenarios: (1) 100 mph wind, (2) explosive attack, and (3) an earthquake. In addition, a static loading analysis and cost comparison were performed to evaluate optimal materials and designs for the spacers affixed to the filaments. Results showed that polypropylene, ABS, and polyethylene (high density) were suitable materials for the spacers based on performance and cost, and the short T-spacer design was optimal based on its performance and functionality. Results of the shear-wall loading simulations revealed that simulated walls with the continuous filament ties yielded factors of safety that were at least ten times greater than those without the ties. In the explosive attack simulation (100 psi), the simulated wall without the ties failed (minimum factor of safety was less than one), but the simulated wall with the ties yielded a minimum factor of safety greater than one. Simulations of the walls subject to lateral loads caused by 100 mph winds (0.2 psi) and seismic events with a peak ground acceleration of 1 ''g'' (0.66 psi) yielded no failures with or without the ties. Simulations of wall displacement during the seismic scenarios showed that the wall with the ties resulted in a maximum displacement that was 20% less than the wall without the ties.

Quinones, Armando (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei

2006-06-01T23:59:59.000Z

302

Hp-spectral Methods for Structural Mechanics and Fluid Dynamics Problems  

E-Print Network [OSTI]

based finite element methods with the Penalty finite element method are presented for modelling porous media flow problems. Finally, we explore applications to some CFD problems namely, the flow past a cylinder and forward facing step....

Ranjan, Rakesh

2011-08-08T23:59:59.000Z

303

Physical finite elements  

E-Print Network [OSTI]

Engineering with digital materials, by discretely and reversibly assembling structure and function from a mass-produced construction kit of parts, is indeed an exciting vision. The ability to decouple conventionally linked ...

Calisch, Samuel Eli

2014-01-01T23:59:59.000Z

304

System and method for reproducibly mounting an optical element  

DOE Patents [OSTI]

The present invention provides a two-piece apparatus for holding and aligning the MEMS deformable mirror. The two-piece apparatus comprises a holding plate for fixedly holding an adaptive optics element in an overall optical system and a base spatially fixed with respect to the optical system and adapted for mounting and containing the holding plate. The invention further relates to a means for configuring the holding plate through adjustments to each of a number of off-set pads touching each of three orthogonal plane surfaces on the base, wherein through the adjustments the orientation of the holding plate, and the adaptive optics element attached thereto, can be aligned with respect to the optical system with six degrees of freedom when aligning the plane surface of the optical element. The mounting system thus described also enables an operator to repeatedly remove and restore the adaptive element in the optical system without the need to realign the system once that element has been aligned.

Eisenbies, Stephen; Haney, Steven

2005-05-31T23:59:59.000Z

305

Interfacial temperature measurements, high-speed visualization and finite-element simulations of droplet impact and evaporation on a solid surface  

E-Print Network [OSTI]

The objective of this work is to investigate the coupling of fluid dynamics, heat transfer and mass transfer during the impact and evaporation of droplets on a heated solid substrate. A laser-based thermoreflectance method is used to measure the temperature at the solid-liquid interface, with a time and space resolution of 100 {\\mu}s and 20 {\\mu}m, respectively. Isopropanol droplets with micro- and nanoliter volumes are considered. A finite-element model is used to simulate the transient fluid dynamics and heat transfer during the droplet deposition process, considering the dynamics of wetting as well as Laplace and Marangoni stresses on the liquid-gas boundary. For cases involving evaporation, the diffusion of vapor in the atmosphere is solved numerically, providing an exact boundary condition for the evaporative flux at the droplet-air interface. High-speed visualizations are performed to provide matching parameters for the wetting model used in the simulations. Numerical and experimental results are compar...

Bhardwaj, Rajneesh; Attinger, Daniel

2010-01-01T23:59:59.000Z

306

Method for recovering catalytic elements from fuel cell membrane electrode assemblies  

DOE Patents [OSTI]

A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley Heights, NJ); Heinz, Robert (Ludwigshafen, DE)

2012-06-26T23:59:59.000Z

307

Modeling the steady-state ISV (in situ vitrification) process: A 3-D finite element analysis of coupled thermal-electric fields  

SciTech Connect (OSTI)

Steady-state modeling considerations for simulating the in situ vitrification (ISV) process are documented based upon the finite element numerical approach. Recommendations regarding boundary condition specifications and mesh discretization are presented. The effects of several parameters on the ISV process response are calculated and the results discussed. The parameters investigated include: (1) electrode depth, (2) ambient temperature, (3) supplied current, (4) electrical conductivity, (5) electrode separation, and (6) soil/waste characterization. 13 refs., 29 figs., 1 tab.

Langerman, M.A.

1990-09-01T23:59:59.000Z

308

Charmonium spectra at finite temperature from QCD sum rules with the maximum entropy method  

E-Print Network [OSTI]

Charmonia spectral functions at finite temperature are studied using QCD sum rules in combination with the maximum entropy method. This approach enables us to directly obtain the spectral function from the sum rules, without having to introduce any specific assumption about its functional form. As a result, it is found that while J/psi and eta_c manifest themselves as significant peaks in the spectral function below the deconfinement temperature T_c, they quickly dissolve into the continuum and almost completely disappear at temperatures between 1.0 T_c and 1.1 T_c.

Philipp Gubler; Kenji Morita; Makoto Oka

2011-08-30T23:59:59.000Z

309

Security analysis of the decoy method with the Bennett-Brassard 1984 protocol for finite key lengths  

E-Print Network [OSTI]

This paper provides a formula for the sacrifice bit-length for privacy amplification with the Bennett-Brassard 1984 protocol for finite key lengths when we employ the decoy method. Using the formula, we can guarantee the security parameter for realizable quantum key distribution system. The key generation rates with finite key lengths are numerically evaluated. The proposed method improves the existing key generation rate even in the asymptotic setting.

Masahito Hayashi; Ryota Nakayama

2013-11-19T23:59:59.000Z

310

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS  

E-Print Network [OSTI]

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS JASON FULMAN Abstract. Combining Stein's method with heat kernel techniques, we show that the trace of the jth power There is a large literature on the traces of powers of random elements of compact Lie groups. One of the earliest

Fulman, Jason

311

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS  

E-Print Network [OSTI]

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS JASON FULMAN Abstract. Combining Stein's method with heat kernel techniques, we show that the trace of the jth power on the traces of powers of random elements of compact Lie groups. One of the earliest results is due to Diaconis

Fulman, Jason

312

An advanced 3D boundary element method for characterizations of composite materials  

E-Print Network [OSTI]

An advanced 3D boundary element method for characterizations of composite materials X.L. Chena , Y developments in the modeling of composite materials using the boundary element method (BEM) are presented in dealing with nearly-singular integrals, which arise in the BEM modeling of composite materials

Liu, Yijun

313

FINITE GROUPS WITH TWO CONJUGACY CLASSES OF p-ELEMENTS AND RELATED QUESTIONS FOR p-BLOCKS  

E-Print Network [OSTI]

K¨ULSHAMMER, GABRIEL NAVARRO, BENJAMIN SAMBALE, AND PHAM HUU TIEP Abstract. We prove that a finite:01:25 BST Version 2 - Submitted to BLMS #12;2 K¨ULSHAMMER, NAVARRO, SAMBALE, AND TIEP Theorem A can

314

AN EFFICIENT AND STABLE SPECTRAL-ELEMENT METHOD FOR ...  

E-Print Network [OSTI]

harmonic sound waves in a homogeneous compressible fluid by an obstacle is de- veloped in this ... sented to show the accuracy and stability of the method. 1.

2013-08-08T23:59:59.000Z

315

Methods developed for detecting hazardous elements in produced gas  

SciTech Connect (OSTI)

The Institute of Gas Technology, Des Plaines, Ill. has been developing sampling and analytical methods to detect in natural gas various trace constituents that may pose health, safety, or operational risks. The constituents of interest include paraffinic and aromatic hydrocarbons, H[sub 2]S, organic sulfur compounds, arsenic, mercury, radon, and others. Better sampling and analytical techniques for produced natural gas, similar to those developed by IGT for processed gas, will enhance producers and processors' abilities to monitor undesirable constituents in raw gas streams and improve their clean-up processes. The methods developed at IGT were modifications of air sampling and analytical methods that are commonly used for air toxic substances. These monitoring methods, when applied to natural gas, present special challenges because gas has a much more complex matrix than the air. Methods for the analysis of the following are discussed: arsenic, mercury, radon, sulfur compounds, hydrocarbons, and aromatics including BTEX and PAHs.

Chao, S.; Attari, A. (Inst. of Gas Technology, Des Plaines, IL (United States))

1995-01-16T23:59:59.000Z

316

Methods for making a porous nuclear fuel element  

DOE Patents [OSTI]

Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

Youchison, Dennis L; Williams, Brian E; Benander, Robert E

2014-12-30T23:59:59.000Z

317

Boundary Element Method for Internal Axisymmetric Flow Dr. Alexander Gokhman  

E-Print Network [OSTI]

to the practical cases of axisymmetric flow in Francis and Kaplan turbine passages with conical and of the method to the computation of flow in turbomachines of Kaplan and Francis types. 1 Introduction

Gokhman, Dmitry

318

A semi-implicit finite element method for viscous lipidic membranes Diego S. Rodriguesa  

E-Print Network [OSTI]

(per6 unit area) is a function of the local curvature alone[2, 3]. Such an energy density is typical7), and an analogous strategy is used to filter out rigid-body motions. The nodal positions are updated in a Lagrangian manner according to the velocity solution at each time step. An automatic remeshing strategy maintains

Buscaglia, Gustavo C.

319

STATE OF THE ART IN THE h-p VERSION OF THE FINITE ELEMENT METHOD  

E-Print Network [OSTI]

on polygonal domain by commercial codes MSC/PROBE, PHLEX, and MECHANICAL, etc., and research code STRIPE

Guo, Benqi

320

The h-p Version of Finite Element Method in R3 Theory and Algorithm  

E-Print Network [OSTI]

the industry of commercialFEM codes, such as MSC/PROBE, PHLEX, MECHANICAL, STREE CHECK, and research code

Guo, Benqi

Note: This page contains sample records for the topic "finite element method" 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

Conservative Flux Recovery from the Q1 Conforming Finite Element Method on  

E-Print Network [OSTI]

University, Bowling Green, Ohio 43403-0221 2 Department of Mathematics and Statistics, Bowling Green State State University, Bowling Green, OH 43403-0221 (e-mail: chou@bgnet.bgsu.edu) Contract grant sponsor-Hsiang Chou,1 Songnian He,2 Wen-Wei Lin3 1 Department of Mathematics and Statistics, Bowling Green State

Lin, Wen-Wei

322

Error Estimates and Superconvergence for Covolume or Finite Volume Element Methods  

E-Print Network [OSTI]

-Hsiang Chou,1 Do Y. Kwak,2 Qian Li3 1 Department of Mathematics and Statistics, Bowling Green State University, Department of Mathematics and Statistics, Bowling Green State University, Bowling Green, OH 43403-0221 (e, Bowling Green, Ohio 43403-0221 2 Department of Mathematics and Statistics, Korea Advanced Institute

Chou, So-Hsiang

323

Conservative Flux Recovery from the Q1 Conforming Finite Element Method on  

E-Print Network [OSTI]

--Hsiang Chou Department of Mathematics and Statistics Bowling Green State University Bowling Green, OH 43403­0221, email:chou@bgnet.bgsu.edu 1 Songnian He Department of Mathematics and Statistics Bowling Green State University Bowling Green, OH 43403­0221 Wen­Wei Lin Department of Mathematics National Tsing­Hua University

Chou, So-Hsiang

324

Dynamic analysis of shells of revolution submerged in an acoustic medium by the finite element method  

E-Print Network [OSTI]

matrix due to radiated pressure modulus of elasticity linear mid-surface strain for the shell generalized applied load matrix shear modulus generalized radiated pressure matrix assembled equivalent nodal loads due to radiated pressure weight... and the shell material are 0 037 and 0 289 slug per cubic inch, respectively, and the speed of sound in water is taken as 4700 feet per second. This corresponds to a steel shell in sea water. An in ternal pressure of 50 p. s. i. is assumed. The nodal forces...

Ng, Chi Kin

1978-01-01T23:59:59.000Z

325

Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation  

E-Print Network [OSTI]

= 4k2. 6.3. Advection-diffusion problems. An advection-diffusion problem is con- sidered on the domain ? = (?1, 1)2, with = 0, a = (ex(y cos y + sin y), exy sin y) and for various values of ?. The source term f is chosen such that equation (6...

Wells, G N

2009-10-29T23:59:59.000Z

326

Studies on Nano-Indentation of Polymeric Thin Films Using Finite Element Methods  

E-Print Network [OSTI]

In this paper, the numerical simulation for nano-indentation is performed to measure time-dependent behavior of polymeric films. The possibility to extract the relaxed shear modulus of the polymer is evaluated using a rigid ...

Shen, Xiaojun

327

A Variational Finite Element Method for Source Inversion for Convective-Diffusive Transport  

E-Print Network [OSTI]

variation regularization for discontinuous sources, the invertibility of the source as the transport becomes's Scientific Discovery Through Advanced Computing (SciDAC) program through the Teras- cale Optimal PDE hope to recover components of the source function that are more oscillatory than dictated

Ghattas, Omar

328

Detecting and modeling cement failure in high pressure/ high temperature wells using finite-element method  

E-Print Network [OSTI]

conditions and are investigated simultaneously to more accurately predict cement failure. The results of this study show the relevant dependency of stress principles with temperature and pressure. These results clarify the deformation caused by any...

Shahri, Mehdi Abbaszadeh

2006-04-12T23:59:59.000Z

329

k - Version of Finite Element Method for Polymer flows using Giesekus Constitutive Model  

E-Print Network [OSTI]

and hence high Deborah number flows are invariably associated with higher flow rates and thus higher velocities. In many standard model problems such as couette flow, lid driven cavity, expansion, contraction etc, severe deborah number (De) limitations...

Deshpande, Kedar M.

2008-01-31T23:59:59.000Z

330

Adaptive Finite Element Method for Solving the Exact Kohn-Sham Equation of  

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 May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre the EffectsAcknowledgmentdynamics in

331

Modeling of three-dimensional viscoelastic flows with free surfaces using a finite element method  

E-Print Network [OSTI]

A framework and code have been developed to simulate fiber and film processes; the code can handle three-dimensional, isothermal, incompressible, creeping flow of a Giesekus fluid with free surfaces at infinite capillary ...

Adrian, David Joseph

2010-01-01T23:59:59.000Z

332

VARIATIONAL MULTISCALE FINITE ELEMENT METHOD FOR FLOWS IN HIGHLY POROUS MEDIA  

E-Print Network [OSTI]

to 99.7 % (see Figure 1.1(a)) and industrial foams with porosity up to 95% (see Figure 1.1(b)). In order in heterogeneous media is a difficult task which up to now is not fully mastered. (a) Glass wool

Lazarov, Raytcho

333

Bluff Body Flow Simulation Using a Vortex Element Method  

SciTech Connect (OSTI)

Heavy ground vehicles, especially those involved in long-haul freight transportation, consume a significant part of our nation's energy supply. it is therefore of utmost importance to improve their efficiency, both to reduce emissions and to decrease reliance on imported oil. At highway speeds, more than half of the power consumed by a typical semi truck goes into overcoming aerodynamic drag, a fraction which increases with speed and crosswind. Thanks to better tools and increased awareness, recent years have seen substantial aerodynamic improvements by the truck industry, such as tractor/trailer height matching, radiator area reduction, and swept fairings. However, there remains substantial room for improvement as understanding of turbulent fluid dynamics grows. The group's research effort focused on vortex particle methods, a novel approach for computational fluid dynamics (CFD). Where common CFD methods solve or model the Navier-Stokes equations on a grid which stretches from the truck surface outward, vortex particle methods solve the vorticity equation on a Lagrangian basis of smooth particles and do not require a grid. They worked to advance the state of the art in vortex particle methods, improving their ability to handle the complicated, high Reynolds number flow around heavy vehicles. Specific challenges that they have addressed include finding strategies to accurate capture vorticity generation and resultant forces at the truck wall, handling the aerodynamics of spinning bodies such as tires, application of the method to the GTS model, computation time reduction through improved integration methods, a closest point transform for particle method in complex geometrics, and work on large eddy simulation (LES) turbulence modeling.

Anthony Leonard; Phillippe Chatelain; Michael Rebel

2004-09-30T23:59:59.000Z

334

Method for the removal of elemental mercury from a gas stream  

DOE Patents [OSTI]

A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents. 7 figs.

Mendelsohn, M.H.; Huang, H.S.

1999-05-04T23:59:59.000Z

335

Method for the removal of elemental mercury from a gas stream  

DOE Patents [OSTI]

A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents.

Mendelsohn, Marshall H. (Downers Grove, IL); Huang, Hann-Sheng (Darien, IL)

1999-01-01T23:59:59.000Z

336

Adapting a Beam-Based Rotordynamics Model to Accept a General Three-Dimensional Finite-Element Casing Model  

E-Print Network [OSTI]

-dimensional axisymmetric beam-element code. ANSYS is used as a code to build three-dimensional non-axisymmetric solid-element casing models. The work done in this thesis opens the scope to incorporate complex non-axisymmetric casing models with XLTRC2....

James, Stephen M.

2011-08-08T23:59:59.000Z

337

Method for Detecting an Element - Energy Innovation Portal  

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: VegetationEquipment Surfaces andMapping theEnergy StorageAdvancedMetamaterialsInnovationEnergyMethod for

338

Finite-Temperature Non-equilibrium Quasicontinuum Method based on Langevin Dynamics  

SciTech Connect (OSTI)

The concurrent bridging of molecular dynamics and continuum thermodynamics presents a number of challenges, mostly associated with energy transmission and changes in the constitutive description of a material across domain boundaries. In this paper, we propose a framework for simulating coarse dynamic systems in the canonical ensemble using the Quasicontinuum method (QC). The equations of motion are expressed in reduced QC coordinates and are strictly derived from dissipative Lagrangian mechanics. The derivation naturally leads to a classical Langevin implementation where the timescale is governed by vibrations emanating from the finest length scale occurring in the computational cell. The equations of motion are integrated explicitly via Newmark's ({beta} = 0; {gamma} = 1/2) method, leading to a robust numerical behavior and energy conservation. In its current form, the method only allows for wave propagations supported by the less compliant of the two meshes across a heterogeneous boundary, which requires the use of overdamped dynamics to avoid spurious heating due to reflected vibrations. We have applied the method to two independent crystallographic systems characterized by different interatomic potentials (Al and Ta) and have measured thermal expansion in order to quantify the vibrational entropy loss due to homogenization. We rationalize the results in terms of system size, mesh coarseness, and nodal cluster diameter within the framework of the quasiharmonic approximation. For Al, we find that the entropy loss introduced by mesh coarsening varies linearly with the element size, and that volumetric effects are not critical in driving the anharmonic behavior of the simulated systems. In Ta, the anomalies of the interatomic potential employed result in negative and zero thermal expansion at low and high temperatures, respectively.

Marian, J; Venturini, G; Hansen, B; Knap, J; Ortiz, M; Campbell, G

2009-05-08T23:59:59.000Z

339

hp-Adaptive Multi-Physics Finite-Element Simulation of Wireline Borehole Sonic Waveforms Pawel J. Matuszyk and Carlos Torres-Verdin, University of Texas at Austin  

E-Print Network [OSTI]

-element method (FEM) to simulate wireline (WL) borehole acoustic waveforms. It works in the frequency domain of the components can be consid- ered as an acoustic fluid (A) or a linear elastic/viscoelastic solid (E). Wave of the pressure in a fluid, u(x,n) is a Fourier transform of the displacement in a solid, ¯p and ¯u

Torres-Verdín, Carlos

340

Continuum Models of Carbon Nanotube-Based Composites Using the Boundary Element Method  

E-Print Network [OSTI]

Continuum Models of Carbon Nanotube-Based Composites Using the Boundary Element Method Y.J. Liu)-based composites. Carbon nanotubes, formed conceptually by rolling thin graphite sheets, have been found to be extremely stiff, strong and resilient, and therefore may be ideal for reinforcing composite materials

Liu, Yijun

Note: This page contains sample records for the topic "finite element method" 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

PIERS ONLINE, VOL. 4, NO. 5, 2008 551 A Parallel, Fourier Finite-Element Formulation with an Iterative  

E-Print Network [OSTI]

of Science and Technology in Krakow, Poland Abstract-- We describe a new method to simulate resistivity-adaptive grid-refinement strategy. We apply the new method to simulate measurements acquired with a logging-while-drilling described in [12] with a new iterative solver specially designed for the FFE formulation. In addition, we

Torres-Verdín, Carlos

342

Serpentine: Finite Difference Methods for Wave Propagation in Second Order Formulation  

SciTech Connect (OSTI)

Wave propagation phenomena are important in many DOE applications such as nuclear explosion monitoring, geophysical exploration, estimating ground motion hazards and damage due to earthquakes, non-destructive testing, underground facilities detection, and acoustic noise propagation. There are also future applications that would benefit from simulating wave propagation, such as geothermal energy applications and monitoring sites for carbon storage via seismic reflection techniques. In acoustics and seismology, it is of great interest to increase the frequency bandwidth in simulations. In seismic exploration, greater frequency resolution enables shorter wave lengths to be included in the simulations, allowing for better resolution in the seismic imaging. In nuclear explosion monitoring, higher frequency seismic waves are essential for accurate discrimination between explosions and earthquakes. When simulating earthquake induced motion of large structures, such as nuclear power plants or dams, increased frequency resolution is essential for realistic damage predictions. Another example is simulations of micro-seismic activity near geothermal energy plants. Here, hydro-fracturing induces many small earthquakes and the time scale of each event is proportional to the square root of the moment magnitude. As a result, the motion is dominated by higher frequencies for smaller seismic events. The above wave propagation problems are all governed by systems of hyperbolic partial differential equations in second order differential form, i.e., they contain second order partial derivatives of the dependent variables. Our general research theme in this project has been to develop numerical methods that directly discretize the wave equations in second order differential form. The obvious advantage of working with hyperbolic systems in second order differential form, as opposed to rewriting them as first order hyperbolic systems, is that the number of differential equations in the second order system is significantly smaller. Another issue with re-writing a second order system into first order form is that compatibility conditions often must be imposed on the first order form. These (Saint-Venant) conditions ensure that the solution of the first order system also satisfies the original second order system. However, such conditions can be difficult to enforce on the discretized equations, without introducing additional modeling errors. This project has previously developed robust and memory efficient algorithms for wave propagation including effects of curved boundaries, heterogeneous isotropic, and viscoelastic materials. Partially supported by internal funding from Lawrence Livermore National Laboratory, many of these methods have been implemented in the open source software WPP, which is geared towards 3-D seismic wave propagation applications. This code has shown excellent scaling on up to 32,768 processors and has enabled seismic wave calculations with up to 26 Billion grid points. TheWPP calculations have resulted in several publications in the field of computational seismology, e.g.. All of our current methods are second order accurate in both space and time. The benefits of higher order accurate schemes for wave propagation have been known for a long time, but have mostly been developed for first order hyperbolic systems. For second order hyperbolic systems, it has not been known how to make finite difference schemes stable with free surface boundary conditions, heterogeneous material properties, and curvilinear coordinates. The importance of higher order accurate methods is not necessarily to make the numerical solution more accurate, but to reduce the computational cost for obtaining a solution within an acceptable error tolerance. This is because the accuracy in the solution can always be improved by reducing the grid size h. However, in practice, the available computational resources might not be large enough to solve the problem with a low order method.

Petersson, N A; Sjogreen, B

2012-03-26T23:59:59.000Z

343

Geomechanical Simulations of Caprock Integrity Using the Livermore Distinict Element Method  

SciTech Connect (OSTI)

Large-scale carbon capture and sequestration (CCS) projects involving annual injections of millions of tons of CO2 are a key infrastructural element needed to substantially reduce greenhouse gas emissions. The large rate and volume of injection will induce pressure and stress gradients within the formation that could activate existing fractures and faults, or drive new fractures through the caprock. We will present results of an ongoing investigation to identify conditions that will activate existing fractures/faults or make new fractures within the caprock using the Livermore Distinct Element Code (LDEC). LDEC is a multiphysics code, developed at LLNL, capable of simulating dynamic fracture of rock masses under a range of conditions. As part of a recent project, LDEC has been extended to consider fault activation and dynamic fracture of rock masses due to pressurization of the pore-space. We will present several demonstrations of LDEC functionality and an application of LDEC to a CO2 injection scenario. We present results from our investigations of Teapot Dome using LDEC to study the potential for fault activation during injection. Using this approach, we built finite element models of the rock masses surrounding bounding faults and explicitly simulated the compression and shear on the fault interface. A CO2 injection source was introduced and the area of fault activation was predicted as a function of injection rate. This work presents an approach where the interactions of all locations on the fault are considered in response to specific injection scenarios. For example, with LDEC, as regions of the fault fail, the shear load is taken up elsewhere on the fault. The results of this study are consistent with previous studies of Teapot Dome and indicate significantly elevated pore pressures are required to activate the bounding faults, given the assumed in situ stress state on the faults.

Morris, J; Johnson, S; Friedmann, S J

2008-04-17T23:59:59.000Z

344

Geomechanical Simulations of CO2 Storage Integrity using the Livermore Distinct Element Method  

SciTech Connect (OSTI)

Large-scale carbon capture and sequestration (CCS) projects involving annual injections of millions of tons of CO{sub 2} are a key infrastructural element needed to substantially reduce greenhouse gas emissions. The large rate and volume of injection will induce pressure and stress gradients within the formation that could activate existing fractures and faults, or drive new fractures through the caprock. We will present results of an ongoing investigation to identify conditions that will activate existing fractures/faults or make new fractures within the caprock using the Livermore Distinct Element Code (LDEC). LDEC is a multiphysics code, developed at LLNL, capable of simulating dynamic fracture of rock masses under a range of conditions. As part of a recent project, LDEC has been extended to consider fault activation and dynamic fracture of rock masses due to pressurization of the pore-space. We will present several demonstrations of LDEC functionality and applications of LDEC to CO{sub 2} injection scenarios including injection into an extensively fractured rockmass. These examples highlight the advantages of explicitly including the geomechanical response of each interface within the rockmass. We present results from our investigations of Teapot Dome using LDEC to study the potential for fault activation during injection. Using this approach, we built finite element models of the rock masses surrounding bounding faults and explicitly simulated the compression and shear on the fault interface. A CO{sub 2} injection source was introduced and the area of fault activation was predicted as a function of injection rate. This work presents an approach where the interactions of all locations on the fault are considered in response to specific injection scenarios. For example, with LDEC, as regions of the fault fail, the shear load is taken up elsewhere on the fault. The results of this study are consistent with previous studies of Teapot Dome and indicate significantly elevated pore pressures are required to activate the bounding faults, given the assumed in situ stress state on the faults.

Morris, J P; Johnson, S M; Friedmann, S J

2008-07-11T23:59:59.000Z

345

A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry  

SciTech Connect (OSTI)

A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible NavierStokes equations using an explicit time advancement scheme and high-order finite differences. This NavierStokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as well as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium.

Marxen, Olaf, E-mail: olaf.marxen@vki.ac.be [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States) [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States); Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium); Magin, Thierry E. [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium)] [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium); Shaqfeh, Eric S.G.; Iaccarino, Gianluca [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)] [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)

2013-12-15T23:59:59.000Z

346

FINITE-ELEMENT ANALYSIS OF ROCK FALL ON UNCANISTERED FUEL WASTE PACKAGE DESIGNS (SCPB: N/A)  

SciTech Connect (OSTI)

The objective of this analysis is to explore the Uncanistered Fuel (UCF) Tube Design waste package (WP) resistance to rock falls. This analysis will also be used to determine the size of rock that can strike the WP without causing failure in the containment barriers from a height based on the starter tunnel dimensions. The purpose of this analysis is to document the models and methods used in the calculations.

Z. Ceylan

1996-10-18T23:59:59.000Z

347

Parallel, Multigrid Finite Element Simulator for Fractured/Faulted and Other Complex Reservoirs based on Common Component Architecture (CCA)  

SciTech Connect (OSTI)

Black-oil, compositional and thermal simulators have been developed to address different physical processes in reservoir simulation. A number of different types of discretization methods have also been proposed to address issues related to representing the complex reservoir geometry. These methods are more significant for fractured reservoirs where the geometry can be particularly challenging. In this project, a general modular framework for reservoir simulation was developed, wherein the physical models were efficiently decoupled from the discretization methods. This made it possible to couple any discretization method with different physical models. Oil characterization methods are becoming increasingly sophisticated, and it is possible to construct geologically constrained models of faulted/fractured reservoirs. Discrete Fracture Network (DFN) simulation provides the option of performing multiphase calculations on spatially explicit, geologically feasible fracture sets. Multiphase DFN simulations of and sensitivity studies on a wide variety of fracture networks created using fracture creation/simulation programs was undertaken in the first part of this project. This involved creating interfaces to seamlessly convert the fracture characterization information into simulator input, grid the complex geometry, perform the simulations, and analyze and visualize results. Benchmarking and comparison with conventional simulators was also a component of this work. After demonstration of the fact that multiphase simulations can be carried out on complex fracture networks, quantitative effects of the heterogeneity of fracture properties were evaluated. Reservoirs are populated with fractures of several different scales and properties. A multiscale fracture modeling study was undertaken and the effects of heterogeneity and storage on water displacement dynamics in fractured basements were investigated. In gravity-dominated systems, more oil could be recovered at a given pore volume of injection at lower rates. However, if oil production can be continued at high water cuts, the discounted cumulative production usually favors higher production rates. The workflow developed during the project was also used to perform multiphase simulations in heterogeneous, fracture-matrix systems. Compositional and thermal-compositional simulators were developed for fractured reservoirs using the generalized framework. The thermal-compositional simulator was based on a novel 'equation-alignment' approach that helped choose the correct variables to solve depending on the number of phases present and the prescribed component partitioning. The simulators were used in steamflooding and in insitu combustion applications. The framework was constructed to be inherently parallel. The partitioning routines employed in the framework allowed generalized partitioning on highly complex fractured reservoirs and in instances when wells (incorporated in these models as line sources) were divided between two or more processors.

Milind Deo; Chung-Kan Huang; Huabing Wang

2008-08-31T23:59:59.000Z

348

Inverse transonic wing design using finite-volume methods in curvilinear coordinates  

E-Print Network [OSTI]

&U)i j k = (Ui~h j~b k+ Ui+Q j Q k + Ui Q j+Q k+ Ui h j h k)/4 etc. When extended to the other flux components and to averaging over cube surfaces in three dimensions, the numerical potential equation is of the form: @&f6'(PhU) + @[f6?(PhV) + Pf 6f...(PhW) = 0 Figure 2. Finite-Volume Cell Location To find the flux quantities phU, phV, and phW at the finite volume cell vertices (i. e. points a, b, c, and d for the two dimensional case), it is necessary to evaluate Equations (2) through (4...

Gally, Thomas Anthony

2012-06-07T23:59:59.000Z

349

An adaptively refined phase-space element method for cosmological simulations and collisionless dynamics  

E-Print Network [OSTI]

Dark matter numerical simulations and the N-body method are essential for understanding how structure forms and evolves in the Universe. However, the discrete nature of N-body simulations can affect its accuracy when modelling collisionless systems. We introduce a new approach to simulate the gravitational evolution of cold collisionless fluids by solving the Vlasov-Poisson equations in terms of adaptively refineable "Lagrangian phase space elements". These geometrical elements are piecewise smooth maps between three-dimensional Lagrangian space and six-dimensional Eulerian phase space and approximate the continuum structure of the distribution function. They allow for dynamical adaptive splitting to follow the evolution even in regions of very strong mixing. We discuss various test problems which demonstrate the correctness and performance of our method. We show that it has several advantages compared to standard N-body algorithms by i) explicitly tracking the fine-grained distribution function, ii) naturall...

Hahn, Oliver

2015-01-01T23:59:59.000Z

350

Stein's method, heat kernel, and traces of powers of elements of compact Lie groups  

E-Print Network [OSTI]

Combining Stein's method with heat kernel techniques, we show that the trace of the jth power of an element of U(n,C), USp(n,C) or SO(n,R) has a normal limit with error term of order j/n. In contrast to previous works, here j may be growing with n. The technique should prove useful in the study of the value distribution of approximate eigenfunctions of Laplacians.

Jason Fulman

2010-05-07T23:59:59.000Z

351

Coupled numerical approach combining finite volume and lattice Boltzmann methods for multi-scale multi-physicochemical processes  

SciTech Connect (OSTI)

A coupled (hybrid) simulation strategy spatially combining the finite volume method (FVM) and the lattice Boltzmann method (LBM), called CFVLBM, is developed to simulate coupled multi-scale multi-physicochemical processes. In the CFVLBM, computational domain of multi-scale problems is divided into two sub-domains, i.e., an open, free fluid region and a region filled with porous materials. The FVM and LBM are used for these two regions, respectively, with information exchanged at the interface between the two sub-domains. A general reconstruction operator (RO) is proposed to derive the distribution functions in the LBM from the corresponding macro scalar, the governing equation of which obeys the convectiondiffusion equation. The CFVLBM and the RO are validated in several typical physicochemical problems and then are applied to simulate complex multi-scale coupled fluid flow, heat transfer, mass transport, and chemical reaction in a wall-coated micro reactor. The maximum ratio of the grid size between the FVM and LBM regions is explored and discussed. -- Highlights: A coupled simulation strategy for simulating multi-scale phenomena is developed. Finite volume method and lattice Boltzmann method are coupled. A reconstruction operator is derived to transfer information at the sub-domains interface. Coupled multi-scale multiple physicochemical processes in micro reactor are simulated. Techniques to save computational resources and improve the efficiency are discussed.

Chen, Li; He, Ya-Ling [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)] [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Kang, Qinjun [Computational Earth Science Group (EES-16), Los Alamos National Laboratory, Los Alamos, NM (United States)] [Computational Earth Science Group (EES-16), Los Alamos National Laboratory, Los Alamos, NM (United States); Tao, Wen-Quan, E-mail: wqtao@mail.xjtu.edu.cn [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)] [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2013-12-15T23:59:59.000Z

352

Optical sensing elements for nitrogen dioxide (NO.sub.2) gas detection, a sol-gel method for making the sensing elements and fiber optic sensors incorporating nitrogen dioxide gas optical sensing elements  

DOE Patents [OSTI]

A sensing element, a method of making a sensing element, and a fiber optic sensor incorporating the sensing element are described. The sensor can be used for the quantitative detection of NO.sub.2 in a mixture of gases. The sensing element can be made by incorporating a diazotizing reagent which reacts with nitrous ions to produce a diazo compound and a coupling reagent which couples with the diazo compound to produce an azo dye into a sol and allowing the sol to form an optically transparent gel. The sensing element changes color in the presence of NO.sub.2 gas. The temporal response of the absorption spectrum at various NO.sub.2 concentrations has also been recorded and analyzed. Sensors having different design configurations are described. The sensing element can detect NO.sub.2 gas at levels of parts per billion.

Mechery, Shelly John (Mississippi State, MS); Singh, Jagdish P. (Starkville, MS)

2007-07-03T23:59:59.000Z

353

Spectral distribution method for neutrinoless double-beta decay nuclear transition matrix elements: Binary correlation results  

E-Print Network [OSTI]

Neutrinoless double-beta decay nuclear transition matrix elements are generated by an effective two-body transition operator and it consists of Gamow-Teller like and Fermi like (also tensor) operators. Spectral distribution method for the corresponding transition strengths (squares of the transition matrix elements) involves convolution of the transition strength density generated by the non-interacting particle part of the Hamiltonian with a spreading function generated by the two-body part of the Hamiltonian. Extending the binary correlation theory for spinless embedded $k$-body ensembles to ensembles with proton-neutron degrees of freedom, we establish that the spreading function is a bivariate Gaussian for transition operators $\\co(k_\\co)$ that change $k_\\co$ number of neutrons to $k_\\co$ number of protons. Towards this end, we have derived the formulas for the fourth-order cumulants of the spreading function and calculated their values for some heavy nuclei; they are found to vary from $\\sim -0.4$ to -0.1. Also for nuclei from $^{76}$Ge to $^{238}$U, the bivariate correlation coefficient is found to vary from $\\sim 0.6 - 0.8$ and these values can be used as a starting point for calculating nuclear transition matrix elements using the spectral distribution method.

Manan Vyas; V. K. B. Kota

2011-06-02T23:59:59.000Z

354

Efficient numerical solver for first-principles transport calculation based on real-space finite-difference method  

E-Print Network [OSTI]

We propose an efficient procedure to obtain Green's functions by combining the shifted conjugate orthogonal conjugate gradient (shifted COCG) method with the nonequilibrium Green's function (NEGF) method based on a real-space finite-difference (RSFD) approach. The bottleneck of the computation in the NEGF scheme is matrix inversion of the Hamiltonian including the self-energy terms of electrodes to obtain perturbed Green's function in the transition region. This procedure first computes unperturbed Green's functions and calculates perturbed Green's functions from the unperturbed ones using a mathematically strict relation. Since the matrices to be inverted to obtain the unperturbed Green's functions are sparse, complex-symmetric and shifted for a given set of sampling energy points, we can use the shifted COCG method, in which once the Green's function for a reference energy point has been calculated, the Green's functions for the other energy points can be obtained with a moderate computational cost. We calc...

Iwase, Shigeru; Ono, Tomoya

2015-01-01T23:59:59.000Z

355

Mixed and Nonconforming Finite Elements  

E-Print Network [OSTI]

Apr 28, 2008 ... tor is then free of over-refinements and satisfies the efficiency and ...... put a c here is to make the error estimator is comparable with the energy.

2009-10-28T23:59:59.000Z

356

Transient analysis of printed lines using finite-difference time-domain method  

SciTech Connect (OSTI)

Comprehensive studies of ultra-wideband pulses and electromagnetic coupling on printed coupled lines have been performed using full-wave 3D finite-difference time-domain analysis. Effects of unequal phase velocities of coupled modes, coupling between line traces, and the frequency dispersion on the waveform fidelity and crosstalk have been investigated in detail. To discriminate the contributions of different mechanisms into pulse evolution, single and coupled microstrip lines without (?r?=?1) and with (?r?>?1) dielectric substrates have been examined. To consistently compare the performance of the coupled lines with substrates of different permittivities and transients of different characteristic times, a generic metric similar to the electrical wavelength has been introduced. The features of pulse propagation on coupled lines with layered and pedestal substrates and on the irregular traces have been explored. Physical interpretations of the simulation results are discussed in the paper.

Ahmed, Shahid [JLAB

2013-01-01T23:59:59.000Z

357

A bridge-functional-based classical mapping method for predicting the correlation functions of uniform electron gases at finite temperature  

SciTech Connect (OSTI)

Efficient and accurate prediction of the correlation functions of uniform electron gases is of great importance for both practical and theoretical applications. This paper presents a bridge-functional-based classical mapping method for calculating the correlation functions of uniform spin-unpolarized electron gases at finite temperature. The bridge functional is formulated by following Rosenfeld's universality ansatz in combination with the modified fundamental measure theory. The theoretical predictions are in good agreement with recent quantum Monte Carlo results but with negligible computational cost, and the accuracy is better than a previous attempt based on the hypernetted-chain approximation. We find that the classical mapping method is most accurate if the effective mass of electrons increases as the density falls.

Liu, Yu; Wu, Jianzhong, E-mail: jwu@engr.ucr.edu [Department of Chemical and Environmental Engineering and Department of Mathematics, University of California, Riverside, California 92521 (United States)] [Department of Chemical and Environmental Engineering and Department of Mathematics, University of California, Riverside, California 92521 (United States)

2014-02-28T23:59:59.000Z

358

95TILING FOR STATIONARY METHODS SPARSE TILING FOR STATIONARY  

E-Print Network [OSTI]

­Seidel operating on sparse matrices. In scientific applications such as finite element analysis, these itera- tive of stationary iterative methods operating on sparse matrices. In scientific appli- cations, such as finite element analysis (FEA), these iter- ative methods dominate the execution time. FEA is a numerical

Strout, Michelle Mills

359

An Efficient, Semi-implicit Pressure-based Scheme Employing a High-resolution Finitie Element Method for Simulating Transient and Steady, Inviscid and Viscous, Compressible Flows on Unstructured Grids  

SciTech Connect (OSTI)

A new semi-implicit pressure-based Computational Fluid Dynamics (CFD) scheme for simulating a wide range of transient and steady, inviscid and viscous compressible flow on unstructured finite elements is presented here. This new CFD scheme, termed the PCICEFEM (Pressure-Corrected ICE-Finite Element Method) scheme, is composed of three computational phases, an explicit predictor, an elliptic pressure Poisson solution, and a semiimplicit pressure-correction of the flow variables. The PCICE-FEM scheme is capable of second-order temporal accuracy by incorporating a combination of a time-weighted form of the two-step Taylor-Galerkin Finite Element Method scheme as an explicit predictor for the balance of momentum equations and the finite element form of a time-weighted trapezoid rule method for the semi-implicit form of the governing hydrodynamic equations. Second-order spatial accuracy is accomplished by linear unstructured finite element discretization. The PCICE-FEM scheme employs Flux-Corrected Transport as a high-resolution filter for shock capturing. The scheme is capable of simulating flows from the nearly incompressible to the high supersonic flow regimes. The PCICE-FEM scheme represents an advancement in mass-momentum coupled, pressurebased schemes. The governing hydrodynamic equations for this scheme are the conservative form of the balance of momentum equations (Navier-Stokes), mass conservation equation, and total energy equation. An operator splitting process is performed along explicit and implicit operators of the semi-implicit governing equations to render the PCICE-FEM scheme in the class of predictor-corrector schemes. The complete set of semi-implicit governing equations in the PCICE-FEM scheme are cast in this form, an explicit predictor phase and a semi-implicit pressure-correction phase with the elliptic pressure Poisson solution coupling the predictor-corrector phases. The result of this predictor-corrector formulation is that the pressure Poisson equation in the PCICE-FEM scheme is provided with sufficient internal energy information to avoid iteration. The ability of the PCICE-FEM scheme to accurately and efficiently simulate a wide variety of inviscid and viscous compressible flows is demonstrated here.

Richard C. Martineau; Ray A. Berry

2003-04-01T23:59:59.000Z

360

A high-order finite-volume method for hyperbolic conservation laws on locally-refined grids  

SciTech Connect (OSTI)

We present a fourth-order accurate finite-volume method for solving time-dependent hyperbolic systems of conservation laws on Cartesian grids with multiple levels of refinement. The underlying method is a generalization of that in [5] to nonlinear systems, and is based on using fourth-order accurate quadratures for computing fluxes on faces, combined with fourth-order accurate Runge?Kutta discretization in time. To interpolate boundary conditions at refinement boundaries, we interpolate in time in a manner consistent with the individual stages of the Runge-Kutta method, and interpolate in space by solving a least-squares problem over a neighborhood of each target cell for the coefficients of a cubic polynomial. The method also uses a variation on the extremum-preserving limiter in [8], as well as slope flattening and a fourth-order accurate artificial viscosity for strong shocks. We show that the resulting method is fourth-order accurate for smooth solutions, and is robust in the presence of complex combinations of shocks and smooth flows.

McCorquodale, Peter; Colella, Phillip

2011-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

A GPU Parallelized Spectral Method For Elliptic Equations.  

E-Print Network [OSTI]

ence methods [6], finite element methods [24, 14, 13], Fourier spectral methods .... stored on the GPU once and for all, in order to minimize data transfer between the ..... The spectrum of the Chebyshev collocation operator for the heat equation.

2013-04-29T23:59:59.000Z

362

Computational upscaled modeling of heterogeneous porous media flow utilizing finite volume method  

E-Print Network [OSTI]

. Finally we will present several applications of the multiscale method in the ?ow in porous media. Problems that we will consider are multiphase immiscible ?ow, multicomponent miscible ?ow, and soil in?ltration in saturated/unsaturated...

Ginting, Victor Eralingga

2005-08-29T23:59:59.000Z

363

An Upwind Finite-Difference Method for Total VariationBased ...  

E-Print Network [OSTI]

AMS subject classifications. 65D18 ...... We begin by discussing the efficiency improvements we observed by our multiscale method. ..... [14] A. Chambolle, Total variation minimization and a class of binary mrf models, in Proceedings of Energy.

2011-03-17T23:59:59.000Z

364

Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method  

SciTech Connect (OSTI)

The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2008-12-01T23:59:59.000Z

365

Calculation of large ion densities under HVdc transmission lines by the finite difference method  

SciTech Connect (OSTI)

A calculation method for large ion densities (charged aerosols) under HVdc transmission lines was developed considering both the charging mechanism of aerosols by small ions and the drifting process by wind. Large ion densities calculated by this method agreed well with the ones measured under the Shiobara HVdc test line on the lateral profiles at ground level up to about 70m downwind from the line. Measured values decreased more quickly than calculated ones farther downwind from the line. Considering the effect of point discharge from ground cover (earth corona) improved the agreement in the farther downwind region.

Suda, Tomotaka; Sunaga, Yoshitaka [Central Research Institute of Electrical Power Industry, Komae, Tokyo (Japan)] [Central Research Institute of Electrical Power Industry, Komae, Tokyo (Japan)

1995-10-01T23:59:59.000Z

366

A graphical preprocessing interface for non-conforming spectral element solvers  

E-Print Network [OSTI]

Page 1 Left: Discretization of a square using 50?50 1 st order elements by FEM. Right: Discretizations of a square using 50 th -order single domain with SM... representative numerical technique of this kind is the Finite Element Method (FEM) [2]. It uses small finite number of elements with low order approximation functions (Fig. 1 left). When engineering models have complex geometry, FEM discretizes the geometry (e...

Kim, Bo Hung

2009-06-02T23:59:59.000Z

367

Methods for manufacturing porous nuclear fuel elements for high-temperature gas-cooled nuclear reactors  

DOE Patents [OSTI]

Methods for manufacturing porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's). Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, a thin coating of nuclear fuel may be deposited inside of a highly porous skeletal structure made, for example, of reticulated vitreous carbon foam.

Youchison, Dennis L. (Albuquerque, NM); Williams, Brian E. (Pocoima, CA); Benander, Robert E. (Pacoima, CA)

2010-02-23T23:59:59.000Z

368

Investigations of ?-helix??-sheet transition pathways in a miniprotein using the finite-temperature string method  

SciTech Connect (OSTI)

A parallel implementation of the finite-temperature string method is described, which takes into account the invariance of coordinates with respect to rigid-body motions. The method is applied to the complex ?-helix??-sheet transition in a ?-hairpin miniprotein in implicit solvent, which exhibits much of the complexity of conformational changes in proteins. Two transition paths are considered, one derived from a linear interpolant between the endpoint structures and the other derived from a targeted dynamics simulation. Two methods for computing the conformational free energy (FE) along the string are compared, a restrained method, and a tessellation method introduced by E. Vanden-Eijnden and M. Venturoli [J. Chem. Phys. 130, 194103 (2009)]. It is found that obtaining meaningful free energy profiles using the present atom-based coordinates requires restricting sampling to a vicinity of the converged path, where the hyperplanar approximation to the isocommittor surface is sufficiently accurate. This sampling restriction can be easily achieved using restraints or constraints. The endpoint FE differences computed from the FE profiles are validated by comparison with previous calculations using a path-independent confinement method. The FE profiles are decomposed into the enthalpic and entropic contributions, and it is shown that the entropy difference contribution can be as large as 10 kcal/mol for intermediate regions along the path, compared to 1520 kcal/mol for the enthalpy contribution. This result demonstrates that enthalpic barriers for transitions are offset by entropic contributions arising from the existence of different paths across a barrier. The possibility of using systematically coarse-grained representations of amino acids, in the spirit of multiple interaction site residue models, is proposed as a means to avoid ad hoc sampling restrictions to narrow transition tubes.

Ovchinnikov, Victor, E-mail: ovchinnv@georgetown.edu [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)] [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Karplus, Martin, E-mail: marci@tammy.harvard.edu [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Laboratoire de Chimie Biophysique, ISIS, Universit de Strasbourg, 67000 Strasbourg (France)

2014-05-07T23:59:59.000Z

369

Performance study of plane wave finite element methods with a Pade-type artificial boundary condition in  

E-Print Network [OSTI]

condition in acoustic scattering R. Kechroud , A. Soulaimani , X. Antoine Abstract The aim of this paper are met. Indeed, it is well-known that pollution effects [10, 11, 12] arise in standard FEM limiting

Paris-Sud XI, Université de

370

Discontinuous Galerkin Finite Element Method for the Nonlinear Hyperbolic Problems with Entropy-Based Artificial Viscosity Stabilization  

E-Print Network [OSTI]

. Theo- retically, solutions may be obtained to an arbitrarily high order of accuracy. While the DG FEM was proposed in the early 1970?s by Reed and Hill for the neutron transport equation [10], it was not used for CFD simulations until the early 1990... period of this work. vii NOMENCLATURE BC?s boundary conditions BDF backward differentiation formula CD centered difference CFD computational fluid dynamics CFL Courant-Friedrichs-Lewy CG continuous Galerkin CN Crank-Nicholson DG discontinuous...

Zingan, Valentin Nikolaevich

2012-07-16T23:59:59.000Z

371

A high-order, adaptive, discontinuous Galerkin finite element method for the Reynolds-Averaged Navier-Stokes equations  

E-Print Network [OSTI]

This thesis presents high-order, discontinuous Galerkin (DG) discretizations of the Reynolds-Averaged Navier-Stokes (RANS) equations and an output-based error estimation and mesh adaptation algorithm for these discretizations. ...

Oliver, Todd A., 1980-

2008-01-01T23:59:59.000Z

372

Shock capturing with PDE-based artificial viscosity for an adaptive, higher-order discontinuous Galerkin finite element method  

E-Print Network [OSTI]

The accurate simulation of supersonic and hypersonic flows is well suited to higher-order (p > 1), adaptive computational fluid dynamics (CFD). Since these cases involve flow velocities greater than the speed of sound, an ...

Barter, Garrett E. (Garrett Ehud), 1979-

2008-01-01T23:59:59.000Z

373

Shock Capturing with PDE-Based Artificial Viscosity for an Adaptive, Higher-Order Discontinuous Galerkin Finite Element Method  

E-Print Network [OSTI]

The accurate simulation of supersonic and hypersonic flows is well suited to higher-order (p > 1), adaptive computational fluid dynamics (CFD). Since these cases involve flow velocities greater than the speed of sound, an ...

Barter, Garrett Ehud

374

APPROXIMATION THEORY FOR THE P-VERSION OF THE FINITE ELEMENT METHOD IN THREE DIMENSIONS IN THE  

E-Print Network [OSTI]

Neal Schwendler, CA, USA), Poly FEM(IBM, MA USA), MECHANICA (Rasna Corp., CA, USA), PHLEX (Computational Mechanics

375

Supporting material for the paper 'Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation'  

E-Print Network [OSTI]

compilation of the form parameters.optimize = True # Define boundary of domain class Boundary(SubDomain): def inside(self, x, on_boundary): return on_boundary def solve(mesh, order, model): # Advective velocity V_b = VectorFunctionSpace(mesh, "CG", order+6) b... , V: Constant(V.mesh(), (4.0/5.0, 3.0/5.0)) tmp0 = "(cos((pi*(1+x[0])*(1+x[1])*(1+x[1])/8))*pi*(1+x[1])*(1+x[1])/8)" tmp1 = "(cos((pi*(1+x[0])*(1+x[1])*(1+x[1])/8))*2*pi*(1+x[0])*(1+x[1])/8)" source = "(4.0/5.0)*tmp0 + (3.0/5.0)*tmp1 + 1 + sin((pi*(1+x...

Wells, G N

2009-10-28T23:59:59.000Z

376

Proper orthogonal decomposition approach and error estimation of mixed finite element methods for the tropical Pacific Ocean  

E-Print Network [OSTI]

for the tropical Pacific Ocean reduced gravity model Zhendong Luo a , Jiang Zhu b , Ruiwen Wang b , I.M. Navon c Available online 8 May 2007 Abstract In this paper, the tropical Pacific Ocean reduced gravity model and the insufficient knowledge of air­sea exchange processes. The tropical Pacific Ocean reduced gravity model

Navon, Michael

377

Three-phase compositional modeling of CO2 injection by higher-order finite element methods with CPA equation  

E-Print Network [OSTI]

and gravitational fingering that can negatively affect hydrocarbon (HC) recovery, or aid carbon sequestration and other simulators. The examples consider gravitational fingering during CO2 sequestration in aquifers could have a significant impact on CO2 sequestration and IOR. Accurate simulation of compositional

Firoozabadi, Abbas

378

An iterative finite element time-domain method for simulating three-dimensional electromagnetic diffusion in earth  

E-Print Network [OSTI]

of an axially symmetric earth for vertical magnetic dipoleDevelopment Grants from Earth Sciences Division. Editor Dr.electromagnetic diffusion in earth Evan Schankee Um, 1 Jerry

Um, E.S.

2013-01-01T23:59:59.000Z

379

IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full Waveform Acoustic  

E-Print Network [OSTI]

, isotropic, composite system consisting of a fluid-filled well bore Qf through a fluid-saturated porous solid-filled borehole Qf through a fluid-saturated porous solid Qp. The problem arises naturally in acoustic well in the model. This paper is related to several previous works on the subject. The theory of propagation

Harrison, Mark

380

A concurrent precursor inflow method for Large Eddy Simulations and applications to finite length wind farms  

E-Print Network [OSTI]

In order to enable simulations of developing wind turbine array boundary layers with highly realistic inflow conditions a concurrent precursor method for Large Eddy Simulations is proposed. In this method we consider two domains simultaneously, i.e. in one domain a turbulent Atmospheric Boundary Layer (ABL) without wind turbines is simulated in order to generate the turbulent inflow conditions for a second domain in which the wind turbines are placed. The benefit of this approach is that a) it avoids the need for large databases in which the turbulent inflow conditions are stored and the correspondingly slow I/O operations and b) we are sure that the simulations are not negatively affected by statically swept fixed inflow fields or synthetic fields lacking the proper ABL coherent structures. Sample applications are presented, in which, in agreement with field data a strong decrease of the power output of downstream wind-turbines with respect to the first row of wind-turbines is observed for perfectly aligned ...

Stevens, Richard J A M; Meneveau, Charles

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Study on small-strain behaviours of methane hydrate sandy sediments using discrete element method  

SciTech Connect (OSTI)

Methane hydrate bearing soil has attracted increasing interest as a potential energy resource where methane gas can be extracted from dissociating hydrate-bearing sediments. Seismic testing techniques have been applied extensively and in various ways, to detect the presence of hydrates, due to the fact that hydrates increase the stiffness of hydrate-bearing sediments. With the recognition of the limitations of laboratory and field tests, wave propagation modelling using Discrete Element Method (DEM) was conducted in this study in order to provide some particle-scale insights on the hydrate-bearing sandy sediment models with pore-filling and cementation hydrate distributions. The relationship between shear wave velocity and hydrate saturation was established by both DEM simulations and analytical solutions. Obvious differences were observed in the dependence of wave velocity on hydrate saturation for these two cases. From the shear wave velocity measurement and particle-scale analysis, it was found that the small-strain mechanical properties of hydrate-bearing sandy sediments are governed by both the hydrate distribution patterns and hydrate saturation.

Yu Yanxin; Cheng Yipik [Department of Civil, Environmental and Geomatic Engineering, University College London (UCL), Gower Street, London, WC1E 6BT (United Kingdom); Xu Xiaomin; Soga, Kenichi [Geotechnical and Environmental Research Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ (United Kingdom)

2013-06-18T23:59:59.000Z

382

GOMA 6.0 : a full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport : user%3CU%2B2019%3Es guide.  

SciTech Connect (OSTI)

Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a user's guide and reference.

Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken Shuang; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew Morgan; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B. [3M Engineering Systems and Technology, St. Paul, MN] [3M Engineering Systems and Technology, St. Paul, MN

2013-07-01T23:59:59.000Z

383

Method And Apparatus For Coupling Optical Elements To Optoelectronic Devices For Manufacturing Optical Transceiver Modules  

DOE Patents [OSTI]

A process is provided for aligning and connecting at least one optical fiber to at least one optoelectronic device so as to couple light between at least one optical fiber and at least one optoelectronic device. One embodiment of this process comprises the following steps: (1) holding at least one optical element close to at least one optoelectronic device, at least one optical element having at least a first end; (2) aligning at least one optical element with at least one optoelectronic device; (3) depositing a first non-opaque material on a first end of at least one optoelectronic device; and (4) bringing the first end of at least one optical element proximate to the first end of at least one optoelectronic device in such a manner that the first non-opaque material contacts the first end of at least one optoelectronic device and the first end of at least one optical element. The optical element may be an optical fiber, and the optoelectronic device may be a vertical cavity surface emitting laser. The first non-opaque material may be a UV optical adhesive that provides an optical path and mechanical stability. In another embodiment of the alignment process, the first end of at least one optical element is brought proximate to the first end of at least one optoelectronic device in such a manner that an interstitial space exists between the first end of at least one optoelectronic device and the first end of at least one optical element.

Anderson, Gene R. (Albuquerque, NM); Armendariz, Marcelino G. (Albuquerque, NM); Bryan, Robert P. (Albuquerque, NM); Carson, Richard F. (Albuquerque, NM); Chu, Dahwey (Albuquerque, NM); Duckett, III, Edwin B. (Albuquerque, NM); Giunta, Rachel Knudsen (Albuquerque, NM); Mitchell, Robert T. (Albuquerque, NM); McCormick, Frederick B. (Albuquerque, NM); Peterson, David W. (Sandia Park, NM); Rising, Merideth A. (Santa Fe, NM); Reber, Cathleen A. (Corrales, NM); Reysen, Bill H. (Lafayette, CO)

2005-06-14T23:59:59.000Z

384

A few new (?) facts about infinite elements  

E-Print Network [OSTI]

Keywords: Helmholtz equation; Infinite element; hp finite elements; Echo Area. 1. .... g : ? ouinc on . ?2.1?. The Sommerfeld radiation condition represents a...

2006-04-24T23:59:59.000Z

385

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector  

DOE Patents [OSTI]

Apparatus and method for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO.sub.2 laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart.

Strauss, Charlie E. (Santa Fe, NM)

1997-01-01T23:59:59.000Z

386

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector  

DOE Patents [OSTI]

Apparatus and method are disclosed for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO{sub 2} laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart. 4 figs.

Strauss, C.E.

1997-11-18T23:59:59.000Z

387

Prediction of potential and current density distribution using the boundary element method  

E-Print Network [OSTI]

boundary. 12 7. Discontinuous 2D boundary elements in intrinsic coordinate system. . . . . 25 8. Discontinuous 3D linear (boundary) element (a) global coordinates (b) intrinsic coordinates. 30 9. A simple galvanic corrosion couple (potential field... in two dimensions). . . 35 10. Potential distribution along the surface of the electrodes (i. e. , at yW). . . . 38 11. A simple problem of a cube (potential field in three dimensions). . . , . . . 41 12. Corrosion cell (a) perspective (b) cross...

Pakalapati, Surya Narayana Raju

1992-01-01T23:59:59.000Z

388

Separation of transplutonium elements by the method of emulsion membrane extraction  

SciTech Connect (OSTI)

A study is made of the kinetics of extraction of transplutonium elements by liquid emulsions of the type water and oil, containing di-2-ethylhexylphosphoric acid as the carrier and span-80 as the emulsifier. Conditions of efficient extraction and separation of three-valence americium, curium, and californium from solutions of diethylenetriaminepentaacetic acid are identified.

Novikov, A.P.; Myasoedov, B.F.

1988-05-01T23:59:59.000Z

389

Monolithic amplifier with stable, high resistance feedback element and method for fabricating the same  

DOE Patents [OSTI]

A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit. 11 figs.

O`Connor, P.

1998-08-11T23:59:59.000Z

390

Monolithic amplifier with stable, high resistance feedback element and method for fabricating the same  

DOE Patents [OSTI]

A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit.

O'Connor, Paul (Bellport, NY)

1998-08-11T23:59:59.000Z

391

A finite difference method for studying thermal deformation in a 3D thin film exposed to ultrashort pulsed lasers  

E-Print Network [OSTI]

temperature and strain rate, as well as for the hot electron-blast effect in momentum transfer. In particular- pling effect between lattice temperature and strain rate, as well as for the hot electron-blast effect and implicit finite difference schemes on a staggered mesh. It accounts for the coupling effect between lattice

Melnik, Roderick

392

Multigrid Method for a Global Hall Conductor in the Earth's Ionosphere  

E-Print Network [OSTI]

with those in the interior of the domain is separated with a special boundary condition. The finite element: gyrotropic transfer, Hall conductivity, symmetrization, elliptic equation, varia­ tional principle, finite elements, multigrid method 1 Introduction Mathematical models of ionospherical electric field are boundary

393

Finite density phase transition of QCD with N{sub f}=4 and N{sub f}=2 using canonical ensemble method  

SciTech Connect (OSTI)

In a progress toward searching for the QCD critical point, we study the finite density phase transition of N{sub f}=4 and 2 lattice QCD at finite temperature with the canonical ensemble approach. We develop a winding number expansion method to accurately project out the particle number from the fermion determinant which greatly extends the applicable range of baryon number sectors to make the study feasible. Our lattice simulation was carried out with the clover fermions and improved gauge action. For a given temperature, we calculate the baryon-chemical potential from the canonical approach to look for the mixed phase as a signal for the first-order phase transition. In the case of N{sub f}=4, we observe an 'S-shape' structure in the chemical potential-density plane due to the surface tension of the mixed phase in a finite volume which is a signal for the first-order phase transition. We use the Maxwell construction to determine the phase boundaries for three temperatures below T{sub c}. The intersecting point of the two extrapolated boundaries turns out to be at the expected first-order transition point at T{sub c} with {mu}=0. This serves as a check for our method of identifying the critical point. We also studied the N{sub f}=2 case, but do not see a signal of the mixed phase for temperature as low as 0.83T{sub c}.

Li Anyi [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States) and Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Alexandru, Andrei [Physics Department, George Washington University, Washington, D.C. 20052 (United States); Liu, Keh-Fei [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States); Meng Xiangfei [Department of Physics, Nankai University, Tianjin 300071 (China); National Supercomputing Center, Tianjin 300457 (China)

2010-09-01T23:59:59.000Z

394

Method of pressurizing and stabilizing rock by periodic and repeated injections of a settable fluid of finite gel strength  

DOE Patents [OSTI]

A finite region of overpressure can be created in solid underground formations by the periodic injection of a fluid that has finite gel strength that subsequently, after each injection, partially sets--i.e., equivalently becomes a very much stronger gel. A region of overpressure is a region in which the static, locked in pressure is larger than what was there before. A region of overpressure can be used to prevent a roof of a tunnel from caving by adding compressive stresses in the roof. A sequence of regions of overpressure can be used to lift an arch or dome underground, squeeze off water or gas flows, stabilize dams, foundations, large underground rooms, etc. In general, the stress or pressure distribution in rock can be altered and engineered in a fashion that is more advantageous than what would have been the case without overstressing. 3 figs.

Colgate, S.A.

1983-01-25T23:59:59.000Z

395

Method of manufacturing iron aluminide by thermomechanical processing of elemental powders  

DOE Patents [OSTI]

A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

Deevi, Seetharama C. (Midlothian, VA); Lilly, Jr., A. Clifton (Chesterfield, VA); Sikka, Vinod K. (Oak Ridge, TN); Hajaligol, Mohammed R. (Richmond, VA)

2000-01-01T23:59:59.000Z

396

A Moving Mesh Numerical Method for Hyperbolic Conservation Laws  

E-Print Network [OSTI]

Aug 3, 2005 ... 173 (Jan., 1986), 59-69. ... PAGES 59-69 ..... S. F. DAVIS & J. E. FLAHERTY, An adaptive finite element method for initial-value problems for.

397

Key Elements of Robustness in Binary Black Hole Evolutions using Spectral Methods  

E-Print Network [OSTI]

As a network of advanced-era gravitational wave detectors is nearing its design sensitivity, efficient and accurate waveform modeling becomes more and more relevant. Understanding of the nature of the signal being sought can have an order unity effect on the event rates seen in these instruments. The paper provides a description of key elements of the Spectral Einstein Code ({\\tt SpEC}), with details of our spectral adaptive mesh refinement (AMR) algorithm that has been optimized for binary black hole (BBH) evolutions. We expect that the gravitational waveform catalog produced by our code will have a central importance in both the detection and parameter estimation of gravitational waves in these instruments.

Bela Szilagyi

2014-05-14T23:59:59.000Z

398

A measurement of the top quark mass with a matrix element method  

SciTech Connect (OSTI)

The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb{sup -1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t{bar t} and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb{sup -1} dataset they extract a top quark mass of 172.0 {+-} 2.6(stat) {+-} 3.3(syst) GeV/c{sup 2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c{sup 2} for m{sub t} = 178 GTeV/c{sup 2} and 3.1 GeV/c{sup 2} for m{sub t} = 172.5 GeV/c{sup 2}. The systematic error is dominated by the uncertainty of the jet energy scale.

Gibson, Adam Paul; /UC, Berkeley

2006-12-01T23:59:59.000Z

399

Passive electrically switchable circuit element having improved tunability and method for its manufacture  

DOE Patents [OSTI]

A resistive switching device and methods for making the same are disclosed. In the above said device, a resistive switching layer is interposed between opposing electrodes. The resistive switching layer comprises at least two sub-layers of switchable insulative material characterized by different ionic mobilities.

Mickel, Patrick R; James, Conrad D

2014-09-16T23:59:59.000Z

400

Parametric analysis of radiative-convective heat transfer around a circular cylinder in a cross flow using the finite volume radiation solution method  

SciTech Connect (OSTI)

In the outside vapor deposition (OVD) process, silica particles are deposited by thermophoretic force on the surface of a cylinder. This process is associated with complex physical phenomena such as heat transfer between a torch and a cylinder, chemical reaction for silica particle formation, and particle deposition. Since the OVD process is carried out in a very high temperature environment, radiative heat transfer should be taken into consideration. Here, the radiative-convective heat transfer around a circular cylinder in a cross flow of a radiating gas has been numerically analyzed using the finite volume radiation solution method in a nonorthogonal coordinate system. The cross-flow Reynolds number based on the cylinder diameter is 40, and the fluid Prandtl number is assumed to be 0.7. The radiative heat transfer coupled with convection is reasonably predicted by the finite volume radiation solution method. Distributions of the local Nusselt number are investigated according to the variation of radiation parameters such as conduction-to-radiation parameter, optical thickness, scattering albedo, and cylinder wall emissivity.

Lee, K.H.; Lee, J.S.; Choi, M. [Seoul National Univ. (Korea, Republic of). Dept. of Mechanical Engineering

1996-02-09T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Development of a failure prediction method for grout filled damaged tubular members  

E-Print Network [OSTI]

B ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF AN UNDENTED/UNGROUTED STEEL TUBULAR 86 APPENDIX C ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF AN UNDENTED/GROUTED STEEL TUBULAR 99 APPENDIX D ? ABAQUS INPUT FILE FOR FINITE ELEMENT... MODEL ?I 114 APPENDIX E ? ABAQUS INPUT FILE FOR FINITE ELEMENT MODEL //2 APPENDIX F - LISTING OF BUCKLE FORTRAN PROGRAM 122 130 APPENDIX G ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF A DENTED/GROUTED STEEL TUBULAR 135 VITA . . 157 Table...

Schank, Paul Edward

1993-01-01T23:59:59.000Z

402

Method for quantitative determination and separation of trace amounts of chemical elements in the presence of large quantities of other elements having the same atomic mass  

DOE Patents [OSTI]

Photoionization via autoionizing atomic levels combined with conventional mass spectroscopy provides a technique for quantitative analysis of trace quantities of chemical elements in the presence of much larger amounts of other elements with substantially the same atomic mass. Ytterbium samples smaller than 10 ng have been detected using an ArF* excimer laser which provides the atomic ions for a time-of-flight mass spectrometer. Elemental selectivity of greater than 5:1 with respect to lutetium impurity has been obtained. Autoionization via a single photon process permits greater photon utilization efficiency because of its greater absorption cross section than bound-free transitions, while maintaining sufficient spectroscopic structure to allow significant photoionization selectivity between different atomic species. Separation of atomic species from others of substantially the same atomic mass is also described.

Miller, C.M.; Nogar, N.S.

1982-09-02T23:59:59.000Z

403

A Characteristic Domain Decomposition and Space Time Local Refinement Method for  

E-Print Network [OSTI]

cause severe numerical difficulties [1­5]. Conventional finite difference or finite element methods­Lagrangian methods; linear hyperbolic problems; local refinement techniques I. INTRODUCTION First-order linear hyperbolic partial differential equations model the reactive transport of solutes in groundwater and surface

Sharpley, Robert

404

Electronic devices containing switchably conductive silicon oxides as a switching element and methods for production and use thereof  

DOE Patents [OSTI]

In various embodiments, electronic devices containing switchably conductive silicon oxide as a switching element are described herein. The electronic devices are two-terminal devices containing a first electrical contact and a second electrical contact in which at least one of the first electrical contact or the second electrical contact is deposed on a substrate to define a gap region therebetween. A switching layer containing a switchably conductive silicon oxide resides in the the gap region between the first electical contact and the second electrical contact. The electronic devices exhibit hysteretic current versus voltage properties, enabling their use in switching and memory applications. Methods for configuring, operating and constructing the electronic devices are also presented herein.

Tour, James M; Yao, Jun; Natelson, Douglas; Zhong, Lin; He, Tao

2013-11-26T23:59:59.000Z

405

A finite difference method for studying thermal deformation in a thin film exposed to ultrashort-pulsed lasers  

E-Print Network [OSTI]

between lattice temperature and strain rate, as well as for the hot-electron-blast effect in momentum-pulsed lasers. The method is obtained based on the parabolic two-step model. It accounts for the coupling effect

Melnik, Roderick

406

Elements & Compounds Atoms (Elements)  

E-Print Network [OSTI]

#12;Elements & Compounds #12;Atoms (Elements) Molecules (Compounds) Cells Elements & Compounds #12 #12;First shell Second shell Third shell Hydrogen 1H Lithium 3Li Sodium 11Na Beryllium 4Be Magnesium energy Higher energy (a) A ball bouncing down a flight of stairs provides an analogy for energy levels

Frey, Terry

407

Finite element analysis of shells with layers  

E-Print Network [OSTI]

It is well established that thin shell structures frequently feature narrow bands of strain concentration and localized displacement irregularities referred to as boundary and internal layers. It is crucial to capture these ...

Hiller, Jean-Franois, 1974-

2002-01-01T23:59:59.000Z

408

Hierarchical strategy for rapid finite element analysis  

E-Print Network [OSTI]

A new methodology is introduced where the natural hierarchical character of model descriptions and simulation results are exploited to expedite analysis of problems. The philosophy and the different concepts involved are illustrated by implementing...

Varghese, Julian

2004-09-30T23:59:59.000Z

409

Finite element approximation of coupled seismic and ...  

E-Print Network [OSTI]

GH are ice-like structures within the pore space that cause strong changes in ..... solved employing absorbing boundary conditions at the artificial boundaries.

410

A new finite element lifting surface technique  

E-Print Network [OSTI]

~ ~ ~ ~ ~ ~ ~ ~ ~ 34 VITA 39 vi LIST OF FIGURES Figure Page 1. Planar Panel Idealization 13 2. Vortex-Box Lifting Surface Model 14 3. Vortex-Box Trailing Wake Model 4. Spanwise Distribution Of Circulation, Planar Wing 5. Chordwise Distribution Of Circulation... coordinate ? ~ circulation strength, ft /sec 2 p ~ freestream density, slugs/ft 3 o a portion of S and W velocity potential, ft /sec 2 Subscripts a, b, c points in Cartesian space i, g indicies n ~ direction normal to a surface x, y, z with respect...

Kocurek, James David

1973-01-01T23:59:59.000Z

411

Finite element simulation of electrorheological fluids  

E-Print Network [OSTI]

Electrorheological (ER) fluids change their flow properties dramatically when an electric field is applied. These fluids are usually composed of dispersions of polarizable particles in an insulating base fluid or composed ...

Rhyou, Chanryeol, 1973-

2005-01-01T23:59:59.000Z

412

Finite Element Approximation of Coupled Seismic and ...  

E-Print Network [OSTI]

numerical approximation of coupled seismic and electromagnetic waves in 2D bounded fluid- saturated porous media, with absorbing boundary conditions at...

2009-02-15T23:59:59.000Z

413

DOMAIN DECOMPOSITION FOR A MIXED FINITE ELEMENT ...  

E-Print Network [OSTI]

... porous media, where highly discontinuous conductivity coefficients are also ...... [14] B. Smith, P. Bjrstad, and W. Gropp, Domain Decomposition, Cambridge

SIAM (#1) 1035 2001 Apr 10 12:32:38

2003-03-12T23:59:59.000Z

414

Construction of Higher Order Finite Element with  

E-Print Network [OSTI]

: intersection of null spaces of rules. Linear inequality in integers, gives as many un­ knowns as equations as generating polynomial ideal Solutions depend only on ideal, not particular generator set. Gr#bner basis: generator for polynomial ideal (Buchberger). 7 #12; ' & $ % Fgb algorithm Buchberger's algorithm

Kern, Michel

415

An AMR Capable Finite Element Diffusion Solver  

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 Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site Sustainabilityupgraded x-rayopticalAMR

416

Finite element modeling of syntactic foam.  

SciTech Connect (OSTI)

A decomposition model has been developed to predict the response of removable syntactic foam (RSF) exposed to fire-like heat fluxes. RSF consists of glass micro-balloons (GMB) in a cured epoxy polymer matrix. A chemistry model is presented based on the chemical structure of the epoxy polymer, mass transport of polymer fragments to the bulk gas, and vapor-liquid equilibrium. Thermophysical properties were estimated from measurements. A bubble nucleation, growth, and coalescence model was used to describe changes in properties with the extent of reaction. Decomposition of a strand of syntactic foam exposed to high temperatures was simulated.

Hobbs, Michael L.

2004-10-01T23:59:59.000Z

417

A General Methodology for Introducing Structured Nonorthogonal Grids into High-Order Finite-Difference Time-Domain Methods  

E-Print Network [OSTI]

. The method employs a coordinate transformation to map an arbitrary nonorthogonal structured grid onto transformation is used to map an arbitrary nonorthogonal structured grid onto a rectangular grid with uniformly rectangular grid can be used to carry out the time stepping. Generating a coordinate transformation to map one

418

GOMA - A full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport: User`s guide  

SciTech Connect (OSTI)

GOMA is a two- and three-dimensional finite element program which excels in analyses of manufacturing processes, particularly those involving free or moving interfaces. Specifically, the full-Newton-coupled heat, mass, momentum, and pseudo-solid mesh motion algorithm makes GOMA ideally suited for simulating processes in which the bulk fluid transport is closely coupled to the interfacial physics. Examples include, but are not limited to, coating and polymer processing flows, soldering, crystal growth, and solid-network or solution film drying. The code is based on the premise that any boundary can be (1) moving or free, with an apriori unknown position dictated by the distinguishing physics, (2) fixed, according to a global analytical representation, or (3) moving in time and space under user-prescribed kinematics. The goal is to enable the user to predict boundary position or motion simultaneously with the physics of the problem being analyzed and to pursue geometrical design studies and fluid-structure interaction problems. The moving mesh algorithm treats the entire domain as a computational Lagrangian solid that deforms subject to the physical principles which dictate boundary position. As an added benefit, the same Lagrangian solid mechanics can be exploited to solve multi-field problems for which the solid motion and stresses interact with other transport phenomena, either within the same material phase (e.g. shrinking coating) or in neighboring material phases (e.g. flexible blade coating). Thus, analyses of many fluid-structure interaction problems and deformable porous media problems are accessible. This document serves as a user`s guide and reference for GOMA and provides a brief overview of GOMA`s capabilities, theoretical background, and classes of problems for which it is targeted.

Schunk, P.R.; Sackinger, P.A.; Rao, R.R. [and others] [and others

1996-01-01T23:59:59.000Z

419

A Measurement of the Top Quark Mass with the D0 Detector at s**(1/2) = 1.96-TeV using the Matrix Element Method  

SciTech Connect (OSTI)

Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.

Kroeninger, Kevin Alexander; /Bonn U.

2004-04-01T23:59:59.000Z

420

A Pliant Method for Anisotropic Mesh Generation Frank J. Bossen  

E-Print Network [OSTI]

elements conform well to the requested shape metric. The method appears particularly well suited to surface- ysis, heat transfer, fluid flow, electromagnetics, computer graphics, and other applications. It should interface that allows it to be used inside an adaptive finite element solver or in other contexts. allows

California at Berkeley, University of

Note: This page contains sample records for the topic "finite element method" 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

Introduction Positive finite rank . . .  

E-Print Network [OSTI]

Introduction Positive finite rank . . . Positive finite rank . . . Positive finite rank . . . ¯? I qixf1981@sxu.edu.cn #12;Introduction Positive finite rank . . . Positive finite rank . . . Positive finite rank . . . ¯? I K 12 19 £ ¶w« ' 4 ò ? 1 Introduction · In quantum mechanics, a quantum system

Li, Chi-Kwong

422

Sighting optics including an optical element having a first focal length and a second focal length and methods for sighting  

DOE Patents [OSTI]

Sighting optics include a front sight and a rear sight positioned in a spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus for a user images of the front sight and the target.

Crandall, David Lynn

2011-08-16T23:59:59.000Z

423

Root-cause analysis of the better performance of the coarse-mesh finite-difference method for CANDU-type reactors  

SciTech Connect (OSTI)

Recent assessment results indicate that the coarse-mesh finite-difference method (FDM) gives consistently smaller percent differences in channel powers than the fine-mesh FDM when compared to the reference MCNP solution for CANDU-type reactors. However, there is an impression that the fine-mesh FDM should always give more accurate results than the coarse-mesh FDM in theory. To answer the question if the better performance of the coarse-mesh FDM for CANDU-type reactors was just a coincidence (cancellation of errors) or caused by the use of heavy water or the use of lattice-homogenized cross sections for the cluster fuel geometry in the diffusion calculation, three benchmark problems were set up with three different fuel lattices: CANDU, HWR and PWR. These benchmark problems were then used to analyze the root cause of the better performance of the coarse-mesh FDM for CANDU-type reactors. The analyses confirm that the better performance of the coarse-mesh FDM for CANDU-type reactors is mainly caused by the use of lattice-homogenized cross sections for the sub-meshes of the cluster fuel geometry in the diffusion calculation. Based on the analyses, it is recommended to use 2 x 2 coarse-mesh FDM to analyze CANDU-type reactors when lattice-homogenized cross sections are used in the core analysis. (authors)

Shen, W. [Candu Energy Inc., 2285 Speakman Dr., Mississauga, ON L5B 1K (Canada)

2012-07-01T23:59:59.000Z

424

Methods and computer executable instructions for rapidly calculating simulated particle transport through geometrically modeled treatment volumes having uniform volume elements for use in radiotherapy  

DOE Patents [OSTI]

Methods and computer executable instructions are disclosed for ultimately developing a dosimetry plan for a treatment volume targeted for irradiation during cancer therapy. The dosimetry plan is available in "real-time" which especially enhances clinical use for in vivo applications. The real-time is achieved because of the novel geometric model constructed for the planned treatment volume which, in turn, allows for rapid calculations to be performed for simulated movements of particles along particle tracks there through. The particles are exemplary representations of neutrons emanating from a neutron source during BNCT. In a preferred embodiment, a medical image having a plurality of pixels of information representative of a treatment volume is obtained. The pixels are: (i) converted into a plurality of substantially uniform volume elements having substantially the same shape and volume of the pixels; and (ii) arranged into a geometric model of the treatment volume. An anatomical material associated with each uniform volume element is defined and stored. Thereafter, a movement of a particle along a particle track is defined through the geometric model along a primary direction of movement that begins in a starting element of the uniform volume elements and traverses to a next element of the uniform volume elements. The particle movement along the particle track is effectuated in integer based increments along the primary direction of movement until a position of intersection occurs that represents a condition where the anatomical material of the next element is substantially different from the anatomical material of the starting element. This position of intersection is then useful for indicating whether a neutron has been captured, scattered or exited from the geometric model. From this intersection, a distribution of radiation doses can be computed for use in the cancer therapy. The foregoing represents an advance in computational times by multiple factors of time magnitudes.

Frandsen, Michael W. (Helena, MT); Wessol, Daniel E. (Bozeman, MT); Wheeler, Floyd J. (Idaho Falls, ID)

2001-01-16T23:59:59.000Z

425

Simulation of eccentricity effects on short-and long-normal logging measurements using a Fourier-hp-finite-element method*  

E-Print Network [OSTI]

1 Korea Institute of Geoscience and Mineral Resources (KIGAM), Gwahang-no 92, Yuseong-gu, Daejeon matter of primary concern due to global warming. The main limitations of resistivity logging are due

Torres-Verdín, Carlos

426

15th Workshop on the Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields --Ulm, July 2008 Determining Effective Elasticity Parameters  

E-Print Network [OSTI]

is often affected by osteoporosis. Osteoporosis is characterized by low bone mass and the occurrence to osteoporosis [37]. The International Osteoporosis Foundation estimates direct costs of 31.7 billion Euro from

Rumpf, Martin

427

Pollution error in the h-version of the finite-element method and the local quality of a-posteriori error estimators  

E-Print Network [OSTI]

shown in Fig. 5. 1a, a = ?, p = 2 (2cr & p). 122 3' Table 5. 4a. Components of the energy-norm of the error in ~s. Square domain shown in Fig. 5. 2, smooth solution u(z?z, ) = A sin xz, sinh zzs, A=10s, p ? 2 127 Table 5. 4b. Pollution.... Pollution-effect for meshes refined locally in an interior subdomain. 4 Convex domain shown in Fig. 5. 7, a = ?, p = 2 (2cr & p) 131 xx Page Table 5. 5b. Pollution-efi'ect for meshes refined locally in an interior subdomain. Pollution factors p...

Mathur, Anuj

1994-01-01T23:59:59.000Z

428

A measurement of the top quark mass in 1.96 TeV proton-antiproton collisions using a novel matrix element method  

SciTech Connect (OSTI)

A measurement of the top quark mass in t{bar t} {yields} l + jets candidate events, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix elements techniques, the method involves an integration using the Standard Model matrix element for tt production and decay. however, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb{sup -1} data sample, using events with a high-p{sub T} lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M{sub meas} = 169.8 {+-} 2.3(stat.) {+-} 1.4(syst.) GeV/c{sup 2}.

Freeman, John C.; /LBL, Berkeley

2007-12-01T23:59:59.000Z

429

A Measurement of the Top Quark Mass in 1.96 TeV Proton-Antiproton Collisions Using a Novel Matrix Element Method  

SciTech Connect (OSTI)

A measurement of the top quark mass in t{bar t} {yields} l + jets candidate events, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t{bar t} production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb{sup -1} data sample, using events with a high-p{sub T} lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M{sub meas} = 169.8 {+-} 2.3(stat.) {+-} 1.4(syst.) GeV/c{sup 2}.

CDF Collaboration; Freeman, John; Freeman, John

2007-09-30T23:59:59.000Z

430

GLOBAL AND FINITE TERMINATION OF A TWO-PHASE ...  

E-Print Network [OSTI]

GLOBAL AND FINITE TERMINATION OF A TWO-PHASE. AUGMENTED LAGRANGIAN FILTER METHOD FOR. GENERAL QUADRATIC PROGRAMS?.

2007-06-12T23:59:59.000Z

431

NONLOCAL COMPUTATIONAL METHODS APPLIED TO COMPOSITE STRUCTURES  

E-Print Network [OSTI]

is developed. It consists in the use of nonlocal description of the material combined with an arc length constitutive equation sets can deal with damage growth. Using these equations, the finite elements method makes of tools which ensure a good balance between applicability to OMC structures (which exhibit an anisotropic

Boyer, Edmond

432

Peculiarities of a method for ex-reactor heating of electrodes and obtaining voltage-current characteristics of multi-cell thermionic fuel elements  

SciTech Connect (OSTI)

The paper discusses principle of operation and applications of a pulse method of heating multi-cell thermionic fuel elements. Some experimental results are given for a cylindrical single-cell thermionic energy converter that simulates conditions close to that of multi-cell TFE operation. Basic requirements for technical parameters are stated that should be observed when testing TFE on thermal facilities. The means to improve the method are described, including both a computer-aided experiment and modifications in individual components of the test facility. {copyright} {ital 1996 American Institute of Physics.}

Kalandarishvili, A.G. [Sukhumi Institute of Physics and Engineering, Tbilisi 380008 Republic of (Georgia); Drozdov, A.A. [RRC ``Kurchatov Institute``, Moscow 123182 (Russia); Stepennov, B.S. [INERTEK, Moscow 123182 (Russia)

1996-03-01T23:59:59.000Z

433

Programmatic Elements  

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

The Guide provides acceptable methods of meeting the requirements of DOE O 151.1C for programmatic elements that sustain the emergency management program and maintain the readiness of the program to respond to an emergency. Cancels DOE G 151.1-1, Volume 5-1, DOE G 151.1-1, Volume 5-2, DOE G 151.1-1, Volume 5-3, DOE G 151.1-1, Volume 5-4, DOE G 151.1-1, Volume 7-1, and DOE G 151.1-1, Volume 7-3.

2007-07-11T23:59:59.000Z

434

A Pliant Method for Anisotropic Mesh Generation Frank J. Bossen # Paul S. Heckbert +  

E-Print Network [OSTI]

elements conform well to the requested shape metric. The method appears particularly well suited to surface­ ysis, heat transfer, fluid flow, electromagnetics, computer graphics, and other applications. It should interface that allows it to be used inside an adaptive finite element solver or in other contexts. allows

California at Berkeley, University of

435

Probabilistic collocation method for unconfined flow in heterogeneous media Liangsheng Shi a,b,*, Jinzhong Yang a  

E-Print Network [OSTI]

-equa- tion method (Zhang, 2002), and the stochastic spectral finite element method (SSFEM) (Ghanem and Spanos in groundwater and solute transport problems. Recently, collocation methods have been studied and used-based methods lie on those deterministic numerical codes can be utilized directly in stochastic modeling

Zhang, Dongxiao

436

Spectral resolution for a five-element, filtered, x-ray detector array using the method of Backus and Gilbert  

SciTech Connect (OSTI)

The generalized method of Backus and Gilbert (BG) is described and applied to the inverse problem of obtaining the spectrum from a five-channel, filtered array of x-ray detectors. This diagnostic is routinely fielded on the Z facility at Sandia National Laboratories to study soft x-ray photons ({approx}100-2300 eV), emitted by high density Z-pinch plasmas. The BG method defines spectral resolution limits on the system of response functions that are in good agreement with a classical unfold method, based on a histogram representation of the source spectrum. The resolution so defined is independent of the source spectrum. For noise-free, simulated data the BG approximating function is also in reasonable agreement with the source spectrum (150 eV blackbody) and the unfolded spectrum. This function may be used as an initial trial function for iterative methods or a regularization model.(c) 2000 American Institute of Physics. (c)

Fehl, D. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States); Biggs, F. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States); Chandler, G. A. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States); Stygar, W. A. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States)

2000-08-01T23:59:59.000Z

437

Spectral Resolution for Five-Element, Filtered, X-Ray Detector (XRD) Arrays Using the Methods of Backus and Gilbert  

SciTech Connect (OSTI)

The generalized method of Backus and Gilbert (BG) is described and applied to the inverse problem of obtaining spectra from a 5-channel, filtered array of x-ray detectors (XRD's). This diagnostic is routinely fielded on the Z facility at Sandia National Laboratories to study soft x-ray photons ({le}2300 eV), emitted by high density Z-pinch plasmas. The BG method defines spectral resolution limits on the system of response functions that are in good agreement with the unfold method currently in use. The resolution so defined is independent of the source spectrum. For noise-free, simulated data the BG approximating function is also in reasonable agreement with the source spectrum (150 eV black-body) and the unfold. This function may be used as an initial trial function for iterative methods or a regularization model.

FEHL,DAVID LEE; BIGGS,F.; CHANDLER,GORDON A.; STYGAR,WILLIAM A.

2000-01-17T23:59:59.000Z

438

Method and system for laser-based formation of micro-shapes in surfaces of optical elements  

DOE Patents [OSTI]

A method of forming a surface feature extending into a sample includes providing a laser operable to emit an output beam and modulating the output beam to form a pulse train having a plurality of pulses. The method also includes a) directing the pulse train along an optical path intersecting an exposed portion of the sample at a position i and b) focusing a first portion of the plurality of pulses to impinge on the sample at the position i. Each of the plurality of pulses is characterized by a spot size at the sample. The method further includes c) ablating at least a portion of the sample at the position i to form a portion of the surface feature and d) incrementing counter i. The method includes e) repeating steps a) through d) to form the surface feature. The sample is free of a rim surrounding the surface feature.

Bass, Isaac Louis; Guss, Gabriel Mark

2013-03-05T23:59:59.000Z

439

Summary compilation of shell element performance versus formulation.  

SciTech Connect (OSTI)

This document compares the finite element shell formulations in the Sierra Solid Mechanics code. These are finite elements either currently in the Sierra simulation codes Presto and Adagio, or expected to be added to them in time. The list of elements are divided into traditional two-dimensional, plane stress shell finite elements, and three-dimensional solid finite elements that contain either modifications or additional terms designed to represent the bending stiffness expected to be found in shell formulations. These particular finite elements are formulated for finite deformation and inelastic material response, and, as such, are not based on some of the elegant formulations that can be found in an elastic, infinitesimal finite element setting. Each shell element is subjected to a series of 12 verification and validation test problems. The underlying purpose of the tests here is to identify the quality of both the spatially discrete finite element gradient operator and the spatially discrete finite element divergence operator. If the derivation of the finite element is proper, the discrete divergence operator is the transpose of the discrete gradient operator. An overall summary is provided from which one can rank, at least in an average sense, how well the individual formulations can be expected to perform in applications encountered year in and year out. A letter grade has been assigned albeit sometimes subjectively for each shell element and each test problem result. The number of A's, B's, C's, et cetera assigned have been totaled, and a grade point average (GPA) has been computed, based on a 4.0-system. These grades, combined with a comparison between the test problems and the application problem, can be used to guide an analyst to select the element with the best shell formulation.

Heinstein, Martin Wilhelm; Hales, Jason Dean (Idaho National Laboratory, Idaho Falls, ID); Breivik, Nicole L.; Key, Samuel W. (FMA Development, LLC, Great Falls, MT)

2011-07-01T23:59:59.000Z

440

Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II  

SciTech Connect (OSTI)

This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.

Wanty, R.B.; Langmuir, D.; Chatham, J.R.

1981-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Response Elements  

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

The Guide provides acceptable methods for meeting the requirement of DOE O 151.1C for response elements that respond or contribute to response as needed in an emergency. Cancels DOE G 151.1-1, Volume 3-1, DOE G 151.1-1, Volume 3-2, DOE G 151.1-1, Volume 3-3, DOE G 151.1-1, Volume 3-4, DOE G 151.1-1, Volume 4-1, DOE G 151.1-1, Volume 4-2, DOE G 151.1-1, Volume 4-3, DOE G 151.1-1, Volume 4-4, DOE G 151.1-1, Volume 4-5, and DOE G 151.1-1, Volume 4-6.

2007-07-11T23:59:59.000Z

442

A Generalized Finite Source Calibration Factor: A Natural Improvement to the Finite Source Correction Factor for Uranium Holdup Measurements  

SciTech Connect (OSTI)

This paper proposes refinements to the finite source correction factor used in holdup measurements. Specifically it focuses on a more general method to estimate the average detector response for a finite source. This proposed method for the average detector response is based directly on the Generalized Geometry Holdup (GGH) assay method. First, the finite source correction factor as originally proposed is reviewed in this paper. Following this review the GGH assay method is described. Lastly, a new finite area calibration factor based on GGH is then proposed for finite point and line sources. As an alternative to the direct use of the finite arca calibration factor, finite source correction factors are also derived from this calibration factor. This new correction factor can be used in a manner similar to the finite source correction factor as currently implemented.

Gunn, C.A.; Oberer, R.B.; chiang, L.G.; Ceo, R.N.

2003-01-28T23:59:59.000Z

443

A Finite Landscape?  

E-Print Network [OSTI]

We present evidence that the number of string/$M$ theory vacua consistent with experiments is a finite number. We do this both by explicit analysis of infinite sequences of vacua and by applying various mathematical finiteness theorems.

Bobby S Acharya; Michael R Douglas

2006-06-21T23:59:59.000Z

444

Method of generating a surface mesh  

DOE Patents [OSTI]

A method and machine-readable medium provide a technique to generate and modify a quadrilateral finite element surface mesh using dual creation and modification. After generating a dual of a surface (mesh), a predetermined algorithm may be followed to generate and modify a surface mesh of quadrilateral elements. The predetermined algorithm may include the steps of generating two-dimensional cell regions in dual space, determining existing nodes in primal space, generating new nodes in the dual space, and connecting nodes to form the quadrilateral elements (faces) for the generated and modifiable surface mesh.

Shepherd, Jason F. (Albuquerque, NM); Benzley, Steven (Provo, UT); Grover, Benjamin T. (Tracy, CA)

2008-03-04T23:59:59.000Z

445

System and method for implementing periodic early discard in on-chip buffer memories of network elements  

DOE Patents [OSTI]

An advance is made over the prior art in accordance with the principles of the present invention that is directed to a new approach for a system and method for a buffer management scheme called Periodic Early Discard (PED). The invention builds on the observation that, in presence of TCP traffic, the length of a queue can be stabilized by selection of an appropriate frequency for packet dropping. For any combination of number of TCP connections and distribution of the respective RTT values, there exists an ideal packet drop frequency that prevents the queue from over-flowing or under-flowing. While the value of the ideal packet drop frequency may quickly change over time and is sensitive to the series of TCP connections affected by past packet losses, and most of all is impossible to compute inline, it is possible to approximate it with a margin of error that allows keeping the queue occupancy within a pre-defined range for extended periods of time. The PED scheme aims at tracking the (unknown) ideal packet drop frequency, adjusting the approximated value based on the evolution of the queue occupancy, with corrections of the approximated packet drop frequency that occur at a timescale that is comparable to the aggregate time constant of the set of TCP connections that traverse the queue.

Francini, Andrea

2013-05-14T23:59:59.000Z

446

Investigation on the co-precipitation of transuranium elements from alkaline solutions by the method of appearing reagents  

SciTech Connect (OSTI)

Highly alkaline radioactive waste solutions originating from production of plutonium for military purposes are stored in underground tanks at the U.S. Department of Energy Hanford Site. The purification of alkaline solutions from neptunium and plutonium is important in the treatment and disposal of these wastes. This report describes scoping tests with sodium hydroxide solutions, where precipitation techniques were investigated to perform the separation. Hydroxides of iron (III), manganese (II), cobalt (II, III), and chromium (III); manganese (IV) oxide, and sodium uranate were investigated as carriers. The report describes the optimum conditions that were identified to precipitate these carriers homogeneously throughout the solution by reductive, hydrolytic, or catalytic decomposition of alkali-soluble precursor compounds by a technique called the Method of Appearing Reagents. The coprecipitation of pentavalent and hexavalent neptunium and plutonium was investigated for the candidate agents under optimum conditions and is described in this report along with the following results. Plutonium coprecipitated well with all tested materials except manganese (IV) oxide. Neptunium only coprecipitated well with uranate. The report presents a hypothesis to explain these behaviors. Further tests with more complex solution matrices must be performed.

Krot, N.; Shilov, V.; Bessonov, A.; Budantseva, N.; Charushnikova, I.; Perminov, V.; Astafurova, L. [Russian Academy of Science (Russian Federation). Inst. of Physical Chemistry

1996-06-06T23:59:59.000Z

447

Modeling of optical amplifier waveguide based on silicon nanostructures and rare earth ions doped silica matrix gain media by a finite-difference time-domain method: comparison of achievable gain with Er3+ or Nd3+ ions dopants  

E-Print Network [OSTI]

A comparative study of the gain achievement is performed in a waveguide optical amplifier whose active layer is constituted by a silica matrix containing silicon nanograins acting as sensitizer of either neodymium ions (Nd 3+) or erbium ions (Er 3+). Due to the large difference between population levels characteristic times (ms) and finite-difference time step (10 --17 s), the conventional auxiliary differential equation and finite-difference time-domain (ADE-FDTD) method is not appropriate to treat such systems. Consequently, a new two loops algorithm based on ADE-FDTD method is presented in order to model this waveguide optical amplifier. We investigate the steady states regime of both rare earth ions and silicon nanograins levels populations as well as the electromagnetic field for different pumping powers ranging from 1 to 10 4 mW.mm-2. Furthermore, the three dimensional distribution of achievable gain per unit length has been estimated in this pumping range. The Nd 3+ doped waveguide shows a higher gross...

Cardin, Julien; Dufour, Christian; Gourbilleau, Fabrice

2015-01-01T23:59:59.000Z

448

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2011; 00:123  

E-Print Network [OSTI]

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2011; 00 for the treatment of discontinuous pressures in multi­fluid flows Roberto F. Ausas1 , Gustavo C. Buscaglia1 WORDS: Multi­fluids, Two­phase flows, Embedded interfaces, Finite element method, Surface tension

Buscaglia, Gustavo C.

449

Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State  

SciTech Connect (OSTI)

The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb{sup -1} of D0 Run II data, the mass of the top quark is measured to be: m{sub top}{sup {ell}+jets} = 169.5 {+-} 4.4(stat. + JES){sub -1.6}{sup +1.7}(syst.) GeV; m{sub top}{sup e+jets} = 168.8 {+-} 6.0(stat. + JES){sub -1.9}{sup +1.9}(syst.) GeV; m{sub top}{sup {mu}+jets} = 172.3 {+-} 9.6(stat.+JES){sub -3.3}{sup +3.4}(syst.) GeV. The jet energy scale measurement in the {ell}+jets sample yields JES = 1.034 {+-} 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

Schieferdecker, Philipp; /Munich U.; ,

2005-08-01T23:59:59.000Z

450

Efficient double beta decay nuclear matrix elements computations  

SciTech Connect (OSTI)

We have developed a shell model code for the accurate computation of the two-body matrix elements of the transition operators involved in the neutrinoless double beta decay. This code features coupled cluster method short-range correlations with Jastrow-like functions, finite nucleon size effect and higher order nucleon current corrections. We present the results obtained for {sup 48}Ca and {sup 82}Se, then we compare them with other results in the literature. In the case of {sup 48}Ca, we also study the contributions of the included effects and find good agreement with other published results.

Neacsu, Andrei [Horia Hulubei Foundation (FHH) 407 Atomistilor, Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH) 30 Reactorului, Magurele-Bucharest 077125 (Romania)

2012-11-20T23:59:59.000Z

451

Low-Order Mathematical Modelling of Electric Double Layer Supercapacitors Using Spectral Methods  

E-Print Network [OSTI]

This work investigates two physics-based models that simulate the non-linear partial differential algebraic equations describing an electric double layer supercapacitor. In one model the linear dependence between electrolyte concentration and conductivity is accounted for, while in the other model it is not. A spectral element method is used to discretise the model equations and it is found that the error convergence rate with respect to the number of elements is faster compared to a finite difference method. The increased accuracy of the spectral element approach means that, for a similar level of solution accuracy, the model simulation computing time is approximately 50% of that of the finite difference method. This suggests that the spectral element model could be used for control and state estimation purposes. For a typical supercapacitor charging profile, the numerical solutions from both models closely match experimental voltage and current data. However, when the electrolyte is dilute or where there is...

Drummond, Ross; Duncan, Stephen R

2014-01-01T23:59:59.000Z

452

Matrix elements for type 1 unitary irreducible representations of the Lie superalgebra gl(m|n)  

SciTech Connect (OSTI)

Using our recent results on eigenvalues of invariants associated to the Lie superalgebra gl(m|n), we use characteristic identities to derive explicit matrix element formulae for all gl(m|n) generators, particularly non-elementary generators, on finite dimensional type 1 unitary irreducible representations. We compare our results with existing works that deal with only subsets of the class of type 1 unitary representations, all of which only present explicit matrix elements for elementary generators. Our work therefore provides an important extension to existing methods, and thus highlights the strength of our techniques which exploit the characteristic identities.

Gould, Mark D.; Isaac, Phillip S.; Werry, Jason L. [School of Mathematics and Physics, The University of Queensland, St Lucia, QLD 4072 (Australia)] [School of Mathematics and Physics, The University of Queensland, St Lucia, QLD 4072 (Australia)

2014-01-15T23:59:59.000Z

453

Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method  

E-Print Network [OSTI]

A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5 inverse femtobarns collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8 TeV. In order to separate the signal from the larger ttbar+jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, mu, relative to the standard model prediction for a Higgs boson mass of 125 GeV. The observed (expected) exclusion limit at a 95% confidence level is mu a best fit value mu-hat = 1.2+1.6-1.5.

CMS Collaboration

2015-02-09T23:59:59.000Z

454

Neutronic fuel element fabrication  

DOE Patents [OSTI]

This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure by encompassing the sides of the fuel element between the header plates.

Korton, George (Cincinnati, OH)

2004-02-24T23:59:59.000Z

455

High-resolution wave-theory-based ultrasound reflection imaging using the split-step fourier and globally optimized fourier finite-difference methods  

DOE Patents [OSTI]

Methods for enhancing ultrasonic reflection imaging are taught utilizing a split-step Fourier propagator in which the reconstruction is based on recursive inward continuation of ultrasonic wavefields in the frequency-space and frequency-wave number domains. The inward continuation within each extrapolation interval consists of two steps. In the first step, a phase-shift term is applied to the data in the frequency-wave number domain for propagation in a reference medium. The second step consists of applying another phase-shift term to data in the frequency-space domain to approximately compensate for ultrasonic scattering effects of heterogeneities within the tissue being imaged (e.g., breast tissue). Results from various data input to the method indicate significant improvements are provided in both image quality and resolution.

Huang, Lianjie

2013-10-29T23:59:59.000Z

456

A Method to Increase Current Density in a Mono Element Internal Tin Processed Superconductor Utilizing Zr Oxide to Refine Grain Size  

SciTech Connect (OSTI)

The effect of Oxygen on (Nb1Zr)3Sn multifilament conductors manufactured by the Mono Element Internal Tin (MEIT) process was explored to improve the current density by refining the grain size. This followed work first done by General Electric on the Nb3Sn tape process. Techniques to fabricate the more difficult Nb1Zr composites are described and allowed fabrication of long lengths of .254 mm diameter wire from an 88.9 mm diameter billet. Oxygen was incorporated through the use of SnO2 mixed with tin powder and incorporated into the core. These were compared to samples with Ti+Sn and Cu+Sn cores. Heat treatments covered the range of 700 C to 1000 C. Current density vs. H, grain size, and reaction percentages are provided for the materials tested. The Oxygen gave superior results in the temperature range of 815-1000 C. It also stabilized the filament geometry of the array in comparison to the other additions at the higher temperatures. At 815 C a peak in layer Jc yielded values of 2537 A/mm2 at 12 T and 1353 A/mm2 at 15T, 8-22% and 30-73% greater respectively than 700 C values. Results with Oxygen at high temperature show the possibility of high speed continuous reaction of the composite versus the current batch or react in place methods. In general the Ti additions gave superior results at the lower reaction temperature. Future work is suggested to determine if the 815 C reaction temperature can lead to higher current density in high tin (Nb1Zr+Ox)3Sn conductors. A second technique incorporated oxygen directly into the Nb1Zr rods through heat treatment with Nb2O5 at 1100 C for 100 hours in vacuum prior to extrusion. The majority of the filaments reduced properly in the composite but some local variations in hardness led to breakage at smaller diameters.

Bruce A. Zeitlin, Eric Gregory

2008-04-07T23:59:59.000Z

457

TOWARDS AN FVEFAC METHOD FOR DETERMINING THERMOCAPILLARY EFFECTS ON WELD POOL SHAPE  

E-Print Network [OSTI]

the liquid free surface flat. The numerical method proposed for this problem utilizes a finite volume element [2] showed how vigorous ther­ mocapillary convection can lead to localized intense heat transfer. The present work examines how this localized heat transfer modifies the shape of the solid­liquid interface

458

Monte Carlo Methods for Uncertainty Quantification Mathematical Institute, University of Oxford  

E-Print Network [OSTI]

Lecture 1: Introduction and Monte Carlo basics some model applications random number generation Monte force being outside some specified range Note: if we turn this into a full finite element analysis on the boundary. Mike Giles (Oxford) Monte Carlo methods October 25, 2013 7 / 28 #12;Application 3 In modelling

Giles, Mike

459

Monte Carlo Methods for Uncertainty Quantification Mathematical Institute, University of Oxford  

E-Print Network [OSTI]

methods October 25, 2013 7 / 28 Application 3 In modelling groundwater flow in nuclear waste repositories: Introduction and Monte Carlo basics some model applications random number generation Monte Carlo estimation specified range Note: if we turn this into a full finite element analysis, then the computational cost

Giles, Mike

460

Numerical methods for the simulation of salt migration in regional groundwater  

E-Print Network [OSTI]

Numerical methods for the simulation of salt migration in regional groundwater flow E.S. van Baaren #12;Contents 1 Introduction 1 2 Model description 3 2.1 Basic Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2 Finite Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.2.1 Grid

Vuik, Kees

Note: This page contains sample records for the topic "finite element method" 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

Finite Element Analysis of Three-Phase Piezoelectric Nanocomposites  

E-Print Network [OSTI]

on performance. The nanocomposite consisted of a polyimide matrix, beta-CN APB/ODPA, enhanced with single wall carbon nanotubes and PZT-5A particles. The polyimide and nan- otube phases were modeled as a single homogenized phase. This results in a two...

Maxwell, Kevin S.

2010-10-12T23:59:59.000Z

462

One dimensional electroseismic modeling using the finite element ...  

E-Print Network [OSTI]

... and Campanella, O., Characterization of frozen orange juice by ultrasound and wavelet analysis, to appear in Journal of the. Science of Food and Agriculture...

2013-01-30T23:59:59.000Z

463

Finite element modeling of SHTE and PSVTM electroseismics  

E-Print Network [OSTI]

(kinetic) energy. The electroseismic equations linking ...... located centered with respect to the x-axis and on the soil surface. The com- putational domain has 3...

zyserman

464

Finite element analysis of a coiled composite tubular  

E-Print Network [OSTI]

This study presents the design and stress analysis of a composite tubular that can be coiled onto large spools for ease of storage and installation on offshore platforms. The tube is analyzed under working pressure and tensile loads, as well...

Judice, David Roy

2012-06-07T23:59:59.000Z

465

Computational wind engineering using finite element package ADINA  

E-Print Network [OSTI]

Design of tall and long span structures is governed by the wind forces. Inadequate research in the field of wind dynamics has forced engineers to rely on design codes or wind tunnel tests for sufficient data. The present ...

Bajoria, Ankur

2008-01-01T23:59:59.000Z

466

Numerical Exercises Course Applied Finite Elements 2012 Tsunami Wave Amplification  

E-Print Network [OSTI]

waves seen on our car window as ripples on water sheets during heavy rain are also shallow water waves-Dimensional Linear Shallow Water Equations Linear shallow water equations (LSWE) describe the the motion of waves travelling on the free surface of a liquid, such as sea water. They govern the motion of small

Al Hanbali, Ahmad

467

Flexible finite-element modeling of global geomagnetic depth sounding  

E-Print Network [OSTI]

also like to thank Steven Constable, Alexei Kuvshinov, andand Bob Parker and Steven Constable for useful discussions.Randolph E. Bank Steven C. Constable Jeffrey S. Gee Robert

Ribaudo, Joseph Thomas

2011-01-01T23:59:59.000Z

468

ECI 212A: Finite Element Procedures in Applied Mechanics  

E-Print Network [OSTI]

Press, Boca Raton, FL, 2006. #12;Winter 2014 ECI 212A Instructor: N. Sukumar 2. T. J. R. Hughes (1987

Schladow, S. Geoffrey

469

Heat Transport in Groundwater Systems--Finite Element Model  

E-Print Network [OSTI]

into groundwater aquifers for long term energy storage. Analytical solutions are available that predict water temperatures as hot water is injected into a groundwater aquifer, but little field and laboratory data are available to verify these models. The objectives...

Grubaugh, E. K.; Reddell, D. L.

470

Finite element modeling of SHTE and PSVTM electroseismics  

E-Print Network [OSTI]

Article history: Received 8 January ... partially saturated gas regions are presented. ...... homogeneous layer of water-saturated poorly permeable shale; the.

Fabio I. Zyserman

2010-10-07T23:59:59.000Z

471

Least-squares finite elements and constrained evolution systems  

E-Print Network [OSTI]

D(CA) ? D( AC) ? X such that CAx = ACx for all x ? D. WithD is dense in D( C), and CAx = 0 = ACx for all x ? D. Thus,

Szypowski, Ryan

2008-01-01T23:59:59.000Z

472

FINITE ELEMENT ANALYSIS OF STEEL WELDED COVERPLATE INCLUDING COMPOSITE DOUBLERS  

E-Print Network [OSTI]

With the increasing focus on welded bridge members resulting in crack initiation and propagation, there is a large demand for creative solutions. One of these solutions includes the application of composite doublers over the critical weld. In order...

Petri, Brad

2008-05-15T23:59:59.000Z

473

Blank optimization in sheet metal forming using finite element simulation  

E-Print Network [OSTI]

The present study aims to determine the optimum blank shape design for the deep drawing of arbitrary shaped cups with a uniform trimming allowance at the flange i.e. cups without ears. This earing defect is caused by planar anisotropy in the sheet...

Goel, Amit

2006-04-12T23:59:59.000Z

474

FINITE ELEMENT SIMULATION OF MACROSCOPIC MACHINING PROCESSES -IMPLEMENTATION OF TIME  

E-Print Network [OSTI]

force and heat flux prediction is triggered that calculates the mechanical and thermal load. It is modeled mathematically by linking heat con- duction equation with the deformation equation on a time with a process model for prediction of cutting forces and heat flux, thermal and mechanical effects during

Schmidt, Alfred

475

ARTICLE IN PRESS Finite Elements in Analysis and Design ( )  

E-Print Network [OSTI]

& Resource Engineering, The University of Western Australia, Crawley Western Australia 6009, Australia

Augarde, Charles

476

Finite element modeling of hydraulic fracturing in 3D  

E-Print Network [OSTI]

Mar 22, 2013 ... tion of hydrofracture properties using signals from hydraulic pumps. J. Pet. Sci. ... A.. Touzelet. S.: Tracer testing of the geothermal heat ex-.

2013-03-22T23:59:59.000Z

477

Parallel finite element modeling of earthquake ground response and liquefaction  

E-Print Network [OSTI]

Machines Corporation (IBM). Arduino, P. , Kramer, S. , and2000; Shao and Desai 2000; Arduino et al. 2001). Currently,

Lu, Jinchi

2006-01-01T23:59:59.000Z

478

Finite element based micromechanical modeling of periodic composite microstructures  

E-Print Network [OSTI]

The mechanical behavior of cellular solids, including stiffness and strength, can be tuned by tailoring the underlying geometry and material constituents of the microstructure. Here the effect of key parameters on the ...

Rosario, Matthew J

2010-01-01T23:59:59.000Z

479

Finite-element harmonic experiments to model fractured induced ...  

E-Print Network [OSTI]

Mar 10, 2014 ... Fractured hydrocarbon reservoirs have been the subject of interest in ...... size. Once a continuous fractal distribution of brine is obtained over...

santos

480

The Uranium Processing Facility Finite Element Meshing Discussion  

Office of Environmental Management (EM)

* Discuss the mesh criteria * Discuss the evolution of the mesh of the UPF main building model * Discuss how the mesh affects the analysis process October 25, 2011 2 Department of...

Note: This page contains sample records for the topic "finite element method" 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

Finite element modeling of heat and mass transport in aquifers  

E-Print Network [OSTI]

1s written as v [ ' ( ? + pg ? )] + 0 = (o + ep a ) ? + ez a ? !I) kxi o ap aT ax, ax; o p at o T at where kx. 1 Po Bp 9T intr1nsic permeab1lity in the x. direct1on, L ; 2. 1 fluid density, M L -2. fluid dynamic v1scos1ty, FTL 2 -l... The basis functions used here are presented in Table 1. These functions fulfill both the compatibility and completeness requirements Linear Nodes le 5r lo Quadratic Nodes 13 I 820 9 I I l7 J Ig ~ I8 l4 19 23 24 Cubic Nodes 37 38 30 39 743...

Grubaugh, Elston Kent

1980-01-01T23:59:59.000Z

482

Finite Element Analysis of Piezoelectric Ceramic Speaker with Ansys Software  

E-Print Network [OSTI]

used. For many kinds of piezoelectric ceramic vibration, equivalent electric circuit analysis, such as Mason equivalent electric circuit analysis and Krimholtz equivalent electric circuit analysis,is a kind requirements, piezoelectric speaker also has been a leap development. Among the vibration mode, the bending

Wang, Ji

483

A Mixed Finite Element Framework for Modeling Coupled Fluid Flow ...  

E-Print Network [OSTI]

such as recovery from compaction drive, waterflooding, surface subsidence, seal in- tegrity ...... and for rocks and concrete it is in the range of 0.4-0.6. ...... incorporate into the programs an automatic, self-adaptive, procedure which adjusts.

Birendra Jha

2005-10-03T23:59:59.000Z

484

THERMAL PROPERTY PREDICTION VIA FINITE-ELEMENT SIMULATIONS  

E-Print Network [OSTI]

of gas turbine parts Optimization of k during TBC material development New lower k TBC materials materials development effort in industry has been to produce more reliable and reproducible TBC's. Knowing in advanced turbine airfoil design to allow more precise part temperature and life assessment. As physical

Fuller, Edwin R.

485

Least-squares finite elements and constrained evolution systems  

E-Print Network [OSTI]

in?nitesimal) generator of T is the linear operator A : D(and Generators Let X be a Banach space with norm X , A : D(A) ? X ? X be a lineara linear operator. Then, A is the in?nitesimal generator of

Szypowski, Ryan

2008-01-01T23:59:59.000Z

486

Finite Element Modeling of the Fastening Systems and the Concrete  

E-Print Network [OSTI]

Sleeper and Ballast 0 500 1000 1500 2000 2500 3000 3500 4000 0.0000 0.0002 0.0004 0.0006 0.0008 0 of strands Rail seat area is between 0.39 m to 0.67 m Rail Seat Area Component Modeling: Concrete Sleeper Seat Area Position of concrete surface strain lt = 0.48 m Component Modeling: Concrete Sleeper

Barkan, Christopher P.L.

487

Finite Element Studies of Colloidal Mixtures Influenced by Electric Fields  

E-Print Network [OSTI]

.2 micrometers, 40 micrometers, and 90 micrometers from the gap center. Total force vectors were computed by integrating Maxwell and Cauchy stress tensors to determine whether the particles are pushed toward or away from the electrode gap at frequencies of 10 Hz...

Drummond, Franklin Jerrel

2011-10-21T23:59:59.000Z

488

FEHM (Finite Element Heat and Mass Transfer Code)  

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 Enhancedenvironmental stewardshipDevelopmentFEHM

489

The Uranium Processing Facility (UPF) Finite Element Meshing Discussion |  

Office of Environmental Management (EM)

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 May Jun Jul(Summary) "of Energy Power.pdf11-161-LNGInternationalTechnology ValidationMilestoneDepartmentDepartment of Energy

490

The Uranium Processing Facility Finite Element Meshing Discussion  

Office of Environmental Management (EM)

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 May Jun Jul(Summary) "of EnergyEnergyENERGYWomen Owned SmallOf The 2012 Greenbuy Program. | DepartmentManagementLasSavings for1

491

Sandia National Laboratories: Abaqus finite-element analysis software  

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 MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 ResourceAwardsSafeguardsEngineers WindARPA-E ARPAe:ASMEATP3

492

The Finite Element Analusis of Ventilative Motorcycle Helmets.  

E-Print Network [OSTI]

??In Taiwan, a motorcycle is the most important and general transportation. It is no denying that wearing a motorcycle helmet could prevent the rider from (more)

Shen, Jhuo-ying

2008-01-01T23:59:59.000Z

493

Xu Zhang's Homepage - Research  

E-Print Network [OSTI]

Research Interests. Numerical Methods for Partial Differential Equations; Finite Element and Discontinuous Galerkin Methods; Immersed Finite Element Methods

494

Quantum Mechanics associated with a Finite Group  

E-Print Network [OSTI]

I describe, in the simplified context of finite groups and their representations, a mathematical model for a physical system that contains both its quantum and classical aspects. The physically observable system is associated with the space containing elements fxf for f an element in the regular representation of a given finite group G. The Hermitian portion of fxf is the Wigner distribution of f whose convolution with a test function leads to a mathematical description of the quantum measurement process. Starting with the Jacobi group that is formed from the semidirect product of the Heisenberg group with its automorphism group SL(2,F{N}) for N an odd prime number I show that the classical phase space is the first order term in a series of subspaces of the Hermitian portion of fxf that are stable under SL(2,F{N}). I define a derivative that is analogous to a pseudodifferential operator to enable a treatment that parallels the continuum case. I give a new derivation of the Schrodinger-Weil representation of the Jacobi group. Keywords: quantum mechanics, finite group, metaplectic. PACS: 03.65.Fd; 02.10.De; 03.65.Ta.

Robert W. Johnson

2006-04-20T23:59:59.000Z

495

Shape and pairing fluctuations effects on neutrinoless double beta decay nuclear matrix elements  

E-Print Network [OSTI]

Nuclear matrix elements (NME) for the most promising candidates to detect neutrinoless double beta decay have been computed with energy density functional methods including deformation and pairing fluctuations explicitly on the same footing. The method preserves particle number and angular momentum symmetries and can be applied to any decay without additional fine tunings. The finite range density dependent Gogny force is used in the calculations. An increase of $10\\%-40\\%$ in the NME with respect to the ones found without the inclusion of pairing fluctuations is obtained, reducing the predicted half-lives of these isotopes.

Nuria Lpez Vaquero; Toms R. Rodrguez; J. Luis Egido

2014-01-03T23:59:59.000Z

496

FINITE DISJUNCTIVE PROGRAMMING CHARACTERIZATIONS ...  

E-Print Network [OSTI]

In this paper, we give a finite disjunctive programming procedure to obtain .... In this paper, assuming a nonempty feasible set and bounded general integer variables ..... to find the last node ? on the path from the root node such that xk ? C?. There are two ..... http://arxiv.org/PS cache/arxiv/pdf/0707/0707.3945v1.pdf.

2010-03-07T23:59:59.000Z

497

Apparatus for and method of simulating turbulence  

DOE Patents [OSTI]

In accordance with a preferred embodiment of the invention, a novel apparatus for and method of simulating physical processes such as fluid flow is provided. Fluid flow near a boundary or wall of an object is represented by a collection of vortex sheet layers. The layers are composed of a grid or mesh of one or more geometrically shaped space filling elements. In the preferred embodiment, the space filling elements take on a triangular shape. An Eulerian approach is employed for the vortex sheets, where a finite-volume scheme is used on the prismatic grid formed by the vortex sheet layers. A Lagrangian approach is employed for the vortical elements (e.g., vortex tubes or filaments) found in the remainder of the flow domain. To reduce the computational time, a hairpin removal scheme is employed to reduce the number of vortex filaments, and a Fast Multipole Method (FMM), preferably implemented using parallel processing techniques, reduces the computation of the velocity field.

Dimas, Athanassios (Rockville, MD); Lottati, Isaac (Potomac, MD); Bernard, Peter (Silver Spring, MD); Collins, James (Sykesville, MD); Geiger, James C. (Rockville, MD)

2003-01-01T23:59:59.000Z

498

Finite generation conjectures for cohomology over finite fields.  

E-Print Network [OSTI]

We construct an intermediate cohmology between motivic cohomology and Weil-etale cohomology. Using this, the Bass conjecture on finite generation of motivic cohomology, and the Beilinson-Tate on the finite generation of Weil-etale cohomology are related.

Thomas H Geisser

499

Finite volume renormalization scheme for fermionic operators  

SciTech Connect (OSTI)

We propose a new finite volume renormalization scheme. Our scheme is based on the Gradient Flow applied to both fermion and gauge fields and, much like the Schr\\"odinger functional method, allows for a nonperturbative determination of the scale dependence of operators using a step-scaling approach. We give some preliminary results for the pseudo-scalar density in the quenched approximation.

Monahan, Christopher; Orginos, Kostas [JLAB

2013-11-01T23:59:59.000Z

500

Applying one-dimensional fluid thermal elements into a 3D CLIC accelerating strucutre  

E-Print Network [OSTI]

A finite element modeling method to simplify the analysis of coupled thermal-structural model for the CLIC accelerating structure is presented. In addition, the results of thermal and structural analyses for the accelerating structure are presented. Instead of using a standard 3D computational fluid dynamics (CFD) method for solving problems involving fluid dynamics and heat transfer in 3D environment, one-dimensional fluid thermal elements are used. In one-dimensional flow, the governing equations of fluid dynamics are considerably simplified. Thus, it is expected that the computational time for more complex simulations becomes shorter. The method was first applied to several test models, which demonstrated the suitability of the one-dimensional flow modeling. The results show that one-dimensional fluid flow reduces the computation time considerably allowing the modeling for the future larger assemblies with sufficient accuracy.

Raatikainen, Riku; sterberg, Kenneth; Riddone, Germana; Samoshkin, Alexander; Gudkov, Dmitry

2010-01-01T23:59:59.000Z