ME 872 -Finite Element Methods Spring 2014
Diaz, Alejandro
Element Method: Linear Static and Dynamic Finite Element Analysis (Dover Civil and Mechanical Engineering problems Special topics: Lagrange multipliers, adaptive finite elements, sensitivity analysis, nonlinearME 872 - Finite Element Methods Spring 2014 Catalog Description: Theory and application
2003-12-06
a volume integral formulation of the problem with a finite partitioning set of ... where ?0 and ?1 partition the boundary of ?, the ds-measure of ?0 is strictly positive ...
Combined Finite Element --Finite Volume Method ( Convergence Analysis )
Magdeburg, Universität
Combined Finite Element -- Finite Volume Method ( Convergence Analysis ) M'aria Luk idea is to combine finite volume and finite element methods in an appropriate way. Thus nonlinear grid. Diffusion terms are discretized by the conforming piecewise linear finite element method
Generalized finite element method for Helmholtz equation
Hidajat, Realino Lulie
2009-05-15
This dissertation presents the Generalized Finite Element Method (GFEM) for the scalar Helmholtz equation, which describes the time harmonic acoustic wave propagation problem. We introduce several handbook functions for ...
PARTIALLY PENALIZED IMMERSED FINITE ELEMENT METHODS ...
2015-01-05
This article presents new immersed finite element (IFE) methods for solving the ... convergence rate in an energy norm provided that the exact solution has ... An alternative approach is ...... North-Holland Publishing Co., Amsterdam-New York-.
Programing the Finite Element Method with Matlab
2002-10-03
Oct 3, 2002 ... in the writing of finite element code using Matlab. It is assumed .... Ultimately for all finite element programs we solve a linear algebraic system of the form .... equations is the enforcement of the essential boundary conditions.
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE ...
2015-06-30
Scattering theory in periodic structures, which is crucial in application .... is used to design the adaptive finite element algorithm to choose elements for refine-.
Discontinuous finite element methods for particle transport problems
Stone, Hiromi
2002-01-01
We develop, analyze, and test a new discontinuous finite element method (DFEM), namely the piece-wise linear discontinuous (PWLD) method for transport problems. We compare the PWLD method against the rational finite element (RFE) method. We show...
Math/AMath 595: Finite Element Methods (Winter 2001)
Stein, William
for Elliptic Problems by Philippe G. Ciarlet (1978). 3. An Analysis of the Finite Element Method by GilbertMath/AMath 595: Finite Element Methods (Winter 2001) Lectures: MW 3:30{4:50, room 121 RAI Professor Element Methods by Susanne C. Brenner and L. Ridgway Scott (1994). 2. The Finite Element Method
ANALYSIS OF SOME MOVING SPACETIME FINITE ELEMENT METHODS \\Lambda
Bank, Randolph E.
ANALYSIS OF SOME MOVING SPACETIME FINITE ELEMENT METHODS \\Lambda RANDOLPH E. BANK y AND RAFAEL F. SANTOS z Abstract. Two spacetime finite element methods for solving timedependent partial differential equations are defined and analyzed. The methods are based on the use of isoparametric finite elements
AN ADAPTIVE SURFACE FINITE ELEMENT METHOD BASED ON VOLUME MESHES
Demlow, Alan
studied in this paper. The paper of Dziuk [12] contains the first analysis of a finite element methodAN ADAPTIVE SURFACE FINITE ELEMENT METHOD BASED ON VOLUME MESHES ALAN DEMLOW AND MAXIM A. OLSHANSKII Abstract. In this paper we define an adaptive version of a recently introduced finite element
A finite element method and the method of finite spheres enriched for analysis of wave propagations
Ham, Seounghyun, 1982-
2014-01-01
The objective of this thesis is to present a finite element method and the method of finite spheres enriched for the solution of various wave propagation problems. The first part of this thesis is to present an enriched ...
Analysis of a Combined Barycentric Finite Volume --Nonconforming Finite Element Method for Nonlinear
Dolejsi, Vit
Analysis of a Combined Barycentric Finite Volume -- Nonconforming Finite Element Method, the theoretical analysis of the combined finite volume -- finite element method has been carried out for the case term is discretized by piecewise linear nonconforming triangular finite elements. Under the assumption
Complex Wavenumber Fourier Analysis of the PVersion Finite Element Method
Thompson, Lonny L.
Complex Wavenumber Fourier Analysis of the PVersion Finite Element Method Lonny L. Thompson wave solutions. This type of analysis amounts to a discrete Fourier synthesis of the finite element bands in the context of finite element analysis were not fully understood, although there is some
Adaptive finite element method for eddy current problems
Adaptive finite element method for eddy current problems. In this chapter we shall discuss Maxwell's equations at very low frequencies. We also refer to [bo98 ...
ADAPTIVE FINITE ELEMENT FREQUENCY DOMAIN METHOD FOR EDDY CURRENT PROBLEMS
Zheng, Weiying
ADAPTIVE FINITE ELEMENT FREQUENCY DOMAIN METHOD FOR EDDY CURRENT PROBLEMS WEIYING ZHENG-harmonic eddy current problems in the case of three-dimensional isotropic and linear materials. We adopt. Time-harmonic Maxwell's equations, eddy current, adaptive finite element method, multiply connected
A Note on the Finite Element Method with Singular Basis Functions
Kaneko, Hideaki
finite element analysis that incorporates singular element functions. A need for introducing * *some singular elements as part of basis functions in certain finite element analysis arises o* *ut A Note on the Finite Element Method with Singular Basis
An application of stochastic finite element method in structural reliabiity
Agrawal, Sanjay
1993-01-01
AN APPLICATION OF STOCHASTIC FINITE ELEMENT METHOD IN STRUCTURAL RELIABILITY A Thesis by SAN JAY AGRAWAL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE 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...
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE WAVE ...
2015-09-09
Consider the acoustic wave scattering by an impenetrable obstacle in two dimensions. ... adaptive finite element algorithm is proposed for solving the acoustic ... element methods [19,20] and the boundary integral equation methods [11]. ...... rem 4.1, we use the PDE toolbox of MATLAB to implement the adaptive algorithm of.
A LOCAL PROJECTION STABILIZATION FINITE ELEMENT METHOD WITH NONLINEAR CROSSWIND DIFFUSION FOR
John, Volker
A LOCAL PROJECTION STABILIZATION FINITE ELEMENT METHOD WITH NONLINEAR CROSSWIND DIFFUSION and phrases. finite element method; local projection stabilization; crosswind diffusion; convection
Coupled finite element and meshfree method Application to wide-flange steel sections
Yaw, Louis L.
, 2007 Yaw, Kunnath & Sukumar Meshfree Inelastic Frame Analysis #12;Motivation Coupled finite element Inelastic Frame Analysis #12;Motivation Coupled finite element and meshfree method Application to wide & Sukumar Meshfree Inelastic Frame Analysis #12;Motivation Coupled finite element and meshfree method
Control-volume mixed finite element methods
1998-01-23
As techniques of reservoir description become more sophisticated, .... [12] have applied these methods to petroleum reservoir ...... a concern in principle because the curvilinear faces, normal vectors, and fluxes are ..... Proceedings of the 11th SPE Symposium on Reservoir Simulation (Society of Petroleum Engineers,.
STRUCTURAL TOPOLOGY OPTIMIZATION USING FINITE ELEMENT BASED LEVEL SET METHOD
Frey, Pascal
of Mechanical and Automation Engineering The Chinese University of Hong Kong THEME Optimization KEYWORDS, the standard Galerkin finite element method may produce oscillating results. In this paper, both equations set equation is a first order hyperbolic equation. It is well known that the standard Galerkin FEM may
Course Announcement: Spring 2015 Finite Element Methods for Engineers
.v.griffiths@mines.edu Web: www.mines.edu/~vgriffit This course combines finite element theory with practical programming
FINITE ELEMENT METHOD IN FLUID MECHANICS & HEAT TRANSFER
Camci, Cengiz
completed this course should be able to perform quick analysis of small problems using the finite element of Fluid Mechanics and Heat Transfer An Introduction to Finite Element Analysis Using "Galerkin Weak of Euler's Equation in Finite Element Analysis Generalized Form of Euler's Equation in Three Dimensional
Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach
Frisani, Angelo 1980-
2012-12-07
immersed boundary methods are in good agreement with the predictions from STAR-CCM+ and the numerical data from the other IBMs. The immersed boundary method based of finite element approach is numerically more accurate than the IBM based on finite volume...
THE BUBBLE TRANSFORM: A NEW TOOL FOR ANALYSIS OF FINITE ELEMENT METHODS
THE BUBBLE TRANSFORM: A NEW TOOL FOR ANALYSIS OF FINITE ELEMENT METHODS RICHARD S. FALK AND RAGNAR estimates for various finite element methods. In particular, for the analysis of mixed finite element be very useful, but hard to construct, is the analysis of the so-called p-version of the finite element
An efficient finite element method applied to quantum billiard systems
Woo-Sik Son; Sunghwan Rim; Chil-Min Kim
2009-02-25
An efficient finite element method (FEM) for calculating eigenvalues and eigenfunctions of quantum billiard systems is presented. We consider the FEM based on triangular $C_1$ continuity quartic interpolation. Various shapes of quantum billiards including an integrable unit circle are treated. The numerical results show that the applied method provides accurate set of eigenvalues exceeding a thousand levels for any shape of quantum billiards on a personal computer. Comparison with the results from the FEM based on well-known $C_0$ continuity quadratic interpolation proves the efficiency of the method.
Adaptive Finite Element Method for Time-domain Maxwell's ...
Shuhao Cao supervised under Professor Cai
2013-10-31
Oct 11, 2013 ... Avoiding the pollution of the finite element approximation, a.k.a. the spurious modes. Lowest-order element's DoFs associated with edges, and.
THE STEFAN PROBLEM: A STOCHASTIC ANALYSIS USING THE EXTENDED FINITE ELEMENT METHOD
Zabaras, Nicholas J.
THE STEFAN PROBLEM: A STOCHASTIC ANALYSIS USING THE EXTENDED FINITE ELEMENT METHOD Baskar these uncertainties in a stochastic sense using the extended finite element method as the deterministic solution convection using the extended finite element method (XFEM) and level set methods," Journal of Computational
ANALYSIS OF A FINITE VOLUME ELEMENT METHOD FOR THE STOKES PROBLEM
Paris-Sud XI, Université de
ANALYSIS OF A FINITE VOLUME ELEMENT METHOD FOR THE STOKES PROBLEM ALFIO QUARTERONI, AND RICARDO stabilization, finite volume element method, a priori error estimates, superconvergence analysis. CMCS RUIZ BAIER Abstract. In this paper we propose a stabilized conforming finite volume element method
Xia, Yi-Ming
2015-01-01
A locking-free rectangular Mindlin plate element with a new multi-resolution analysis (MRA) is proposed and a multireolution finite element method is hence presented. The MRA framework is formulated out of a mutually nesting displacement subspace sequence. The MRA endows the proposed element with the resolution level (RL) to adjust the element node number, thus modulating structural analysis accuracy accordingly. As a result, the traditional 4-node rectangular Mindlin plate element and method is a mono-resolution one and also a special case of the proposed element and method. The meshing for the monoresolution plate element model is based on the empiricism while the RL adjusting for the multiresolution is laid on the rigorous mathematical basis. The accuracy of a structural analysis is actually determined by the RL, not by the mesh. The rational MRA enables the implementation of the multiresolution Mindlin plate element method to be more rational and efficient than that of the conventional monoresolution or o...
Analysis of Conforming and Nonconforming Quadrilateral Finite Element Methods for the
Sheen, Dongwoo
Analysis of Conforming and Nonconforming Quadrilateral Finite Element Methods for the Helmholtz in this analysis are the standard Q1 conforming finite element, the DSSY nonconforming element [5] and the P1-Santos-Sheen-Bennethum in [4]; also in the same paper a first rigorous finite element error analysis was carried out
ME 538: Introduction to Finite Element Methods and Analysis Instructor and Class Information
Lin, Xi
ME 538: Introduction to Finite Element Methods and Analysis Fall 2014 Instructor and Class edition, Thomson 2012 Reference Books · Concepts and applications of finite element analysis by R.D. Cook@gmail.com) Course Summary This class serves as an introduction to the linear finite element method, and its
Finite size scaling for quantum criticality using the finite-element method
Edwin Antillon; Birgit Wehefritz-Kaufmann; Sabre Kais
2012-03-08
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.
A PIECEWISE LINEAR FINITE ELEMENT METHOD FOR THE BUCKLING AND THE VIBRATION PROBLEMS OF THIN
Rodríguez, Rodolfo
A PIECEWISE LINEAR FINITE ELEMENT METHOD FOR THE BUCKLING AND THE VIBRATION PROBLEMS OF THIN PLATES finite element method to approximate the buckling and the vibration problems of a thin plate. The method]). The method was applied to the plate vibration problem in [6] and [17, Section 7(b)], where it was proved
Paris-Sud XI, Université de
Analysis of the finite element heterogeneous multiscale method for nonlinear elliptic homogenization problems. Assyr Abdulle and Gilles Vilmart September 28, 2012 Abstract An analysis of the finite finite elements. Op- timal a-priori error estimates are obtained for the H1 and L2 norms, error bounds
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE H -FORMULATION OF TIME-DEPENDENT EDDY CURRENT
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE H - FORMULATION OF TIME-DEPENDENT EDDY CURRENT PROBLEMS, eddy current problem, adaptive finite element method, mul- tiply connected conductor, Team Workshop Problem 7 AMS subject classifications. 65M60, 65M50, 78A25 1. Introduction. Eddy currents appear in almost
Bangerth, Wolfgang
Adaptive finite element methods for forward modeling in fluorescence enhanced frequency domain for Subsurface Modeling, ICES, University of Texas, Austin, TX Abstract: An adaptive finite element scheme the boundary measurements of photon energy resulting from the tissue stimulation via infrared light sources
LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS
RodrÃguez, Rodolfo
LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS FELIPE LEPE, DAVID MORA, AND RODOLFO RODRÂ´IGUEZ Abstract. In this paper we study a finite element formulation of the transverse displacement, rota- tion, shear stress and bending moment. By using the classical Babuska
Unconstrained paving and plastering method for generating finite element meshes
Staten, Matthew L. (Albuquerque, NM); Owen, Steven J. (Albuquerque, NM); Blacker, Teddy D. (Albuquerque, NM); Kerr, Robert (Albuquerque, NM)
2010-03-02
Computer software for and a method of generating a conformal all quadrilateral or hexahedral mesh comprising selecting an object with unmeshed boundaries and performing the following while unmeshed voids are larger than twice a desired element size and unrecognizable as either a midpoint subdividable or pave-and-sweepable polyhedra: selecting a front to advance; based on sizes of fronts and angles with adjacent fronts, determining which adjacent fronts should be advanced with the selected front; advancing the fronts; detecting proximities with other nearby fronts; resolving any found proximities; forming quadrilaterals or unconstrained columns of hexahedra where two layers cross; and establishing hexahedral elements where three layers cross.
A Method for Connecting Dissimilar Finite Element Meshes in Three Dimensions
Dohrmann, C.R.; Heinstein, M.W.; Key, S.W.
1998-11-12
A method is presented for connecting dissimilar finite element meshes in three dimensions. The method combines the concept of master and slave surfaces with the uniform strain approach for surface, corrections finite elements- By modifyhg the are made to element formulations boundaries of elements on the slave such that first-order patch tests are passed. The method can be used to connect meshes which use different element types. In addition, master and slave surfaces can be designated independently of relative mesh resolutions. Example problems in three-dimensional linear elasticity are presented.
Higher Order Discontinuous Finite Element Methods for Discrete Ordinates Thermal Radiative Transfer
Maginot, Peter G
2015-07-28
The linear discontinuous finite element method (LDFEM) is the current work horse of the radiation transport community. The popularity of LDFEM is a result of LDFEM (and its Q1 multi-dimensional extensions) being both ...
Harrison, Mark
1988-01-01
IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full are given and then a discrete-time, explicit finite element procedure is defined and analysed, with finite on the existence, uniqueness and finite element approximation of the solution of Biot's equations were given in [15
Rumpf, Martin
16th Workshop on the Finite Element Method in Biomedical Engineering, Biomechanics and Related. This is a convenient approach in practice because frequently in biomechanics geometric interfaces are described via 3D
Suo, Zhigang
A dynamic finite element method for inhomogeneous deformation and electromechanical instability Electromechanical instability Wrinkling Snap through a b s t r a c t We present a three-dimensional nonlinear finite the basis for needed computational tools that can elucidate the electromechanical behavior and properties
A Finite Element Method Using Singular Functions: Interface Problems
2008-03-06
The solution of the interface problem is only in H1+?(?) with ? > 0 possibly close to zero ...... To this end, let Th be a partition of the domain ? into triangular finite.
Partially Penalized Immersed Finite Element Methods for Parabolic ...
2015-01-26
to parabolic interface problem together with the Laplacian transform. Parabolic .... We then partition K into two sub-elements K? and K+ by the line segment ...
Numerical Analysis of a Mixed Finite Element Method for a FlowTransport Problem
Chou, So-Hsiang
a waste disposal problem in which high level radioactive waste is buried in a salt dome, the salt dissolves to create a brine, radioactive elements decay to generate heat, and radionuclides are transportedNumerical Analysis of a Mixed Finite Element Method for a FlowTransport Problem S. H. CHOU AND Q
Zornberg, Jorge G.
1391 1 INTRODUCTION An application of the finite element method (FEM) for non-linear elastoplastic, 2003; Oliveira, 2006). 2 FINITE ELEMENT REPRESENTATION OF REINFORCED SOIL A discrete representation, the reinforcement and the soil-reinforcement interface-- can be represented using a specific finite element with its
ADAPTIVE DISCONTINUOUS GALERKIN FINITE ELEMENT METHODS FOR NONLINEAR HYPERBOLIC CONSERVATION
Hartmann, Ralf
RALF HARTMANN #3; AND PAUL HOUSTON y Abstract. We consider the a posteriori error analysis and adaptive, University of Heidelberg, Im Neuenheimer Feld 293, D-69120 Heidelberg, Germany (e-mail: Ralf.Hartmann-mail: Paul.Houston@mcs.le.ac.uk). 1 #12; 2 R. HARTMANN and P. HOUSTON estimates, the element residuals
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE EDDY CURRENT MODEL WITH CIRCUIT/FIELD COUPLINGS
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE EDDY CURRENT MODEL WITH CIRCUIT/FIELD COUPLINGS JUNQING for solving the eddy current model with voltage excitations for complicated three dimensional structures of the proposed method. Key words. Eddy current, circuit/field coupling, adaptivity, a posteriori error analysis
STABILIZED FINITE ELEMENT METHODS FOR FLOWS WITH MOVING BOUNDARIES AND INTERFACES
Tezduyar, Tayfun E.
1 STABILIZED FINITE ELEMENT METHODS FOR FLOWS WITH MOVING BOUNDARIES AND INTERFACES Tayfun E boundaries and interfaces. The methods developed can be classified into two main categories: interface-tracking and interface-capturing techniques. Both classes of techniques are based on sta- bilized formulations
STABILIZED FINITE ELEMENT METHODS FOR COMPUTATION OF FLOWS WITH MOVING BOUNDARIES AND INTERFACES
Tezduyar, Tayfun E.
1 STABILIZED FINITE ELEMENT METHODS FOR COMPUTATION OF FLOWS WITH MOVING BOUNDARIES AND INTERFACES of flow problems with moving boundaries and interfaces. The methods developed are categorized into two classes: interface-tracking and interface-capturing techniques. Both classes of techniques are based
A Finite Element Method for Fully Nonlinear and General Quasilinear Elliptic Problems
Pryer, Tristan
2011-01-01
We present a continuous finite element method for fully nonlinear elliptic equations. The tools we use are (1) a Newton linearisation, yielding a sequence of linear PDEs in nonvariational form and (2) the discretisation proposed in [LP11] allowing us to work directly on the strong form of a linear PDE. An added benefit to making use of this discretisation method is that a recovered (finite element) Hessian is a biproduct of the solution process. Benchmark numerical results illustrate the convergence properties of the scheme for some test problems.
Gradient recovery in adaptive finite element methods for parabolic problems
Lakkis, Omar
2009-01-01
We derive energy-norm aposteriori error bounds, using gradient recovery (ZZ) estimators to control the spatial error, for fully discrete schemes for the linear heat equation. This appears to be the first completely rigorous derivation of ZZ estimators for fully discrete schemes for evolution problems, without any restrictive assumption on the timestep size. An essential tool for the analysis is the elliptic reconstruction technique. Our theoretical results are backed with extensive numerical experimentation aimed at (a) testing the practical sharpness and asymptotic behaviour of the error estimator against the error, and (b) deriving an adaptive method based on our estimators. An extra novelty provided is an implementation of a coarsening error "preindicator", with a complete implementation guide in ALBERTA.
Wells, G N
2009-10-28
This solver is in support of the paper 'Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation', by Garth N. Wells...
AN hp FINITE ELEMENT METHOD TO SOLVE A FLUID-SOLID VIBRATION PROBLEM
Rodríguez, Rodolfo
AN hp FINITE ELEMENT METHOD TO SOLVE A FLUID-SOLID VIBRATION PROBLEM CLAUDIO PADRA, RODOLFO RODR´IGUEZ , AND MARIO SCHEBLE § Abstract. This paper deals with a two-dimensional fluid-solid vibration problem arising from nuclear engineering: the vibration of elastically mounted tubes immersed in a cavity filled
Finite Element Method for Epitaxial Growth with Attachment-Detachment Kinetics
Li, Bo
growth of thin films. Epitaxial growth is a technology for growing single crystal thin filmsFinite Element Method for Epitaxial Growth with Attachment-Detachment Kinetics Eberhard B in epitaxial growth. Such problems consist of an adatom (adsorbed atom) diffusion equation on terraces
Modeling Respiratory Lung Motion a Biophysical Approach using Finite Element Methods
Lübeck, Universität zu
Modeling Respiratory Lung Motion a Biophysical Approach using Finite Element Methods Rene Wernera motion gains in importance. In this paper a biophysical approach for modeling lung motion is described. Main aspects of the process of lung ventilation are identified and outlined as the starting point
Bangerth, Wolfgang
error estimates for adaptive mesh refinement to optimally model the strongly graded light distributionADAPTIVE FINITE ELEMENT METHODS FOR FLUORESCENCE ENHANCED FREQUENCY DOMAIN OPTICAL TOMOGRAPHY Modeling, ICES, University of Texas at Austin, TX ABSTRACT In this contribution we introduce adaptive
Advanced finite-element methods for design and analysis of nanooptical structures: Applications
Burger, S; Pomplun, J; Blome, M; Schmidt, F; 10.1117/12.2001094
2013-01-01
An overview on recent applications of the finite-element method Maxwell-solver JCMsuite to simulation tasks in nanooptics is given. Numerical achievements in the fields of optical metamaterials, plasmonics, photonic crystal fibers, light emitting devices, solar cells, optical lithography, optical metrology, integrated optics, and photonic crystals are summarized.
Elgeti, Stefanie
2015-01-01
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 ...
Recanati, Catherine
A finite element method with mesh adaptivity for computing vortex states in fastrotating BoseEinstein Abstract Numerical computations of stationary states of fastrotating BoseEinstein condensates require rotation rates). Key words: Gross--Pitaevskii equation, finite element method, mesh adaptivity, BoseEinstein
Swaddiwudhipong, S; Liu, Z S
2012-01-01
Finite element method (FEM) suffers from a serious mesh distortion problem when used for high velocity impact analyses. The smooth particle hydrodynamics (SPH) method is appropriate for this class of problems involving severe damages but at considerable computational cost. It is beneficial if the latter is adopted only in severely distorted regions and FEM further away. The coupled smooth particle hydrodynamics - finite element method (SFM) has been adopted in a commercial hydrocode LS-DYNA to study the perforation of Weldox 460E steel and AA5083-H116 aluminum plates with varying thicknesses and various projectile nose geometries including blunt, conical and ogival noses. Effects of the SPH domain size and particle density are studied considering the friction effect between the projectile and the target materials. The simulated residual velocities and the ballistic limit velocities from the SFM agree well with the published experimental data. The study shows that SFM is able to emulate the same failure mechan...
Mixed-RKDG Finite Element Methods for the 2-D Hydrodynamic Model for Semiconductor Device Simulation
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chen, Zhangxin; Cockburn, Bernardo; Jerome, Joseph W.; Shu, Chi-Wang
1995-01-01
In this paper we introduce a new method for numerically solving the equations of the hydrodynamic model for semiconductor devices in two space dimensions. The method combines a standard mixed finite element method, used to obtain directly an approximation to the electric field, with the so-called Runge-Kutta Discontinuous Galerkin (RKDG) method, originally devised for numerically solving multi-dimensional hyperbolic systems of conservation laws, which is applied here to the convective part of the equations. Numerical simulations showing the performance of the new method are displayed, and the results compared with those obtained by using Essentially Nonoscillatory (ENO) finite difference schemes. Frommore »the perspective of device modeling, these methods are robust, since they are capable of encompassing broad parameter ranges, including those for which shock formation is possible. The simulations presented here are for Gallium Arsenide at room temperature, but we have tested them much more generally with considerable success.« less
Permeability computation on a REV with an immersed finite element method
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)
2011-05-04
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.
Gao, Kai; Gibson, Richard L; Chung, Eric T; Efendiev, Yalchin
2014-01-01
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both boundaries and the interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and di...
An h-adaptive finite element method for turbulent heat transfer
Carriington, David B [Los Alamos National Laboratory
2009-01-01
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.
A topology-motivated mixed finite element method for dynamic response of porous media
Lotfian, Zahrasadat
2015-01-01
In this paper, we propose a numerical method for computing solutions to Biot's fully dynamic model of incompressible saturated porous media [Biot;1956]. Our spatial discretization scheme is based on the three-field formulation (u-w-p) and the coupling of a lowest order Raviart-Thomas mixed element [Raviart,Thomas;1977] for fluid variable fields (w, p ) and a nodal Galerkin finite element for skeleton variable field (u). These mixed spaces are constructed based on the natural topology of the variables; hence, are physically compatible and able to exactly model the kind of continuity which is expected. The method automatically satisfies the well known LBB (inf-sup) stability condition and avoids locking that usually occurs in the numerical computations in the incompressible limit and very low hydraulic conductivity. In contrast to the majority of approaches, our three-field formulation can fully capture dynamic behavior of porous media even in high frequency loading phenomena with considerable fluid acceleratio...
Pontaza, Juan Pablo
2004-09-30
We consider the application of least-squares variational principles and the finite element method to the numerical solution of boundary value problems arising in the fields of solidand fluidmechanics.For manyof these ...
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)
2014-02-18
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.
Higher-order adaptive finite-element methods for Kohn–Sham density functional theory
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)
2013-11-15
We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn–Sham 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 Gauss–Lobatto quadrature, and a Chebyshev acceleration technique for computing the occupied eigenspace. The proposed approach has been observed to provide a staggering 100–200-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 Kohn–Sham DFT problem. Our studies suggest that staggering computational savings—of the order of 1000-fold—relative 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 Kohn–Sham 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.
Medial Techniques for Automating Finite Element Analysis
Whitton, Mary C.
Medial Techniques for Automating Finite Element Analysis by Jessica Renee Crawford Crouch Analysis. (Under the direction of Stephen M. Pizer.) Finite element analysis provides a principled method the simulation of tissue deformation. The drawback to using finite element analysis for imaging problems
Finite Element Analysis in Vertebrate Biomechanics
Finite Element Analysis in Vertebrate Biomechanics CALLUM F. ROSS* Department of Organismal Biology presents a series of papers that apply the method of finite element analysis (FEA) to questions ontogenetic or phylogenetic transformations. © 2005 Wiley-Liss, Inc. Key words: finite-element analysis
Liu, Xuchen
2015-05-04
surrounded by soft tissues, 2) a layered ring model representing an arterial wall cross-section. The hypothetical "measured" displacement field for these problem domains will be created by solving the finite element forward problem. Additionally, noise...
Chen, Lingfeng, M. Eng. Massachusetts Institute of Technology
2014-01-01
Common finite element programs for plate bending analysis are complicated and limited by the common plate theories. Such programs are usually not user-friendly for designers to implement. Lately, Hou Man et al. from the ...
Probabilistic finite element analysis of a craniofacial finite element model Michael A. Berthaume a s t r a c t We employed a probabilistic finite element analysis (FEA) method to determine how 2011 Accepted 18 January 2012 Available online 27 January 2012 Keywords: Probabilistic analysis Finite
Modeling a bender element test using Abaqus Finite Element Program
Johnson, Sean (Sean Michael)
2011-01-01
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 ...
A Generalized Multiscale Finite Element Method for Poroelasticity Problems I: Linear Problems
Brown, Donald L
2015-01-01
In this paper, we consider the numerical solution of poroelasticity problems that are of Biot type and develop a general algorithm for solving coupled systems. We discuss the challenges associated with mechanics and flow problems in heterogeneous media. The two primary issues being the multiscale nature of the media and the solutions of the fluid and mechanics variables traditionally developed with separate grids and methods. For the numerical solution we develop and implement a Generalized Multiscale Finite Element Method (GMsFEM) that solves problem on a coarse grid by constructing local multiscale basis functions. The procedure begins with construction of multiscale bases for both displacement and pressure in each coarse block. Using a snapshot space and local spectral problems, we construct a basis of reduced dimension. Finally, after multiplying by a multiscale partitions of unity, the multiscale basis is constructed in the offline phase and the coarse grid problem then can be solved for arbitrary forcin...
Comparison of methods for solving nonlinear finite-element equations in heat transfer
Cort, G.E.; Graham, A.L.; Johnson, N.L.
1981-01-01
We have derived two new techniques for solving the finite-element heat-transfer equations with highly nonlinear boundary conditions and material properties. When compared with the more commonly employed successive substitution and Newton-Raphson procedures, the new methods speed convergence rates and simultaneously increase the radius of convergence. We have observed reductions in computation time in excess of 80% when the new techniques are employed. The first method accelerates the standard Newton-Raphson approach when the degree of the nonlinearity is known (for example, radiation boundary conditions or a prescribed temperature dependence in the thermal conductivity). The second technique employs feedback to regulate the solution algorithm during execution. Comparisons of these techniques are given for several practical examples.
Finite Element Analysis Skateboard Truck
De, Suvranu
Finite Element Analysis Of a Skateboard Truck #12;2 Executive Summary: Engineering is and always is an element of the `truck,' which holds the wheels. Finite Element analysis will be conducted on this piece a combination of SolidWorks (for modeling) and ABAQUS (for finite element analysis). It is evident from
Local Jacobi Operators and Applications to the p-version of Finite Element Method in Two Dimensions
Guo, Benqi
Local Jacobi Operators and Applications to the p-version of Finite Element Method in Two Dimensions Benqi Guo Ivo Babuska Abstract Based on Jacobi projection operators p, on elements and edges we have designed local Jacobi operators j for smooth and singular solution on each triangular and quadrilateral
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gao, Kai; Fu, Shubin; Gibson, Richard L.; Chung, Eric T.; Efendiev, Yalchin
2015-04-14
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale mediummore »property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.« less
ECI 212A: Finite Element Procedures in Applied Mechanics
Schladow, S. Geoffrey
), "The Finite Element Method: Linear Static and Dynamic Finite Element Analysis," Prentice), "Concepts and Appli- cations of Finite Element Analysis," 4th Ed., John Wiley and Sons, NY. 5. M. S, Philadelphia, PA. 6. G. Strang and G. J. Fix (1973), "An Analysis of the Finite Element Method," Prentice
Tezduyar, Tayfun E.
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
Firoozabadi, Abbas
approach to mitigate global warming. Several unique phase behavior properties make CO2 especially reservoirs, and the solubility in both light and heavy oil may be very high. [3] Upon dissolution, CO2 mayThree-phase compositional modeling of CO2 injection by higher-order finite element methods with CPA
Full wave simulation of waves in ECRIS plasmas based on the finite element method
Torrisi, G.; Mascali, D.; Neri, L.; Castro, G.; Patti, G.; Celona, L.; Gammino, S.; Ciavola, G.; Di Donato, L.; Sorbello, G.; Isernia, T.
2014-02-12
This paper describes the modeling and the full wave numerical simulation of electromagnetic waves propagation and absorption in an anisotropic magnetized plasma filling the resonant cavity of an electron cyclotron resonance ion source (ECRIS). The model assumes inhomogeneous, dispersive and tensorial constitutive relations. Maxwell's equations are solved by the finite element method (FEM), using the COMSOL Multiphysics{sup ®} suite. All the relevant details have been considered in the model, including the non uniform external magnetostatic field used for plasma confinement, the local electron density profile resulting in the full-3D non uniform magnetized plasma complex dielectric tensor. The more accurate plasma simulations clearly show the importance of cavity effect on wave propagation and the effects of a resonant surface. These studies are the pillars for an improved ECRIS plasma modeling, that is mandatory to optimize the ion source output (beam intensity distribution and charge state, especially). Any new project concerning the advanced ECRIS design will take benefit by an adequate modeling of self-consistent wave absorption simulations.
Finite Element Analysis of the Schroedinger Equation
Avtar S. Sehra
2007-04-17
The purpose of this work is to test the application of the finite element method to quantum mechanical problems, in particular for solving the Schroedinger equation. We begin with an overview of quantum mechanics, and standard numerical techniques. We then give an introduction to finite element analysis using the diffusion equation as an example. Three numerical time evolution methods are considered: the (tried and tested) Crank-Nicolson method, the continuous space-time method, and the discontinuous space-time method.
Scalability Analysis of Partitioning Strategies for Finite Element Graphs. \\Lambda
Kumar, Vipin
Scalability Analysis of Partitioning Strategies for Finite Element Graphs. \\Lambda Grama Y. Ananth Y. Grama ananth@cs:umn:edu Abstract Issues of partitioning Finite Element Graphs are central for implementing the Finite Element Method (FEM). Parallel formulations of finite element techniques require
DOLFIN: Automated Finite Element Computing
Logg, Anders; Wells, G N
2009-01-01
´de´lec 1980]. (4) L2-conforming finite elements: (a) DGq, arbitrary degree discontinuous Lagrange elements; and (b) CR1, first degree Crouzeix–Raviart5 elements [Crouzeix and Raviart 1973]. Arbitrary combinations of the above elements may be used to define...
Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation
Wells, G N
2009-10-29
is denoted by ?0. Adjacent cells are considered to share a common facet F . The bilinear and linear forms for the advection-diffusion-reaction equation are now introduced. Using the notation w = (w, w¯) and v = (v, v¯), consider the bilinear form: B (w... ? h , the finite element problem of interest reads: find uh ?W ?h such that B (uh,vh) = L (vh) ?vh ?W ?h . (2.8) Noteworthy in the bilinear form is that the functions wh, which are discontinuous across cell facets, are not linked directly across facets...
B-spline finite elements for plane elasticity problems
Aggarwal, Bhavya
2007-04-25
The finite element method since its development in the 1950Ã¢Â?Â?s has been used extensively in solving complex problems involving partial differential equations. The conventional finite element methods use piecewise ...
X. Frank Xu
2010-03-30
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.
Nonconforming finite element methods for the simulation of waves in viscoelastic solids
Sheen, Dongwoo
a , Juan E. Santos b , Dongwoo Sheen c,* a School of Civil, Urban, and Geosystem Engineering, Seoul of waves in two- and three-dimensional bounded viscoelastic media is described in the space frequency element methods are employed for the spatial discretization. Optimal error estimate in a broken energy
Finite Element Analysis in Functional BRIAN G. RICHMOND,1
Finite Element Analysis in Functional Morphology BRIAN G. RICHMOND,1 * BARTH W. WRIGHT,1 IAN GROSSE element analysis. © 2005 Wiley-Liss, Inc. Key words: finite-element analysis; mastication; primates; biome This article reviews the fundamental principles of the finite element method and the three basic steps (model
Massively Parallel Computing: Unstructured Finite Element Simulations
Johnsson, S. Lennart
of NAFEM 4th International Conference on Quality Assurance and Standards in Finite Element and Associated
k - Version of Finite Element Method for Polymer flows using Giesekus Constitutive Model
Deshpande, Kedar M.
2008-01-31
= Velocity in x direction v = Dimensionless Velocity in x direction ??xx = Normal Stress in x direction ?xx = Dimensionless Normal Stress in x direction ??yy = Normal Stress in y direction ?yy = Dimensionless Normal Stress in y direction ??xy = Shear Stress... of Pressure p over an element primeeprime ?hxx = Interpolation of normal stress ?xx over an element primeeprime ?hyy = Interpolation of normal stress ?yy over an element primeeprime ?hxy = Interpolation of shear stress ?xy over an element primeeprime ??p...
Zingan, Valentin Nikolaevich
2012-07-16
This work develops a discontinuous Galerkin finite element discretization of non- linear hyperbolic conservation equations with efficient and robust high order stabilization built on an entropy-based artificial viscosity approximation...
Yu, Guangbin [The Higher Educational Key Laboratory for Measuring and Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080 (China); Tang, Chaolong [Department of Metallurgical and Materials Engineering, Center for Materials for Information Technology (MINT), University of Alabama, Tuscaloosa, Alabama 35487 (United States); Song, Jinhui, E-mail: jhsong@eng.ua.edu, E-mail: wqlu@cigit.ac.cn [The Higher Educational Key Laboratory for Measuring and Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714 (China); Department of Metallurgical and Materials Engineering, Center for Materials for Information Technology (MINT), University of Alabama, Tuscaloosa, Alabama 35487 (United States); Lu, Wenqiang, E-mail: jhsong@eng.ua.edu, E-mail: wqlu@cigit.ac.cn [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714 (China)
2014-04-14
Based on conductivity characterization of single crystal zinc oxide (ZnO) micro/nanobelt (MB/NB), we further investigate the physical mechanism of nonlinear intrinsic resistance-length characteristic using finite element method. By taking the same parameters used in experiment, a model of nonlinear anisotropic resistance change with single crystal MB/NB has been deduced, which matched the experiment characterization well. The nonlinear resistance-length comes from the different electron moving speed in various crystal planes. As the direct outcome, crystallography of the anisotropic semiconducting MB/NB has been identified, which could serve as a simple but effective method to identify crystal growth direction of single crystal semiconducting or conductive nanomaterial.
Blacker, Teddy D. (12205 Kashmir, N.E., Albuquerque, NM 87111)
1994-01-01
An automatic quadrilateral surface discretization method and apparatus is provided for automatically discretizing a geometric region without decomposing the region. The automated quadrilateral surface discretization method and apparatus automatically generates a mesh of all quadrilateral elements which is particularly useful in finite element analysis. The generated mesh of all quadrilateral elements is boundary sensitive, orientation insensitive and has few irregular nodes on the boundary. A permanent boundary of the geometric region is input and rows are iteratively layered toward the interior of the geometric region. Also, an exterior permanent boundary and an interior permanent boundary for a geometric region may be input and the rows are iteratively layered inward from the exterior boundary in a first counter clockwise direction while the rows are iteratively layered from the interior permanent boundary toward the exterior of the region in a second clockwise direction. As a result, a high quality mesh for an arbitrary geometry may be generated with a technique that is robust and fast for complex geometric regions and extreme mesh gradations.
Nguyen, Dang Van; Li, Jing-Rebecca; Grebenkov, Denis; Le Bihan, Denis
2014-04-15
The complex transverse water proton magnetization subject to diffusion-encoding magnetic field gradient pulses in a heterogeneous medium can be modeled by the multiple compartment Bloch–Torrey partial differential equation (PDE). In addition, steady-state Laplace PDEs can be formulated to produce the homogenized diffusion tensor that describes the diffusion characteristics of the medium in the long time limit. In spatial domains that model biological tissues at the cellular level, these two types of PDEs have to be completed with permeability conditions on the cellular interfaces. To solve these PDEs, we implemented a finite elements method that allows jumps in the solution at the cell interfaces by using double nodes. Using a transformation of the Bloch–Torrey PDE we reduced oscillations in the searched-for solution and simplified the implementation of the boundary conditions. The spatial discretization was then coupled to the adaptive explicit Runge–Kutta–Chebyshev time-stepping method. Our proposed method is second order accurate in space and second order accurate in time. We implemented this method on the FEniCS C++ platform and show time and spatial convergence results. Finally, this method is applied to study some relevant questions in diffusion MRI.
A study of arbitrary rotations of shells of revolution by the finite element method
Rosenbaum, James Byron
1974-01-01
were reduced to eiskf3, ez3kz~, and the squares and products of the two. This contributed rotation effects to the nonlinear strain energy which previously had not been taken into account. As a computational time saver, the partial derivatives... II-1 III-1 IV-1 Geometry of Shell of Revolution Segment. . Coordinization of Shell Element. . Comparison of SNASOR III with New SNASOR III for a Shallow Shell of X = 6. Page 14 26 31 IV-2 Buckling Analysis of Higher Order Strain Energy...
Partition-of-unity finite-element method for large scale quantum...
Office of Scientific and Technical Information (OSTI)
can be investigated by such accurate, quantum mechanical means. The current state of the art for large-scale quantum simulations is the planewave (PW) method, as implemented in now...
Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method
Wang, G.; Liu, M.
2005-01-01
A method, based on simulation models, for active functional tests and optimization of coil energy recovery loop systems in Air Handling Units (AHUs) have been developed and a first version implemented in the program Engineering Equation Solver (EES...
A 3D finite element method for flexible multibody Johannes Gerstmayr, Joachim Schoberl
Schoeberl, Joachim
-Kutta scheme. The present method has been imple- mented and tested with the FE-package NETGEN/NGSOLVE. Keywords dynamics, e.g. for the investigation of a slider-crank mechanism [9], the stability of a rotor-blade of a helicopter or the stability of a satellite with highly flexible solar panels, see Bremer [5]. While most
A TWODIMENSIONAL MOVING FINITE ELEMENT METHOD WITH LOCAL REFINEMENT BASED ON A POSTERIORI ERROR
Cao, Weiming
and Flaherty [1] to the twodimensional case, where clusters of mesh points are built up and moved (middle), and rhrefinement with N = 541 yields e L2() = 1.57E-2 (right). While the rmethod wastes too
A stabilized stochastic finite element second-order projection method for modeling
Zabaras, Nicholas J.
of freedom. Because of the porosity dependence of the pressure gradient term in the governing flow equations-order projection method is presented based on a pressure gradient projection. A two- dimensional stochastic problem occurring in var- ious applications such as fluidized beds, solidification of alloys, geothermal energy
Bailey, Teresa S
2008-10-10
) 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-transfer problems in radiation-hydrodynamics systems... ..................................................................... 7 II AN INTRODUCTION TO RADIATION HYDRODYNAMICS....... 10 The Euler equations........................................................................ 10 The radiative transfer equations...
DOLFIN: Automated finite element computing
Logg, Anders; Wells, G N
2009-02-25
, and in particular the C++ Technical Report 1 (TR1) std::tr1::shared ptr and Boost boost:shared ptr (DOLFIN currently uses boost:shared ptr since this is better supported by SWIG than is std::tr1::shared ptr). In managing data sharing, this solution has reduced... . DOLFIN: Automated Finite Element Computing · 7 3. DESIGN CONSIDERATIONS The successful development of DOLFIN has been driven by two keys factors. The first is striving for technical innovation. Examples of this include the use of a form compiler...
Shahri, Mehdi Abbaszadeh
2006-04-12
Stability????.?????? 25 5.2 Wellbore Stability in Shale???..??????????.. 26 5.3 Various Instability Risk Criteria?.???????.???. 27 5.4 Borehole Stability Analysis?????????????.. 27 CHAPTER VI..., to the manifold methods of mining ore and aggregate materials, to the stability of petroleum wellbores, and including newer applications such as geothermal energy and radioactive waste disposal. 1.1 Importance of Primary Cementing on Cost Avoiding remedial...
Suresh, Krishnan
Submitted to: Finite Elements in Analysis and Design 1 Finite Element Analysis over Tangled element theory and commercial FEA packages are not designed to handle tangled meshes, i.e., they can lead element). Modern finite element theory and commercial FEA packages are not designed to handle tangled
Student Award Competition Finite Element EEG and MEG Simulations for Realistic Head Models
Zhukov, Leonid
than would be possible using linear elements alone. [1] D.S. Burnett. Finite Element Analysis: FromStudent Award Competition Finite Element EEG and MEG Simulations for Realistic Head Models be approximated by a technique such as the finite element method [1]. Most applications of the finite element
Mathur, Anuj
1994-01-01
In this work we study the pollution-error in the h-version of the finite element method and its effect on the local quality of a-posteriori error estimators. We show that the pollution-effect in an interior subdomain depends on the relationship...
Rumpf, Martin
15th Workshop on the Finite Element Method in Biomedical Engineering, Biomechanics and Related A microstructured material of special biomechanical interest is human trabecular bone which is mainly located.rumpf,ole.schwen}@ins.uni-bonn.de Institute of Orthopaedic Research and Biomechanics, University of Ulm {hans
RodrÃguez, Rodolfo
Â´on, Chile. This paper deals with the approximation of the bending of a clamped plate modeled by ReissnerNumerical analysis of a locking-free mixed finite element method for a bending moment formulation the thickness t is small. Here, we propose a new mixed formulation in terms of the bending moments, shear stress
Construction of Higher Order Finite Element with
Kern, Michel
' & $ % Construction of Higher Order Finite Element with Mass Lumping Using Computer Algebra. (3D, combinatorial analysis, new third order element) 2 #12; ' & $ % Guidelines for the construction of nodes must be ~ P k unisolvent. 2. Finite element must be continuous. 3. Quadrature formula must satisfy
Williams, P.T.
1993-09-01
As the field of computational fluid dynamics (CFD) continues to mature, algorithms are required to exploit the most recent advances in approximation theory, numerical mathematics, computing architectures, and hardware. Meeting this requirement is particularly challenging in incompressible fluid mechanics, where primitive-variable CFD formulations that are robust, while also accurate and efficient in three dimensions, remain an elusive goal. This dissertation asserts that one key to accomplishing this goal is recognition of the dual role assumed by the pressure, i.e., a mechanism for instantaneously enforcing conservation of mass and a force in the mechanical balance law for conservation of momentum. Proving this assertion has motivated the development of a new, primitive-variable, incompressible, CFD algorithm called the Continuity Constraint Method (CCM). The theoretical basis for the CCM consists of a finite-element spatial semi-discretization of a Galerkin weak statement, equal-order interpolation for all state-variables, a 0-implicit time-integration scheme, and a quasi-Newton iterative procedure extended by a Taylor Weak Statement (TWS) formulation for dispersion error control. Original contributions to algorithmic theory include: (a) formulation of the unsteady evolution of the divergence error, (b) investigation of the role of non-smoothness in the discretized continuity-constraint function, (c) development of a uniformly H{sup 1} Galerkin weak statement for the Reynolds-averaged Navier-Stokes pressure Poisson equation, (d) derivation of physically and numerically well-posed boundary conditions, and (e) investigation of sparse data structures and iterative methods for solving the matrix algebra statements generated by the algorithm.
Finite Element Modeling of Drilling Using DEFORM
Gardner, Joel D.; Dornfeld, David
2006-01-01
Vijayaraghavan, A. (2005), “Drilling of Fiber- ReinforcedFINITE ELEMENT MODELING OF DRILLING USING DEFORM J. Gardner,of Comprehensive Drilling Simulation Tool” ABSTRACT DEFORM-
Plane-wave fluorescence tomography with adaptive finite elements
Bangerth, Wolfgang
Plane-wave fluorescence tomography with adaptive finite elements Amit Joshi Photon Migration reflectance imaging setup. The method employs planar illumination with modulated light and frequency domain fluo- rescence measurements made on the illumination plane. An adaptive finite-element algorithm
A PROBABILISTIC FINITE ELEMENT ANALYSIS OF RESIDUAL STRESS FORMATION
Grujicic, Mica
A PROBABILISTIC FINITE ELEMENT ANALYSIS OF RESIDUAL STRESS FORMATION IN SHRINK-FIT CERAMIC shrink fitting of the jacket over the lining is studied using a probabilistic finite element analysis structural analysis approach, known as the Advanced Mean Value (AMV) method, is used which enables
Probabilistic slope stability analysis by finite elements D.V. Griffiths*
Probabilistic slope stability analysis by finite elements D.V. Griffiths* and Gordon A. Fenton. The advanced method, called the random finite element method (RFEM), uses elasto- plasticity combined nonlinear finite element methods are combined with ran- dom field generation techniques. This method, called
Benchmarking of finite element codes for radioactive material transportation packages
Ammerman, D.J.
1996-10-01
The increased power of computers and computer codes makes the use of nonlinear dynamic finite element analyses attractive for use as a tool used in the design and certification of radioactive material transportation packages. For this analysis technique to be acceptable it must be demonstrated. The technique has the ability to accurately capture the response of the packages to accident environments required by the regulations. The best method of demonstrating this ability is via a series of benchmark analyses. In this paper three benchmark problems involving significant inelastic deformations will be discussed. One of the problems has been analyzed using many different finite element codes. The other two problems involve comparison of finite element calculations to the results form physical tests. The ability of the finite element method to accurately capture the response in these three problems indicates the method should be acceptable for radioactive material transportation package design and certification.
Finite element analysis of multilayer coextrusion.
Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A.; Mrozek, Randy A.; Lenhart, Joseph Ludlow; Rao, Rekha Ranjana; Collins, Robert; Mondy, Lisa Ann
2011-09-01
Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.
Optimal convergence analysis for the eXtended Finite Element Serge Nicaise 1
Paris-Sud XI, Université de
Optimal convergence analysis for the eXtended Finite Element Method Serge Nicaise 1 , Yves Renard 2Xtended Finite Element Method (Xfem), namely the Xfem with a cut-off function and the stan- dard Xfem finite element method, error estimates, stress intensity factors. 1 Introduction Inspired by the Pufem
Cheng, C.Z.
1988-12-01
A nonvariational ideal MHD stability code (NOVA) has been developed. In a general flux coordinate (/psi/, theta, /zeta/) system with an arbitrary Jacobian, the NOVA code employs Fourier expansions in the generalized poloidal angle theta and generalized toroidal angle /zeta/ directions, and cubic-B spline finite elements in the radial /psi/ direction. Extensive comparisons with these variational ideal MHD codes show that the NOVA code converges faster and gives more accurate results. An extended version of NOVA is developed to integrate non-Hermitian eigenmode equations due to energetic particles. The set of non-Hermitian integro-differential eigenmode equations is numerically solved by the NOVA-K code. We have studied the problems of the stabilization of ideal MHD internal kink modes by hot particle pressure and the excitation of ''fishbone'' internal kink modes by resonating with the energetic particle magnetic drift frequency. Comparisons with analytical solutions show that the values of the critical ..beta../sub h/ from the analytical theory can be an order of magnitude different from those computed by the NOVA-K code. 24 refs., 11 figs., 1 tab.
Jimack, Peter
On the linear finite element analysis of fully-coupled point contact elastohydrodynamic lubrication lubrication (EHL) point contact problems requires the numerical solution of the elasticity prob- lem, technique is applied. KEYWORDS: elastohydrodynamic lubrication; finite element method; linear elasticity
Jimack, Peter
An adaptive finite element procedure for fully-coupled point contact elastohydrodynamic lubrication to control adaptivity in both the elasticity and the lubrication domains. The implementation is based levels grows. KEYWORDS: elastohydrodynamic lubrication; finite element method; linear elasticity; fully
Bonet, J.
We present an implicit a-posteriori finite element procedure to compute bounds for functional outputs of finite element solutions in large strain elasticity. The method proposed relies on the existence of a potential energy ...
2.094 Finite Element Analysis of Solids and Fluids, Spring 2008
Kim, Do-Nyun
This course presents finite element theory and methods for general linear and nonlinear analyses. Reliable and effective finite element procedures are discussed with their applications to the solution of general problems ...
FULLYDISCRETE FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY
Ewing, Richard E.
FULLYDISCRETE FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY Zhangxin Chen element method for a nonlinear differential system for describing an airwater system in groundwater experiments using the present approach for modeling groundwater flow in porous media are reported. Key words
Modeling Elastic Properties in Finite-Element Analysis: How Much
Modeling Elastic Properties in Finite- Element Analysis: How Much Precision Is Needed to Produce analysis was investigated using a finite-element model of a Macaca fascicularis skull. Four finite-element realistically using the orthotropic elastic properties employed in analysis 4. Results suggest that finite-element
Techniques for Modeling Muscle-Induced Forces in Finite Element
Dumont, Elizabeth R.
program was written to interface with a commercial finite element analysis tool to automatically apply: finite element analysis; muscle force; skull; muscle loading alogorithm, biting Finite element analysisTechniques for Modeling Muscle- Induced Forces in Finite Element Models of Skeletal Structures IAN
Finite Elements in Analysis and Design 42 (2006) 580591 www.elsevier.com/locate/finel
Li, Shaofan
2006-01-01
Finite Elements in Analysis and Design 42 (2006) 580591 www.elsevier.com/locate/finel A variational multiscale stabilized finite element method for the Stokes flow problem Xiaohu Liu , Shaofan Li order Finite Element intepolation pairs and has a formulation similar to the one of Galerkin
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models
Sarkar, Sudeep
Nonrigid Motion Analysis Based on Dynamic Refinement of Finite Element Models Leonid V. Tsap finite element models. The method is based on the iterative analysis of the differences betweenÃPhysically-based vision, deformable models, nonrigid motion analysis, biomedical applications, finite element analysis. Ã¦
A cracked beam finite element for rotating shaft dynamics and stability analysis
Paris-Sud XI, Université de
A cracked beam finite element for rotating shaft dynamics and stability analysis Saber El Arem Palaiseau, France Abstract In this paper, a method for the construction of a cracked beam finite element is presented. The additional flexibility due to the cracks is identified from three- dimensional finite element
Gieras, J.F.; Wing, M. [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering] [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering; Santini, E. [Univ. of Rome (Italy). Dept. of Electrical Engineering] [Univ. of Rome (Italy). Dept. of Electrical Engineering
1998-09-01
The synchronous reactances of permanent magnet (PM) motors have been determined using: (1) analytical method, i.e., form factors of the stator field (armature reaction factors), (2) finite element method (FEM), and (3) experimental tests on a special machine set. The analytical method is widely used in calculations of synchronous reactances of salient pole synchronous machines with electromagnetic excitation. Rotors of PM synchronous machines have more complicated structures, hence it is more difficult to predict accurately the magnetic field distribution in their airgaps in order to find the form factors of the stator field. Numerical methods of field analysis can easily solve this problem. The FEM can predict both the synchronous and mutual (armature reaction) reactances in the d and q axes. The leakage reactance can then be evaluated as a difference between synchronous and mutual reactances. As an example, a small, three-phase, four-pole motor with SmCo surface mounted PM`s (three parallel magnets per pole), and mild-steel pole shoes has been investigated. Such a complicated rotor structure has been intentionally designed in order to be able to compare the advantages and disadvantages of the analytical method and the FEM. In the FEM, the reactances have been calculated using both the flux linkage and current/energy perturbation method. Synchronous reactances as functions of the stator current and load angle obtained analytically from the FEM modeling and from measurements have been compared.
Finite element methods for 3D eddy current prob-lems in bounded domains subject to realistic
Rodríguez, Rodolfo
devices such us electrical machines, induction heating systems, transformers, waveguides, microwaves, etc formulations based on the magnetic or the electric field, approximated by means of edge elements. The most electric furnaces are discussed and numerical results are given. 1 INTRODUCTION Numerical simulation plays
Dennis, Eberhart, Dulikravich & Radons FINITE ELEMENT SIMULATION OF COOLING
Dennis, Brian
1 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 is a potentially attractive preservation method. This computer modeling study was undertaken to examine brain-cooling
Yosibash, Zohar
1997-01-01
; Beer-Sheva; Israel SUMMARY This paper presents a new method for accurate pointwise stress extraction value stresses. The method, denoted by SEC (Stress Extraction by Complementary principle), is based, and indirect extraction methods should be sought. Indirect computation of stresses have been shown
An Augmented Lagrangian Mixed Finite Element Scheme for Saddle Point Problems \\Lambda
Yang, Daoqi
on the idea of iteratively penalizing the mixed finite element scheme. It is shown that the scheme has \\Delta /dx: Its mixed finite element approximations consist of constructing finite dimensional spaces [5 ); (9) where \\Pi is the L 2 projection operator onto Q. The convergence for this method is ku \\Gamma um
The Uranium Processing Facility (UPF) Finite Element Meshing Discussion
Broader source: Energy.gov [DOE]
The Uranium Processing Facility (UPF) Finite Element Meshing Discussion Loring Wyllie Arne Halterman Degenkolb Engineers, San Francisco
Guerin, P.; Baudron, A. M.; Lautard, J. J.
2006-07-01
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)
Analysis of PostProcessing for Nonconforming Finite Element Solutions
Schieweck, Friedhelm
Analysis of PostProcessing for Nonconforming Finite Element Solutions F. Schieweck \\Lambda of a conforming finite element function v C h 2 V C h . One ``nice'' feature of our analysisprocessing procedure where a conforming approximation is computed from a nonconforming finite element solution
STATIC ANALYSIS OF SANDWICH PLATES BY FINITE ELEMENTS
Paris-Sud XI, Université de
STATIC ANALYSIS OF SANDWICH PLATES BY FINITE ELEMENTS V. MANET, W.-S. HAN AND A. VAUTRIN ´Ecole des continuity at hal-00663233,version1-26Jan2012 #12;Static analysis of sandwich plates by finite elements 3 and are presented in this paper. 2. Hybrid sandwich finite elements In this section, we present the development
Modeling Masticatory Muscle Force in Finite Element Analysis
Modeling Masticatory Muscle Force in Finite Element Analysis: Sensitivity Analysis Using Principal: electromyography; muscle force; mastication; primates; principal coordinates analysis; finite element analysis Our Origins, University of Arizona, Tempe, Arizona ABSTRACT Our work on a finite element model of the skull
Medially Based Meshing with Finite Element Analysis of Prostate Deformation
Crouch, Jessica R.
Medially Based Meshing with Finite Element Analysis of Prostate Deformation Jessica R. Crouch1 have approached prostate imaging problems using meth- ods that incorporate finite element analysis. Assume the prostate is a linearly elastic body and compute its deformation using finite element analysis
Automated Finite Element Analysis for Deformable Registration of Prostate Images
1 Automated Finite Element Analysis for Deformable Registration of Prostate Images Jessica R, Marco Zaider Abstract-- Two major factors preventing the routine clinical use of finite element analysis the effort required to apply finite element analysis to image registration. Encouraging results are presented
FINITE ELEMENT ANALYSIS OF A CLASS OF STRESSFREE MARTENSITIC MICROSTRUCTURES
Li, Bo
FINITE ELEMENT ANALYSIS OF A CLASS OF STRESSFREE MARTENSITIC MICROSTRUCTURES BO LI Abstract. This work is concerned with the finite element approximation of a class of stressfree martensitic microstructures modeled by multiwell en ergy minimization. Finite element energyminimizing sequences are first
A finite element analysis of pneumatic-tire/sand interactions
Grujicic, Mica
A finite element analysis of pneumatic-tire/sand interactions during off-road vehicle travel M pneumatic tire and sand during off-road vehicle travel. Keywords Finite element analysis, Road vehicles and for other tire/sand combinations. Since the finite element analysis of the tire/sand interaction enables
Static Analysis of Sandwich Plates by Hybrid Finite Elements
Paris-Sud XI, Université de
Static Analysis of Sandwich Plates by Hybrid Finite Elements V. Manet and W.-S. Han Materials analysis tool. The subject of the present work concerns the development of hybrid sandwich finite elements into acount. The present work concerns the development of hybrid sandwich finite elements mod- elling
Building Finite Element Analysis Programs in Distributed Services Environment
Stanford University
1. Building Finite Element Analysis Programs in Distributed Services Environment Jun Peng1 and Kincho H. Law2 Abstract Traditional finite element analysis (FEA) programs are typically built on a dedicated computer using the developments offered by a finite element analysis (FEA) program. Typically
hp-finite-elements for simulating electromagnetic fields in optical devices with rough textures
Burger, S; Hammerschmidt, M; Herrmann, S; Pomplun, J; Schmidt, F; Wohlfeil, B; Zschiedrich, L
2015-01-01
The finite-element method is a preferred numerical method when electromagnetic fields at high accuracy are to be computed in nano-optics design. Here, we demonstrate a finite-element method using hp-adaptivity on tetrahedral meshes for computation of electromagnetic fields in a device with rough textures. The method allows for efficient computations on meshes with strong variations in element sizes. This enables to use precise geometry resolution of the rough textures. Convergence to highly accurate results is observed.
SYMMETRIC NON-CONFORMING MIXED FINITE ELEMENTS FOR LINEAR ELASTICITY
GuzmÃ¡n, Johnny
. However, stress elements are difficult to design due to two requirements. First, due to conservation finite elements satisfying both these requirements have been designed in [1, 8, 4, 3]. But the mainSYMMETRIC NON-CONFORMING MIXED FINITE ELEMENTS FOR LINEAR ELASTICITY J. GOPALAKRISHNAN AND J. GUZM
The Uranium Processing Facility Finite Element Meshing Discussion
Office of Environmental Management (EM)
Uranium Processing Facility (UPF) Finite Element Meshing Discussion ...Need picture of Building... October 25, 2011 Department of Energy - Natural Phenomenon Hazard Workshop 1...
Finite Elements in Analysis and Design 40 (2004) 16191640 www.elsevier.com/locate/nel
Ghosh, Somnath
2004-01-01
Finite Elements in Analysis and Design 40 (2004) 16191640 www.elsevier.com/locate/ÿnel Two scale. Raghavan et al. / Finite Elements in Analysis and Design 40 (2004) 16191640 performed by the method-scale analysis of composite structures with non-uniform microstructural heterogeneities as obtained from optical
FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION
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
Mihaila, Bogdan
TO -URANIUM Marko Knezevic, Rodney J. McCabe, Ricardo A. Lebensohn, Carlos N. Tomé, and Bogdan Mihaila Keywords: Uranium; Constitutive modeling; Finite Element Method Abstract We present an improved mechanical response of wrought -uranium. In this regard, a finite element integration point is considered
Energy conserving Anisotropic Anhysteretic Magnetic Modelling for Finite Element Analysis
Jens Krause
2012-12-20
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.
Adaptive Finite Elements and Colliding Black Holes
Douglas N. Arnold; Arup Mukherjee; Luc Pouly
1997-09-15
According to the theory of general relativity, the relative acceleration of masses generates gravitational radiation. Although gravitational radiation has not yet been detected, it is believed that extremely violent cosmic events, such as the collision of black holes, should generate gravity waves of sufficient amplitude to detect on earth. The massive Laser Interferometer Gravitational-wave Observatory, or LIGO, is now being constructed to detect gravity waves. Consequently there is great interest in the computer simulation of black hole collisions and similar events, based on the numerical solution of the Einstein field equations. In this note we introduce the scientific, mathematical, and computational problems and discuss the development of a computer code to solve the initial data problem for colliding black holes, a nonlinear elliptic boundary value problem posed in an unbounded three dimensional domain which is a key step in solving the full field equations. The code is based on finite elements, adaptive meshes, and a multigrid solution process. Here we will particularly emphasize the mathematical and algorithmic issues arising in the generation of adaptive tetrahedral meshes.
Adaptive High-order Finite Element Solution of Transient Elastohydrodynamic Lubrication
Walkley, Mark
Adaptive High-order Finite Element Solution of Transient Elastohydrodynamic Lubrication Problems H a new numerical method to solve transient line contact elastohydrodynamic lubrication (EHL) problems parameter dimensionless density 2 #12;1 Introduction Elastohydrodynamic Lubrication (EHL) problems have
Finite Element Modelling and Molecular Dynamic Simulations of Carbon nanotubes/ Polymer Composites
Gaddamanugu, Dhatri
2010-07-14
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...
Finite element decomposition and grid generation for brain modeling and visualization
Batte, David Allan
1997-01-01
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...
Gogineni, Sireesha
2011-10-21
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...
Biffle, J.H.
1993-02-01
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.
Finite-volume matrix elements in multiboson states
Detmold, William
We derive the relations necessary for the extraction of matrix elements of multihadron systems from finite-volume lattice QCD calculations. We focus on systems of n ? 2 weakly interacting identical particles without spin. ...
1 INTRODUCTION Nowadays, geomechanical finite-element codes
Paris-Sud XI, Université de
1 INTRODUCTION Nowadays, geomechanical finite-element codes running on modern computers allow for years. Geotechnical characterization, geophysical surveys and geomechanical modelling have been in geomechanical modelling. In particular, seismic and borehole data, obtained during previous campaigns, are used
Spectral/hp Finite Element Models for Fluids and Structures
Payette, Gregory
2012-07-16
for the numerical simulation of the fully geometrically nonlinear mechanical response of isotropic, laminated composite and functionally graded elastic shell structures. In addition, we also present a simple and efficient sparse global finite element coefficient...
Finite element study of Lamb waves: modeling techniques and applications
Verdict, Gregory Scott
1993-01-01
and theoretical results. In addition, other finite element work shows the viability of using these modeling techniques as a tool for understanding the interaction of Lamb waves with physical defects. As a signal processing tool, neural networks will process...
NORTHWESTERN UNIVERSITY Finite Element Analysis of TDR Cable-Grout-Soil Mass
NORTHWESTERN UNIVERSITY Finite Element Analysis of TDR Cable-Grout-Soil Mass Interaction During............................................................................................ 13 Finite Element Analysis of Cable Shear Test............................................................................................ 22 Finite Element Analysis of Grout-Cable Composite Shear Test .................................. 25
Finite Element Approximation of the Acoustic Wave Equation: Error Control and Mesh
Bangerth, Wolfgang
Finite Element Approximation of the Acoustic Wave Equation: Error Control and Mesh Adaptation of the Acoustic Wave Equation: Error Control and Mesh Adaptation Wolfgang Bangerth and Rolf Rannacher1 Institute@iwr.uni-heidelberg.de Abstract We present an approach to solving the acoustic wave equation by adaptive finite el- ement methods
Progress in Developing Finite Element Models Replicating Flexural Graphite Testing
Robert Bratton
2010-06-01
This report documents the status of flexural strength evaluations from current ASTM procedures and of developing finite element models predicting the probability of failure. This work is covered under QLD REC-00030. Flexural testing procedures of the American Society for Testing and Materials (ASTM) assume a linear elastic material that has the same moduli for tension and compression. Contrary to this assumption, graphite is known to have different moduli for tension and compression. A finite element model was developed and demonstrated that accounts for the difference in moduli tension and compression. Brittle materials such as graphite exhibit significant scatter in tensile strength, so probabilistic design approaches must be used when designing components fabricated from brittle materials. ASTM procedures predicting probability of failure in ceramics were compared to methods from the current version of the ASME graphite core components rules predicting probability of failure. Using the ASTM procedures yields failure curves at lower applied forces than the ASME rules. A journal paper was published in the Journal of Nuclear Engineering and Design exploring the statistical models of fracture in graphite.
Surface photovoltage measurements and finite element modeling of SAW devices.
Donnelly, Christine
2012-03-01
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.
Lin, Liwei
Introduction to Finite Element Modeling Engineering analysis of mechanical systems have been of the FEM (don't misuse the FEM - a numerical tool) Finite Element Analysis A typical finite element quantities (e.g., strains and stresses) at selected elements Basic Theory The way finite element analysis
Experimental and finite element analysis of high pressure packer elements
Berger, Stephanie, 1981-
2004-01-01
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 ...
FINITE ELEMENTS AND FINITE DIFFERENCE HUMAN HEAD MODELING: FORWARD PROBLEM
Lowd, Daniel
.T. Vetterling, B.P. Flannery, The Numerical Recipes in C: The art of Scientific Computing, 2nd edition. New York/MEG Fundamental problems in electroencephalography (EEG) and magnetoencephalograpy (MEG), in particular , source DISCUSSION AND FUTURE RESEARCH When using FD methods one should be aware about the following "pros" and "cons
Nonlinear Legendre Spectral Finite Elements for Wind Turbine Blade Dynamics: Preprint
Wang, Q.; Sprague, M. A.; Jonkman, J.; Johnson, N.
2014-01-01
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.
AN ADAPTIVE EDGE ELEMENT METHOD WITH PERFECTLY ...
2009-09-15
May 7, 2009 ... Scattering theory in biperiodic structures has many important .... the PML error and the finite element discretization error, is used to design.
Diffusive mesh relaxation in ALE finite element numerical simulations
Dube, E.I.
1996-06-01
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.
Experimentally validated finite element model of electrocaloric multilayer ceramic structures
Smith, N. A. S. E-mail: maciej.rokosz@npl.co.uk Correia, T. M. E-mail: maciej.rokosz@npl.co.uk; Rokosz, M. K. E-mail: maciej.rokosz@npl.co.uk
2014-07-28
A novel finite element model to simulate the electrocaloric response of a multilayer ceramic capacitor (MLCC) under real environment and operational conditions has been developed. The two-dimensional transient conductive heat transfer model presented includes the electrocaloric effect as a source term, as well as accounting for radiative and convective effects. The model has been validated with experimental data obtained from the direct imaging of MLCC transient temperature variation under application of an electric field. The good agreement between simulated and experimental data, suggests that the novel experimental direct measurement methodology and the finite element model could be used to support the design of optimised electrocaloric units and operating conditions.
Grujicic, Mica
2005-01-01
Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design A finite element method-based procedure is developed for the design of molecularly functionalized nano of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure
California at Berkeley, University of
APPLICATIONS OF ALGEBRAIC MULTIGRID TO LARGE-SCALE FINITE ELEMENT ANALYSIS OF WHOLE BONE MICRO,5 Abstract. Accurate micro-finite element analyses of whole bones require the solution of large sets architectures. Key words. multigrid, trabecular bone, human vertebral body, finite element method, massively
Torres-Verdín, Carlos
Mathematics, Bizkaia Technology Park, Building 500, 48160 Derio, Spain. 3 Department of Petroleum element. The algorithm automatically performs local mesh refinement to construct an optimal grid
Cut-on cut-off transition in flow ducts: comparing multiple-scales and finite-element solutions
Eindhoven, Technische Universiteit
Cut-on cut-off transition in flow ducts: comparing multiple-scales and finite-element solutions Eindhoven, The Netherlands. The phenomenon of cut-on cut-off transition of acoustic modes in ducts with mean from a numerical finite-element method. The analytical solution, derived for an arbitrary duct
Paris-Sud XI, Université de
2002-01-01
J. Sulem & M. Cerrolaza (2002): Finite element analysis of the indentation test on rocks with microstructure 1 FINITE ELEMENT ANALYSIS OF THE INDENTATION TEST ON ROCKS WITH MICROSTRUCTURE Published in-117" #12;J. Sulem & M. Cerrolaza (2002): Finite element analysis of the indentation test on rocks
High Order Finite Element Solution of Elastohydrodynamic Lubrication Problems
Jimack, Peter
High Order Finite Element Solution of Elastohydrodynamic Lubrication Problems by Hongqiang Lu-dimensional Elastohydro- dynamic Lubrication (EHL) problems (line contact and point contact). This thesis pro- vides an introduction to elastohydrodynamic lubrication, including some history, and a description of the underlying
Medially Based Meshing with Finite Element Analysis of Prostate Deformation
Crouch, Jessica R.
brachytherapy seeds are presented. 1 Introduction This paper considers finite element techniques for non-rigidly registering three- dimensional prostate images acquired for the purpose of brachytherapy plan- ning and guidance. Brachytherapy involves implanting radioactive seeds in the prostate to treat prostate cancer
Finite Element Model of Fracture Formation on Growing Surfaces
Prusinkiewicz, Przemyslaw
Finite Element Model of Fracture Formation on Growing Surfaces Pavol Federl and Przemyslaw-mail: federl|pwp@cpsc.ucalgary.ca Abstract We present a model of fracture formation on surfaces of bilayered materials. The model makes it possible to synthesize patterns of fractures induced by growth or shrinkage
FINITE ELEMENT ANALYSIS OF THERMAL TENSIONING TECHNIQUES MITIGATING WELD BUCKLING DISTORTION
Michaleris, Panagiotis
FINITE ELEMENT ANALYSIS OF THERMAL TENSIONING TECHNIQUES MITIGATING WELD BUCKLING DISTORTION. This paper presents a finite element analysis model of the thermal tensioning technique. A series of finite by the finite element simulations, the residual stresses of large size and high heat input welds are reduced
SUBDIVISION SURFACES: A NEW PARADIGM FOR THIN-SHELL FINITE-ELEMENT ANALYSIS
Desbrun, Mathieu
SUBDIVISION SURFACES: A NEW PARADIGM FOR THIN-SHELL FINITE-ELEMENT ANALYSIS Fehmi Cirak1 , Michael for thin-shell finite-element analysis based on the use of subdivision surfaces for: i) describing by subdivision are H2 and, consequently, have a finite Kirchhoff-Love energy. The resulting finite elements
Method for detecting an element
Blackwood, Larry G.; Reber, Edward L.; Rohde, Kenneth W.
2007-02-06
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.
An Annotated Reference Guide to the Finite-Element Interface Specification Version 1.0
Alan B. Williams; Ivan J. Otero; Kyran D. Mish; Lee M. Tayor; Robert L. Clay
1999-04-01
The Finite-Element Interface (FEI) specification provides a layered abstraction that permits finite-element analysis codes to utilize various linear-algebra solution packages with minimal concern for the internal details of the solver modules. Alternatively, this interface can be viewed as a way for solver developers to provide solution services to finite-element clients without having to embed finite-element abstractions within their solver libraries. The purpose of this document is to provide some level of documentation between the bare interface specification itself, which consists only of C/C++ header files, and the full documentation suite that supports the interface definition by providing considerable detail as to its design and implementation. This document primarily provides the ''how'' of calling the interface member functions, so that programmers can readily learn how to utilize the interface implementation without having to consider all the details contained in the interface's definition, design, and motivation. The interface specification is presented three times in this document, each time with an increasing level of detail. The first presentation provides a general overview of the calling sequence, in order to acquaint the programmer with a basic introduction to how the interface is used to ''train'' the underlying solver software on the particular finite-element problem that is to be solved. The second pass through the interface definition provides considerable detail on each method, including specific considerations as to the structure of the underlying data, and an exposition of potential pitfalls that may occur as a byproduct of either the finite-element modeling process, or of the use of the associated interface implementation. Finally, a third description of the interface is given implicitly via the discussion of sample problems that provide concrete examples of the use of the finite-element interface.
On Smoothing Surfaces in Voxel Based Finite Element Analysis of Trabecular Bone
Frey, Pascal
On Smoothing Surfaces in Voxel Based Finite Element Analysis of Trabecular Bone Peter Arbenz on complicated domains composed of often hundreds of millions of voxel elements. The finite element analysis finite element (FE) analysis. The approach based on the FE analysis leads to linear systems of equations
Finite element modeling of SHTE and PSVTM electroseismics
Fabio I. Zyserman
2010-10-07
element method to model electric fields induced by acoustic waves in ...... homogeneous layer of water-saturated poorly permeable shale; the .... As in gas/
James, Stephen M.
2011-08-08
? Matrix of eigenvectors of rotor [ ]rA ? Component mode synthesis transformation matrix for rotor [ ]XA ? Eigenvector matrix for X Z? plane [ ]YA ? Eigenvector matrix for Y Z? plane , , , b1 b2 b3 b4 ? Bearings used in component... [F] FEA ? Finite element analysis FEM ? Finite element methods ; 1:if i = m ? ith force matrix element in Guyan reduction [F] { }rBF ? Transformed rotor external forces matrix ; 1:rif i m= ? Force acting at the ith station of rotor...
Evaluation of an existing bridge`s modal properties using simplified finite element analysis
Farrar, C.R.; Duffey, T.A.
1996-02-01
The purpose of this paper is to present results of a simplified approach to the dynamic finite element modeling of composite girder-slab bridges using a single beam element to represent the girder-slab cross section. Dynamic properties calculated with these simplified models are compared to experimental results and results obtained from more detailed shell element models. The method for modeling flexural behavior is first discussed followed by a discussion of modeling torsional behavior. The beam element models accurately calculated the mode shapes of the structure, but the associated resonant frequencies showed some error.
Calibration under uncertainty for finite element models of masonry monuments
Atamturktur, Sezer,; Hemez, Francois,; Unal, Cetin
2010-02-01
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.
Finite Element Modeling of Micromachined MEMS Photon Devices
Datskos, P.G.; Evans, B.M.; Schonberger, D.
1999-09-20
The technology of microelectronics that has evolved over the past half century is one of great power and sophistication and can now be extended to many applications (MEMS and MOEMS) other than electronics. An interesting application of MEMS quantum devices is the detection of electromagnetic radiation. The operation principle of MEMS quantum devices is based on the photoinduced stress in semiconductors, and the photon detection results from the measurement of the photoinduced bending. These devices can be described as micromechanical photon detectors. In this work, we have developed a technique for simulating electronic stresses using finite element analysis. We have used our technique to model the response of micromechanical photon devices to external stimuli and compared these results with experimental data. Material properties, geometry, and bimaterial design play an important role in the performance of micromechanical photon detectors. We have modeled these effects using finite element analysis and included the effects of bimaterial thickness coating, effective length of the device, width, and thickness.
Surface Based Atlas Matching of the Brain Using Deformable Surfaces and Volumetric Finite Elements
Surface Based Atlas Matching of the Brain Using Deformable Surfaces and Volumetric Finite Elements onto the target image and interpolate the surface displacement to obtain a fully volumetric mapping (e.g. [3]). Volumetric methods compute a deformation field that minimizes a similarity criterion between
3-D Finite Element Analyses of the Egan Cavern Field
Klamerus, E.W.; Ehgartner, B.L.
1999-02-01
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.
An evaluation of finite element models of stiffened plates subjected to impulsive loading
Pedatzur, Omri
2004-01-01
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 ...
Implementation of finite element analysis into the athletic shoe design process
Hidalgo, Maria E. (Maria Estela), 1982-
2004-01-01
Finite element analysis is used by companies throughout the world as a substitution for manually testing prototypes. With the assistance of finite element analysis many companies and industries have decreased the time and ...
Giurgiutiu, Victor
Finite Element Simulation of Piezoelectric Wafer Active Sensors for Structural Health Monitoring) is emerging as an effective and powerful technique in structural health monitoring (SHM). Modeling to analytical calculation and experimental data. Key words: Structural Health Monitoring, PWAS, finite element
Implementation of B-splines in a Conventional Finite Element Framework
Owens, Brian C.
2010-01-16
that describe the process of implementing B-splines into an existing finite element framework. Therefore, it is necessary to document this methodology. This implementation should conform to the structure of conventional finite elements and only require...
Finite element analyses for seismic shear wall international standard problem
Park, Y.J.; Hofmayer, C.H.
1998-04-01
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.
Element-based concrete design with three-dimensional finite element models
O'Leary, M.; Huberty, K.; Winch, S. [Nuclear Power Technologies Div., Sargent and Lundy, 55 East Monroe, Chicago, IL 60603 (United States)
2012-07-01
A shell element based design of a typical shear wall using analytical results from a three-dimensional finite element model subjected to a combination of vertical and lateral loads is evaluated. The axial and flexural force resultants from each element for every load combination are used to calculate the required reinforcing for each element. Strength for axial loads (P) and out-of-plane flexure (M) in structural walls is determined according to the same P-M interaction procedures used for columns. After each element has been evaluated, a required reinforcing map for each face of each element in the wall is presented along with a constructible reinforcement pattern enveloping the required reinforcing. In order to determine whether the element-based approach meets the requirements of the section cut approach to design, which is typically employed in manual calculations, the total in-plane moment (M) and total vertical axial force (P) across the entire length of the wall is calculated and the P-M points are plotted on an in-plane P-M interaction diagram. It is concluded that element-based design for a structural wall ensures that reinforcement is provided where required by the three-dimensional finite element analysis while still providing sufficient reinforcing to satisfy the section cut approach to design. (authors)
Barham, M; White, D; Steigmann, D; Rudd, R
2009-04-08
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.
Wear 258 (2005) 17871793 Finite element analysis and experiments of metal/metal
Sawyer, Wallace
2005-01-01
Wear 258 (2005) 17871793 Finite element analysis and experiments of metal/metal wear-on-disk experiments. The results from the finite element analysis were in close agreement with the block of this simulation. © 2004 Published by Elsevier B.V. Keywords: Wear modeling; Finite element analysis 1
Wrinkle development analysis in thin sail-like structures using MITC shell finite elements
Paris-Sud XI, Université de
Wrinkle development analysis in thin sail-like structures using MITC shell finite elements D submitted to Finite Elements in Analysis and Design September 20, 2012 hal-00733994,version1-20Sep2012 Author manuscript, published in "Finite Elements in Analysis and Design 64 (2013) 48-64" DOI : 10.1016/j
Tolerance Analysis of Flexible Assemblies Using Finite Element and Spectral Analysis
Tolerance Analysis of Flexible Assemblies Using Finite Element and Spectral Analysis ADCATS Report the autocorrelation function from frequency spectrum analysis to model random surface variations. Finite element BACKGROUND LITERATURE REVIEW 5 3 STATISTICAL TOLERANCE ANALYSIS USING FINITE ELEMENT ANALYSIS 3.1 Assumptions
Finite element analysis of performance in the skulls of marmosets and tamarins
Dumont, Elizabeth R.
Finite element analysis of performance in the skulls of marmosets and tamarins Elizabeth R. Dumont compara- tive analyses. Key words finite element analysis; marmoset; performance; tamarin. Introduction. Using 3D finite element models of the marmoset Callithrix jacchus and the tamarin Saguinus fuscicollis
Approximation Theory and Finite Element Analysis January 2014 Lecturer David Silvester
Silvester, David J.
Approximation Theory and Finite Element Analysis January 2014 Lecturer David Silvester Office Alan Analysis, CUP, 2003. · Dietrich Braess, Finite Elements: Theory, Fast Solvers and Applications in Solid Mechanics, CUP, Third Edition, 2007. · Howard Elman, David Silvester and Andy Wathen, Finite Elements
Free Body Analysis, Beam Mechanics, and Finite Element Modeling of the Mandible of Alligator
Free Body Analysis, Beam Mechanics, and Finite Element Modeling of the Mandible of Alligator arm mechanics, 2D and 3D beam mod- els, and three high-resolution finite element models- pared with the beam models, the Alligator finite element models exhibited less spatial variability
The Finite Element Analysis of Quartz Crystal Resonators with Nonlinear Plate Equations
Wang, Ji
The Finite Element Analysis of Quartz Crystal Resonators with Nonlinear Plate Equations Ji Wang1, dujianke, wanglihong}@nbu.edu.cn, yyong@rci.rutgers.edu Abstract--The finite element analysis of quartz for typical thickness-shear vibrations of quartz crystal plates. While linear finite element analysis
Finite Element Analysis of Nonlinear Thickness-shear Vibrations of AT-cut Quartz Crystal Plates
Wang, Ji
Finite Element Analysis of Nonlinear Thickness-shear Vibrations of AT-cut Quartz Crystal Plates Ji, dujianke}@nbu.edu.cn Abstract--The nonlinear finite element analysis is performed with the nonlinear a smaller size in comparison with the 3D approach. General procedure of nonlinear finite element analysis
FINITE ELEMENT ANALYSIS OF A CLASS OF STRESS-FREE MARTENSITIC MICROSTRUCTURES
Li, Bo
FINITE ELEMENT ANALYSIS OF A CLASS OF STRESS-FREE MARTENSITIC MICROSTRUCTURES BO LI Abstract. This work is concerned with the finite element approximation of a class of stress-free martensitic microstructures modeled by multi-well en- ergy minimization. Finite element energy-minimizing sequences are first
ANL/APS/TB-19 A Finite Element Analysis of Room Temperature Silicon Crystals
Kemner, Ken
ANL/APS/TB-19 A Finite Element Analysis of Room Temperature Silicon Crystals for the Advanced #12;ANL/APS/TB-19 1 A Finite Element Analysis of Room Temperature Silicon Crystals for the Advanced if the monochromator is not properly designed (or cooled). This document describes a series of finite element analyses
Comparison of Beam Theory and Finite-Element Analysis With In Vivo
Comparison of Beam Theory and Finite-Element Analysis With In Vivo Bone Strain Data From structures and, more recently, finite- element (FE) analysis. In this study, we compare experimentally-Liss, Inc. Key words: bone strain; finite-element analysis; skull biome- chanics; alligator; feeding
Finite Elements in Analysis and Design 41 (2004) 253265 www.elsevier.com/locate/finel
Rivero, Jose Pablo SuÃ¡rez
2004-01-01
Finite Elements in Analysis and Design 41 (2004) 253Â265 www.elsevier.com/locate/finel The 8 favorable in finite element analysis. Furthermore, since a right prism can be subdivided into six right adaptive finite element analysis procedure has received much attention
Miga, Michael I.
A finite element inverse analysis to assess functional improvement during the fracture healing architecture on the FEA estimated material property metric. The finite element model inverse analysis developed i n f o Article history: Accepted 2 September 2009 Keywords: Fracture healing Finite element
A Finite Element Analysis of Masticatory Stress Janine Chalk,1,2
A Finite Element Analysis of Masticatory Stress Hypotheses Janine Chalk,1,2 * Brian G. Richmond,2). This study uses finite element analysis to examine the extent to which these geometric models provide loading regimes, were applied to a previously validated finite element model (FEM) of a macaque (Macaca
Finite Element Analysis of Ultrasonic Processing of a Polymer-Matrix Composite
Roylance, David
Finite Element Analysis of Ultrasonic Processing of a Polymer- Matrix Composite Wenguang Zhao1 parameters, makes trial-and-error analysis of the process difficult, and this paper demonstrates how a finite-element; Ultrasonic Tape Lamination; Viscoelastic dissipation; Finite-element analysis 1. Introduction This paper
Vecchio, Frank J.
Abstract ii NONLINEAR FINITE ELEMENT ANALYSIS OF REINFORCED CONCRETE STRUCTURES SUBJECTED nonlinear finite element transient thermal analysis is implemented into program VecTor2©, a nonlinear's response to thermal loads, this research develops and implements a 2D nonlinear finite element transient
Author's personal copy The effects of modeling simplifications on craniofacial finite element models
a r t i c l e i n f o Article history: Accepted 17 March 2011 Keywords: Finite element analysis Tooth), a biomechanical system commonly studied using finite element analysis (FEA) is that part of the craniofacial in such finite element models (FEMs) depends exten- sively on the objective of the analysis and the performance
Chen, Zheng
-F, July 725, 2014; Final Exam: 1-4 PM, July 26, 2014 Objective To develop an understanding of finite. References 1. D. L. Logan, The First Course in the Finite Element Method, 5th Edition, SI; Cengage Learning Project Assessment (20%) 30% Midterm Exam 10% Final Exam 40% Total 100% #12;
Guaranteed Verification of Finite Element Solutions of Heat Conduction
Wang, Delin
2012-07-16
||uSp?h ||C, and the relative value of C-norm of the error ||eh||C / ||u||C, for the semi-discrete solutions of degree p = 1, 2 and 3, computed using uniform meshes with mesh size h = L2n , n = 1, 2, 3, and 4 respectively.... . . . . . . . . . . . . . . . . . 67 4.2 Heat transition problem in one dimension. The effectivity indices ? based on the exact solution u? and ?Sp+k?h? = ESp+k?h? /||eh||C based on the finite element solution u?Sp+k?h? (k = 1, 2, 3, and ?h? from the nest subdivision...
Conditioning of finite element equations with arbitrary anisotropic meshes
Kamenski, Lennard; Huang, Weizhang; Xu, Hongguo
2014-03-05
OF COMPUTATION Volume 83, Number 289, September 2014, Pages 2187–2211 S 0025-5718(2014)02822-6 Article electronically published on March 5, 2014 CONDITIONING OF FINITE ELEMENT EQUATIONS WITH ARBITRARY ANISOTROPIC MESHES LENNARD KAMENSKI, WEIZHANG HUANG... scaling. This work was supported in part by the DFG (Germany) under grants KA 3215/1-1 and KA 3215/2-1 and the National Science Foundation (U.S.A.) under grants DMS-0712935 and DMS- 1115118. c©2014 American Mathematical Society Reverts to public domain 28...
Generalized finite element method for multiscale analysis
Zhang, Lin
2004-11-15
solutions ||uh||U and the overkill solutions ||uov||U. Analytical void functions of order pvoid = 1 were employed for the simple handbook solutions psiX;1/2j . ..................... 30 3.2 Relative errors eGFEMREL (deltah,p,phb; gamma) for Problems I...GFEMREL (deltah,p,phb; gamma) for Problem I(a)-I(d). The approx- imate solutions were computed by employing the handbook functions psiX;1/2j , but no analytical void functions were used in the numerical con- struction of these functions...
A NONCONFORMING MIXED FINITE ELEMENT METHOD FOR ...
1910-10-30
Their natural sources are electric storms and solar wind fluctuations that generate electromagnetic waves in the ionosphere. These waves arrive at the earth's.
CONVERGENCE OF A MULTISCALE FINITE ELEMENT METHOD ...
1999-04-17
Mar 3, 1999 ... In the above proof, ul is used as an intermediate step towards ...... Current address: Exxon Production Research Company, P. O. Box 2189, Houston, TX 77252 ... Department of Mathematics, Purdue University, West Lafayette, ...
AN ADAPTIVE FINITE ELEMENT METHOD FOR THE ...
2015-06-30
Confinement Fusion Science Program under grant 2011GB105003 and by .... to be nonmagnetic, and E and H denote the electric field and the magnetic field in.
Cambridge, University of
Element Analysis, H. K. D. H. Bhadeshia Lecture 2: Finite Elements In finite element analysis, functions to be homogeneous. In finite element stress analysis, the elastic body is first divided into discrete connected. Thus, a finite element representation of a circle would be a circumscribed polygon, with each edge
A Finite Element Model for Simulation of Carbon Dioxide Sequestration
Bao, Jie; Xu, Zhijie; Fang, Yilin
2013-11-02
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.
Beaumont, Christopher
1 Salt tectonics driven by differential sediment loading: Stability analysis and finite element of the basin. We use 2-D finite element modelling to investigate systems in which a linear viscous salt layer is used to investigate the subsequent finite deformation. As the systems evolve, overburden extension
Finite element analyses of a linear-accelerator electron gun
Iqbal, M. E-mail: muniqbal@ihep.ac.cn; Wasy, A.; Islam, G. U.; Zhou, Z.
2014-02-15
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.
FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE
Jordan, J.
2010-06-02
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.
ANALYSIS OF MIXED FINITE ELEMENTS FOR LAMINATED COMPOSITE PLATES
Lovadina, Carlo
an extension-bending coupling (i.e. in-plane displacements arise even for vertical loads). The paper- dard membrane element for the in-plane displacements with a robust method for plate bending problem direction; Â· they exhibit extension-bending coupling. In literature, many different models have been
Finite Element Modelling Of Thermal Processes With Phase Transitions
Vuik, Kees
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 1D steady diffusion equation . . . . . . . . . . . . . . . . . . . . . 5 2.2.1 Weak matrix and vector . . . . . . . . . . 8 2.2.5 Boundary conditions and assembly . . . . . . . . . . . . . . . . . . . . . . . 14 2.3.5 Streamline Upwind Petrov Galerkin method . . . . . . . . 16 2.4 Linear elements in two
Cambridge, University of
Element Analysis, H. K. D. H. Bhadeshia Lecture 3: Finite Elements Steadystate heat flow through A and length L. The finite element representation consists of two nodes i and j. Heat flow in one. The temperatures T1 and T2 are maintained constant. The finite element representation consists of a single element
Electrogalvanic finite element analysis of partially protected marine structures
Kasper, R.G.; April, M.G.
1983-05-01
A general finite element modeling (FEM) procedure for calculating electrogalvanic field responses due to multiple anodic/cathodic interactions has been developed. Within any defined electrolytic continuum the exact geometry and location of anodes, cathodes, and paint surfaces can now be realistically incorporated in the mathematical model formulation. The anodic/cathodic interactions in the conductive electrolyte are predicted by the application of classical d.c. electric field theory for conductive continuums in conjunction with widely accepted laboratory oxidation/reduction responses for the electrodes. The electrogalvanic fields in the electrolyte are calculated using the scalar Poisson equation whereby traditional boundary conditions are prescribed in the far field of the electrolyte. In the near field of the anodes, cathodes, and the painted metallic substrate, complex boundary conditions are enforced based on empirical polarization curves and paint impedance values. The ionic current in the electrolyte leaving the anode and arriving at the cathodes are mathematically constrained to sum to zero over the metallic surface (spatial Kirchoff's law). Three example problems (three dimensional) of an iron bar in salt water will demonstrate the electrochemical field effects due to relative anodic/cathodic spacing, anodic/cathodic geometries, and infinite paint impedance. A fourth boundary value problem (two dimensional) will illustrate the effect of a paint discontinuity (unprotected area) in the center of the otherwise painted (finite impedance) metallic substrate. The proposed electrochemical modeling procedure has the advantage of concurrently treating numerous essential electrochemical parameters for any geometric anodic/cathodic configurations consistent with the physical laws of electrochemistry.
SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics
Laursen, T.A.; Attaway, S.W.; Zadoks, R.I.
1999-03-01
This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples of the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.
Integrated Modeling, Finite-Element Analysis, and Engineering Design for Thin-Shell
Schroeder, Peter
Integrated Modeling, Finite-Element Analysis, and Engineering Design for Thin-Shell Structures transfer between the geometric design and finite-element anal- ysis tools. No cumbersome remodeling.S.A. Abstract Many engineering design applications require geometric modeling and mechanical simulation of thin
TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities
TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F. Marhauser BESSY GmbH #12;TESLA FEL Report 200602 Contents 1. INTRODUCTION......................................................................................................................................................28 #12;TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F
Prediction of a Mysticete Audiogram via Finite Element Analysis of the Middle Ear
Prediction of a Mysticete Audiogram via Finite Element Analysis of the Middle Ear Andrew Tubelli (Rosowski 1994). Biophysical models of the cetacean middle ear can be developed using finite element (FE for FE analysis (COMSOL, Stockholm, Sweden). _________________________ A. Tubelli (!) · A. Zosuls · D
STATISTICAL AND 3D NONLINEAR FINITE ELEMENT ANALYSIS OF SCHLEGEIS DAM
Balaji, Rajagopalan
STATISTICAL AND 3D NONLINEAR FINITE ELEMENT ANALYSIS OF SCHLEGEIS DAM VICTOR SAOUMA, ERIC HANSEN is composed of two parts. First a statistical analysis of the dam crest displacement is performed, along with a prediction for the years 2000-2001. Then a 3D finite element analysis of Schlegeis dam is performed using
Finite-Element Investigation and Design Recommendations for Perforated Steel Plate Shear Walls
Bruneau, Michel
Finite-Element Investigation and Design Recommendations for Perforated Steel Plate Shear Walls.k.a. perforated SPSW . Finite element monotonic pushover analyses were conducted, first on a series of individual perforated strips with variation in perforation diameter, to develop a fundamental understanding
FINITE ELEMENT INVESTIGATION AND DESIGN RECOMMENDATIONS FOR PERFORATED STEEL PLATE SHEAR WALLS
Bruneau, Michel
FINITE ELEMENT INVESTIGATION AND DESIGN RECOMMENDATIONS FOR PERFORATED STEEL PLATE SHEAR WALLS of the behavior of unstiffened thin SPSW having a regular pattern of openings (a.k.a. perforated SPSW). Finite element monotonic pushover analyses were conducted, first on a series of individual perforated strips
thickness using finite-element analysis David S. Strait a,*, Brian G. Richmond b , Mark A. Spencer c which early hominid features are functionally related to chewing. This paper uses finite-element Paranthropus synapomorphies putatively related to mastication. A finite-element model of 145,680 elements
Low frequency eddy current finite element model validation and benchmark studies
Cherry, M.; Knopp, J. [Materials and Manufacturing Directorate, Air Force Research Laboratory (United States); Mooers, R.; Boehnlein, T. [University of Dayton Research Institute, Dayton, OH (United States); Aldrin, J. C. [Computational Tools, Gurnee, IL (United States); Sabbagh, H. A. [Victor Technologies, LLC, Bloomington, IN (United States)
2011-06-23
A finite element method (FEM) model was created to calculate the change in impedance of a coil due to the presence of a notch in a plate. The rectangular notches were created via electrical discharge machining (EDM) in a thick aluminum plate and were positioned at normal and oblique angles (10, 20, and 30 degrees) with respect to the vertical axis of the coil. The FEM method was chosen for this model due to its ability to solve problems in complicated geometries with the use of irregular mesh elements to discretize the solution domain. The change in impedance was calculated from the field variables in the simulation for each probe position along the parallel axis of the plate. The error between the model and the experimental data was approximately 5% for the majority of cases. The validated model was used to investigate more complex problems.
Analysis of delamination growth with discontinuous finite elements
Remmers, Joris J C; Wells, G N; De Borst, R
of the incorporated interface elements is examined by means of a three point bending test. Conventional interface elements suffer from spurious stress oscillations for high ratios of dummy stiffnesses and the Young’s modulus of the continuum elements [2... than conventional interface elements, especially when geometrically nonlinearities are incorporated. Furthermore, the ele- ments can still be used in unstructured meshes. In the remainder of this paper, we will refer to this element type...
Method of lightening radiation darkened optical elements
Reich, Frederich R. (Richland, WA); Schwankoff, Albert R. (W. Richland, WA)
1980-01-01
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.
Multigrid for Higher Order Discontinuous Galerkin Finite Elements Applied to Groundwater Flow
Bastian, Peter
Multigrid for Higher Order Discontinuous Galerkin Finite Elements Applied to Groundwater Flow Peter elements applied to the groundwater flow equation. It uses an incomplete LU decomposition on an element for diffusion problems has been formu- lated in [6]. 1.1 Notation In this paper we wish to solve the groundwater
Mimetic finite difference method for the stokes problem on polygonal meshes
Lipnikov, K; Beirao Da Veiga, L; Gyrya, V; Manzini, G
2009-01-01
Various approaches to extend the finite element methods to non-traditional elements (pyramids, polyhedra, etc.) have been developed over the last decade. Building of basis functions for such elements is a challenging task and may require extensive geometry analysis. The mimetic finite difference (MFD) method has many similarities with low-order finite element methods. Both methods try to preserve fundamental properties of physical and mathematical models. The essential difference is that the MFD method uses only the surface representation of discrete unknowns to build stiffness and mass matrices. Since no extension inside the mesh element is required, practical implementation of the MFD method is simple for polygonal meshes that may include degenerate and non-convex elements. In this article, we develop a MFD method for the Stokes problem on arbitrary polygonal meshes. The method is constructed for tensor coefficients, which will allow to apply it to the linear elasticity problem. The numerical experiments show the second-order convergence for the velocity variable and the first-order for the pressure.
McCready, Mark J.
Version: 6/16/98 Keywords: wavy surface flow, finite element, longwave analysis, weakly and drag are found, from finite element calculations, to increase as amplitude to approximately the third wavelength problem is solved numerically with a finite element formulation providing qualitative trends
Miga, Michael I.
A Novel Inverse Finite Element Analysis to Assess Bone Fracture Healing in Mice Receiving Bone generation, and an iterative optimization (using finite element analysis) of the fracture callus material approach includes acquisition of microCT image volumes, biomechanical testing, finite element mesh
John, Volker
48 2 Functional Analysis for Linear Saddle Point Problems 2.4 Examples of Pairs of Finite Element Spaces Violating the Discrete Inf-Sup Condition Remark 2.50. On simple pairs of finite element spaces. The simplest and most common finite element spaces are spaces of continuous functions which are piecewise
Collins, Gary S.
Finite Element Analysis of Spherical Indentation Tests John Homans1, Sinisa Dj. Mesarovic2, Harish finite element analysis program Abaqus 6.7. · Runs were repeated using a dense mesh to ensure accuracy not influence the solution. Objective · Develop a finite element model to analyze: i) Load-depth response
Spectral analysis method for detecting an element
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
2008-02-12
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.
Evaluation of the matrix exponential function using finite elements in time
Gebremedhin, D H; Zhang, X; Wynn, A; Tanaka, G
2008-01-01
The evaluation of a matrix exponential function is a classic problem of computational linear algebra. Many different methods have been employed for its numerical evaluation [Moler C and van Loan C 1978 SIAM Review 20 4], none of which produce a definitive algorithm which is broadly applicable and sufficiently accurate, as well as being reasonably fast. Herein, we employ a method which evaulates a matrix exponential as the solution to a first-order initial value problem in a fictitious time variable. The new aspect of the present implementation of this method is to use finite elements in the fictitious time variable. [Weatherford C A, Red E, and Wynn A 2002 Journal of Molecular Structure 592 47] Then using an expansion in a properly chosen time basis, we are able to make accurate calculations of the exponential of any given matrix as the solution to a set of simultaneous equations.
Evaluation of the matrix exponential function using finite elements in time
D H Gebremedhin; C A Weatherford; X Zhang; A Wynn III; G Tanaka
2008-11-17
The evaluation of a matrix exponential function is a classic problem of computational linear algebra. Many different methods have been employed for its numerical evaluation [Moler C and van Loan C 1978 SIAM Review 20 4], none of which produce a definitive algorithm which is broadly applicable and sufficiently accurate, as well as being reasonably fast. Herein, we employ a method which evaulates a matrix exponential as the solution to a first-order initial value problem in a fictitious time variable. The new aspect of the present implementation of this method is to use finite elements in the fictitious time variable. [Weatherford C A, Red E, and Wynn A 2002 Journal of Molecular Structure 592 47] Then using an expansion in a properly chosen time basis, we are able to make accurate calculations of the exponential of any given matrix as the solution to a set of simultaneous equations.
On a tensor-based finite element model for the analysis of shell structures
Arciniega Aleman, Roman Augusto
2006-04-12
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 ...
Qapo, Michael; Dirar, Samir; Yang, Jian; Elshafie, Mohammed Z. E. B.
2014-12-16
This paper presents a three-dimensional nonlinear finite element (FE) model for prestressed concrete girders strengthened in shear with externally bonded carbon fibre reinforced polymer (CFRP) reinforcement. A total strain rotating crack model...
Miniature Hourglass Shaped Actuator Geometry Study Using A Finite Element Simulation
Elwell, Roston Clement
2011-08-08
This project investigated a miniature, hourglass-shaped actuator (MHA) and how its geometry affects performance. A custom, self-contained, finite-element simulation code predicts how each MHA deforms when pressurized ...
Bangerth, Wolfgang
Experimental Fluorescence Optical Tomography using Adaptive Finite Elements and Planar Illumination with Modulated Excitation Light Amit Joshia , Wolfgang Bangerthb , Alan B. Thompsona , and Eva M. Sevick adaptive discretization strategies. To date, the efficacy of adaptive mesh refinement techniques has yet
Least squares based finite element formulations and their applications in fluid mechanics
Prabhakar, Vivek
2009-05-15
In this research, least-squares based finite element formulations and their applications in fluid mechanics are presented. Least-squares formulations offer several computational and theoretical advantages for Newtonian as well as non-Newtonian fluid...
A Finite Element-Multibody Dynamics Co-simulation Methodology Applied to FAST
Suryakumar, Vishvas Samuel
2013-05-02
A co-simulation methodology is explored whereby a finite element code and a multi-body dynamics code featuring flexible cantilevered beams can be coupled and interactively executed. The floating frame of reference formulation is used to develop...
Finite element analysis of elastic interaction of two en echelon overlapping faults
Leem, Junghun
1995-01-01
on the faults. Attention is focuses on the role of variable fault spacing and overlap for constant far-field compressive principal stresses. The linear elastic, isotropic, plane strain, finite element analyses are obtained. The basic modeling approach...
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES
Bartels, Soeren
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES Geometric partial differential equations and their analysis as well as numerical simulation have recently
TEA - a linear frequency domain finite element model for tidal embayment analysis
Westerink, Joannes J.
1984-01-01
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 ...
Jackson, Jason R.
1996-01-01
Elastomers are becoming more prevalent in everyday products, and it is very important to be able to describe their behavior. Particularly, with advancements in computer hardware and software, the use of finite element ...
JOURNAL OF MATERIALS SCIENCE 38 (2003) 307 322 Crystal plasticity-based finite element analysis
Grujicic, Mica
2003-01-01
JOURNAL OF MATERIALS SCIENCE 38 (2003) 307 322 Crystal plasticity-based finite element analysis-dependent, finite-strain, crystal-plasticity based materials constitutive model is used to represent the deformation obtained show that plastic flow localizes into deformation bands even at an overall strain level of only 0
Finite element analysis of conjugate heat transfer in axisymmetric pipe flows
Fithen, Robert Miller
1987-01-01
FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MA STER... OF S CI EN CE August 1987 Major Subject: Mechanical Engineering FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Approved ss to style and content by: N. K. Anand (Chairman of Committee...
A finite element analysis of shrinkage stress fields in two-phase materials
Hall, Frank
1980-01-01
A FINITE ELEMENT ANALYSIS OF SHRINKAGE STRESS FIELDS IN TWO-PHASE MATERIALS A Thesis by FRANK HALL Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1980 Maj or Subj ect: Mechanical Engineering A FINITE ELEMENT ANALYSIS OF SHRINKAGE STRESS FIELDS IN TWO-PHASE MATERIALS A Thesis FRANK HALL Approved as to style and content by: (Chairman of Committee) (Member) (Member) (Member) (H d...
Structural Mechanics & Solid Mechanics A finite element toolbox to MATLAB
Ehrhardt, Matthias
Structural Mechanics & Solid Mechanics Department of Mechanics and Materials CALFEM A finite.3 Copyright Â© 1999 by Structural Mechanics, LTH, Sweden. Printed by JABE Offset, Lund, Sweden. ISRN LUTVDG/TVSM--99/9001--SE (1-265) ISSN 0281-6679 Department of Mechanics and Materials Structural Mechanics #12;The
David L. Meier
1998-11-10
A new field of numerical astrophysics is introduced which addresses the solution of large, multidimensional structural or slowly-evolving problems (rotating stars, interacting binaries, thick advective accretion disks, four dimensional spacetimes, etc.). The technique employed is the Finite Element Method (FEM), commonly used to solve engineering structural problems. The approach developed herein has the following key features: 1. The computational mesh can extend into the time dimension, as well as space, perhaps only a few cells, or throughout spacetime. 2. Virtually all equations describing the astrophysics of continuous media, including the field equations, can be written in a compact form similar to that routinely solved by most engineering finite element codes. 3. The transformations that occur naturally in the four-dimensional FEM possess both coordinate and boost features, such that (a) although the computational mesh may have a complex, non-analytic, curvilinear structure, the physical equations still can be written in a simple coordinate system independent of the mesh geometry. (b) if the mesh has a complex flow velocity with respect to coordinate space, the transformations will form the proper arbitrary Lagrangian- Eulerian advective derivatives automatically. 4. The complex difference equations on the arbitrary curvilinear grid are generated automatically from encoded differential equations. This first paper concentrates on developing a robust and widely-applicable set of techniques using the nonlinear FEM and presents some examples.
3-D Finite-Element Modelling of Magnetotelluric Data With a Static Divergence Correction
Farquharson, Colin G.
correction #12;Standard Finite-Element Modelling: Results 1e-14 1e-131e-13 1e-12 1e-11 1e-10 1e-09 1e-08 1e.1 Hz, without correction #12;Standard Finite-Element Modelling: Results 1e-14 1e-131e-13 1e-12 1e-11 1e-Element Modelling With Correction: Results 1e-14 1e-131e-13 1e-12 1e-11 1e-10 1e-09 1e-08 1e-07 1e-06 1e-05 0.0001 0
Torres-Verdín, Carlos
hp-Adaptive Multiphysics Finite Element Simulation of LWD Borehole Sonic Waveforms Pawel J-physics, finite-element method to simulate LWD borehole acoustic waveforms in the presence of the tool. The method truncation of the spatial domain. Examples of appli- cation are shown for the simulation of LWD sonic
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansasCommunitiesofExtrans - Permeation Measurement2TargetedFEHM (Finite
Wang, Ji; Sun, Qiang; Wu, Rongxing; Huang, Bin; Du, Jianke; Xiang, Wei
2015-01-01
The finite element analysis of high frequency vibrations of quartz crystal plates is a necessary process required in the design of quartz crystal resonators of precision types for applications in filters and sensors. The anisotropic materials and extremely high frequency in radiofrequency range of resonators determine that vibration frequency spectra are complicated with strong couplings of large number of different vibration modes representing deformations which do not appear in usual structural problems. For instance, the higher-order thickness-shear vibrations usually representing the sharp deformation of thin plates in the thickness direction, expecting the analysis is to be done with refined meshing schemes along the relatively small thickness and consequently the large plane area. To be able to represent the precise vibration mode shapes, a very large number of elements are needed in the finite element analysis with either the three-dimensional theory or the higher-order plate theory, although considera...
Krabicka, J.; Yan, Y.
2009-08-15
Electrostatic sensors are used in certain industries for the flow measurement of pneumatically conveyed solids. However, despite various advances that have been made in recent years, relatively little information is known about the exact nature of the electrostatic charge induced onto the sensor electrode due to moving particles, which is dependent on electrode geometry, particle distribution, and particle velocity. This paper presents a novel approach to the study of the charge induced onto electrostatic sensors based on fitting a Lorentzian curve to the results of a finite-element model of the electrostatic sensor and pipeline. The modeling method is validated by comparing the modeling results of a nonintrusive circular electrode with an established analytical solution. The modeling results are used for in-depth analysis and informed design of a particular sensor configuration.
Numerical computation of constant mean curvature surfaces using finite elements
Jan Metzger
2004-08-18
This paper presents a method for computing two-dimensional constant mean curvature surfaces. The method in question uses the variational aspect of the problem to implement an efficient algorithm. In principle it is a flow like method in that it is linked to the gradient flow for the area functional, which gives reliable convergence properties. In the background a preconditioned conjugate gradient method works, that gives the speed of a direct elliptic multigrid method.
The strong Bass conjecture for group elements of finite order and for residually finite groups
Schick, Thomas
groups Thomas Schick* Last compiled October 5, 2000; last edited Oct 5~g __________________________* e-mail: thomas.schick@math.uni-muenster.de www: http://wwwmath.uni-muenster.de/u/lueck/schick Thomas Schick If P is a finitely generated projective kG-module, choose a "complement" Q such that P
century as in the 19th century. In this paper I use finite element analysis to address the question, how element analysis Tom Parsons U.S. Geological Survey, Menlo Park, California, USA Received 23 August 2001 area seismic hazard assessment. This study presents a three-dimensional (3-D) finite element simulation
Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur
Ascenzi, Maria-Grazia, E-mail: mgascenzi@mednet.ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States)] [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Kawas, Neal P., E-mail: nealkawas@ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Lutz, Andre, E-mail: andre.lutz@hotmail.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany)] [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Kardas, Dieter, E-mail: kardas@ibnm.uni-hannover.de [ContiTech Vibration Control, Jaedekamp 30 None, 30419 Hannover (Germany)] [ContiTech Vibration Control, Jaedekamp 30 None, 30419 Hannover (Germany); Nackenhorst, Udo, E-mail: nackenhorst@ibnm.uni-hannover.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany)] [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Keyak, Joyce H., E-mail: jhkeyak@uci.edu [Department of Radiological Sciences, Medical Sciences I, Bldg 811, Room B140, University of California, Irvine, CA 92697-5000 (United States)
2013-07-01
We present an innovative method to perform multi-scale finite element analyses of the cortical component of the femur using the individual’s (1) computed tomography scan; and (2) a bone specimen obtained in conjunction with orthopedic surgery. The method enables study of micro-structural characteristics regulating strains and stresses under physiological loading conditions. The analysis of the micro-structural scenarios that cause variation of strain and stress is the first step in understanding the elevated strains and stresses in bone tissue, which are indicative of higher likelihood of micro-crack formation in bone, implicated in consequent remodeling or macroscopic bone fracture. Evidence that micro-structure varies with clinical history and contributes in significant, but poorly understood, ways to bone function, motivates the method’s development, as does need for software tools to investigate relationships between macroscopic loading and micro-structure. Three applications – varying region of interest, bone mineral density, and orientation of collagen type I, illustrate the method. We show, in comparison between physiological loading and simple compression of a patient’s femur, that strains computed at the multi-scale model’s micro-level: (i) differ; and (ii) depend on local collagen-apatite orientation and degree of calcification. Our findings confirm the strain concentration role of osteocyte lacunae, important for mechano-transduction. We hypothesize occurrence of micro-crack formation, leading either to remodeling or macroscopic fracture, when the computed strains exceed the elastic range observed in micro-structural testing.
Determining matrix elements and resonance widths from finite volume: the dangerous mu-terms
G. Takacs
2011-10-10
The standard numerical approach to determining matrix elements of local operators and width of resonances uses the finite volume dependence of energy levels and matrix elements. Finite size corrections that decay exponentially in the volume are usually neglected or taken into account using perturbation expansion in effective field theory. Using two-dimensional sine-Gordon field theory as "toy model" it is shown that some exponential finite size effects could be much larger than previously thought, potentially spoiling the determination of matrix elements in frameworks such as lattice QCD. The particular class of finite size corrections considered here are mu-terms arising from bound state poles in the scattering amplitudes. In sine-Gordon model, these can be explicitly evaluated and shown to explain the observed discrepancies to high precision. It is argued that the effects observed are not special to the two-dimensional setting, but rather depend on general field theoretic features that are common with models relevant for particle physics. It is important to understand these finite size corrections as they present a potentially dangerous source of systematic errors for the determination of matrix elements and resonance widths.
Li, H.; Li, G., E-mail: gli@clemson.edu [College of Engineering and Science, Clemson University, Clemson, South Carolina 29634-0921 (United States)
2014-08-28
An accelerated Finite Element Contact Block Reduction (FECBR) approach is presented for computational analysis of ballistic transport in nanoscale electronic devices with arbitrary geometry and unstructured mesh. Finite element formulation is developed for the theoretical CBR/Poisson model. The FECBR approach is accelerated through eigen-pair reduction, lead mode space projection, and component mode synthesis techniques. The accelerated FECBR is applied to perform quantum mechanical ballistic transport analysis of a DG-MOSFET with taper-shaped extensions and a DG-MOSFET with Si/SiO{sub 2} interface roughness. The computed electrical transport properties of the devices obtained from the accelerated FECBR approach and associated computational cost as a function of system degrees of freedom are compared with those obtained from the original CBR and direct inversion methods. The performance of the accelerated FECBR in both its accuracy and efficiency is demonstrated.
Support graph preconditioning for elliptic finite element problems
Wang, Meiqiu
2009-05-15
A relatively new preconditioning technique called support graph preconditioning has many merits over the traditional incomplete factorization based methods. A major limitation of this technique is that it is applicable to ...
Notes 12. Finite element modeling of mechanical systems
San Andres, Luis
2008-01-01
Engineering calculations on PC's are undergoing a revolution with the advent of spreadsheet programs. The author has found that virtually all of the energy analysis types of programs can be cast into spreadsheet methods ...
Heat Transport in Groundwater Systems--Finite Element Model
Grubaugh, E. K.; Reddell, D. L.
1980-01-01
Solar energy is a promising alternate energy source for space heating. A method of economic long term solar energy storage is needed. Researchers have proposed storing solar energy by injecting hot water heated using solar collectors...
Iterative solutions to large sparse finite element equations
Wang, Hongbing
1995-01-01
for the direct and PCG methods using various storage formats. Effects of different material properties and external loading on the convergence rate and solution time are also analyzed. The test problems for this study are based on the three-dimensional linear...
Alternative Least-Squares Finite Element Models of Navier-Stokes Equations for Power-Law Fluids
Vallala, Venkat
2010-01-16
-Squares formulations of the original partial differential equations (PDE's) in terms of primary variables require C1 continuity of the finite element spaces across inter-element boundaries. This higherorder continuity requirement for PDE's in primary variables is a...
The Matrix Element Method and QCD Radiation
J. Alwall; A. Freitas; O. Mattelaer
2011-04-22
The matrix element method (MEM) has been extensively used for the analysis of top-quark and W-boson physics at the Tevatron, but in general without dedicated treatment of initial state QCD radiation. At the LHC, the increased center of mass energy leads to a significant increase in the amount of QCD radiation, which makes it mandatory to carefully account for its effects. We here present several methods for inclusion of QCD radiation effects in the MEM, and apply them to mass determination in the presence of multiple invisible particles in the final state. We demonstrate significantly improved results compared to the standard treatment.
On the validation of seismic imaging methods: Finite frequency or ray theory?
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Maceira, Monica; Larmat, Carene; Porritt, Robert W.; Higdon, David M.; Rowe, Charlotte A.; Allen, Richard M.
2015-01-23
We investigate the merits of the more recently developed finite-frequency approach to tomography against the more traditional and approximate ray theoretical approach for state of the art seismic models developed for western North America. To this end, we employ the spectral element method to assess the agreement between observations on real data and measurements made on synthetic seismograms predicted by the models under consideration. We check for phase delay agreement as well as waveform cross-correlation values. Based on statistical analyses on S wave phase delay measurements, finite frequency shows an improvement over ray theory. Random sampling using cross-correlation values identifiesmore »regions where synthetic seismograms computed with ray theory and finite-frequency models differ the most. Our study suggests that finite-frequency approaches to seismic imaging exhibit measurable improvement for pronounced low-velocity anomalies such as mantle plumes.« less
Finite-element discretization of a linearized 2 -D model for lubricated oil transportation
Frey, Pascal
Finite-element discretization of a linearized 2 - D model for lubricated oil transportation V is devoted to the numerical simulation of a linearized model for the lubricated trans- portation of heavy acts as a lubricant by coating the wall of the pipeline, thus preventing the oil from adhering
High Order Space-Time Finite Element Schemes for Acoustic and Viscodynamic Wave Equations with
High Order Space-Time Finite Element Schemes for Acoustic and Viscodynamic Wave Equations in time 5 3 Specific applications 10 3.1 The acoustic wave equation, for the first time, to second order wave equations including elastodynamics with and without Kelvin
High Order Space-Time Finite Element Schemes for Acoustic and Viscodynamic Wave Equations with
High Order Space-Time Finite Element Schemes for Acoustic and Viscodynamic Wave Equations applications are to the acoustic wave equation and to elastodynamics. We also build in the well-known Kelvin for decoupled DGFEM in time 6 3 Specific applications 10 3.1 The acoustic wave equation
Adaptive Finite Element Discretization of Flow Problems for Goal-Oriented Model Reduction
. The emphasis is on laminar viscous incompressible flows governed by the Navier-Stokes equations. But also computation in a laminar viscous fluid modeled by the sta- tionary Navier-Stokes equations for velocity vAdaptive Finite Element Discretization of Flow Problems for Goal-Oriented Model Reduction Rolf
Ewing, Richard E.
A ThreeÂDimensional Finite Element Simulation for Transport of Nuclear Waste ContaminationÂwaste contamination in threeÂdimensional porous media are presented with a description of linearization techniques contamination involving the transport of fluid, heat, brine, and traceÂspecies radionuclides by logically
Shape Design with Great Geometrical Deformations Using Continuously Moving Finite Element Nodes
Ring, Wolfgang
Shape Design with Great Geometrical Deformations Using Continuously Moving Finite Element Nodes B, University of Graz, Heinrichstrasse 36, AÂ8010 Graz, Austria Abstract --- In this paper design sensitivity on the design paÂ rameters. Since design sensitivity analysis is mainly applicable to optimization problems
Shape Design with Great Geometrical Deformations Using Continuously Moving Finite Element Nodes
Ring, Wolfgang
Shape Design with Great Geometrical Deformations Using Continuously Moving Finite Element Nodes B of Graz, Heinrichstrasse 36, A-8010 Graz, Austria Abstract | In this paper design sensitivity anal- ysis, it is necessary to assume a continuously di erentiable dependence of the sti ness matrix on the design pa
FINITE ELEMENT MODEL OF MICROELECTROMECHANICAL SYSTEMS SWITCH OPERATING AT MICROWAVE FREQUENCIES
De Flaviis, Franco
#12;FINITE ELEMENT MODEL OF MICROELECTROMECHANICAL SYSTEMS SWITCH OPERATING AT MICROWAVE@uci.edu The recent developments of microelectromechanical systems (MEMS) switch and their use at microwave frequencies have promoted exciting advancements in the field of microwave switching. In comparison with other
Thermo-elasto-plastic finite element analysis of quasi-state processes in Eulerian reference
Michaleris, Panagiotis
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
An Online Data Access System for a Finite Element Program , David Liu2
Stanford University
management in FEA programs still mainly rely on file systems. The prevailing data structures are based of the problems encountered by the prevailing data management based on file systems. Current trend sees retrieval. The online data access system gives great flexibility to the management of data in finite element
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER
Paris-Sud XI, Université de
FINITE ELEMENT MODEL-BASED STRUCTURAL HEALTH MONITORING (SHM) SYSTEMS FOR COMPOSITE MATERIAL UNDER). To design a Structural Health Monitoring (SHM) system, it is important to understand phenomenologically Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France Copyright © Inria (2014
A novel hybrid finite element model for modeling anisotropic composites Changyong Cao a
Qin, Qinghua
Composite materials Green's function Hybrid finite element Stroh formalism a b s t r a c t In this paper we-plane stiffness, bending stiffness, strength, and coef- ficient of thermal expansion (see Fig. 1) [1]. Individual layers (or laminae) of the laminates consist of high-modulus, high-strength fibers in a polymeric
Solid-mechanics finite element simulations of the draping of fabrics: a sensitivity analysis
Frey, Pascal
Solid-mechanics finite element simulations of the draping of fabrics: a sensitivity analysis L. Dong, C. Lekakou*, M.G. Bader School of Mechanical and Materials Engineering, University of Surrey into a "hat" shape, combining a hemispherical cup with a wide flat rim. A mechanical approach is adopted using
A mixed finite-element scheme of a semiconductor energy-transport model
Hanke-Bourgeois, Martin
A mixed finite-element scheme of a semiconductor energy-transport model using dual entropy which are able to deal with physical effects such as carrier heating and velocity overshoot. The energy that the Joule heating term vanishes if the dual entropy variables w1 = (Âµ - V )/T and w2 = -1/T are employed
A Finite Element Algorithm of a Nonlinear Diffusive Climate Energy Balance Model
DÃaz, JesÃºs Ildefonso
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
FINITE ELEMENT ANALYSIS OF A BENDING MOMENT FORMULATION FOR THE VIBRATION PROBLEM OF A
RodrÃguez, Rodolfo
FINITE ELEMENT ANALYSIS OF A BENDING MOMENT FORMULATION FOR THE VIBRATION PROBLEM OF A NON-HOMOGENEOUS TIMOSHENKO BEAM FELIPE LEPE, DAVID MORA, AND RODOLFO RODRÂ´IGUEZ Abstract. In this paper we analyze a low-homogeneous Timoshenko beam. We consider a formulation in which the bending moment is introduced as an additional unknown
Finite Element Solution of Optimal Control Problems Arising in Semiconductor Modeling
Siefert, Chris
- timization problem, especially for highly heterogeneous materials with large jumps in material properties. 1Finite Element Solution of Optimal Control Problems Arising in Semiconductor Modeling Pavel Bochev, and inverse problems arising in the modeling of semiconductor devices lead to optimization problems
Wadley, Haydn
The impact of sand slugs against beams and plates: Coupled discrete particle/finite element/continuum coupling Dynamic loading a b s t r a c t The impact of a slug of dry sand particles against a metallic for shock mitigation. The sand particles interact via a combined linear-spring-and-dashpot law whereas
FAST AND ACCURATE FINITE ELEMENT APPROXIMATION OF WAVE MAPS INTO SPHERES
. The scheme has a second order consistency property and is energy preserving and reversible. Its unconditional show in this article that a similar strategy can be applied for finite element discretizations this first-order system in time according to dtuk+1 = uk+1/2 × wk+1/2 , dtwk+1 = uk+1/2 × uk+1/2 , where dt
TIME DOMAIN ELECTROMAGNETIC SCATTERING USING FINITE ELEMENTS AND PERFECTLY MATCHED LAYERS
TIME DOMAIN ELECTROMAGNETIC SCATTERING USING FINITE ELEMENTS AND PERFECTLY MATCHED LAYERS H. T medium by a nonharmonic microwave pulse from an antenna source in free space, and we compute of the electromagnetic interrogation problems introduced in [3]. Here we use perfectly matched layers (PMLs) as absorbing
TIME DOMAIN ELECTROMAGNETIC SCATTERING USING FINITE ELEMENTS AND PERFECTLY MATCHED LAYERS
TIME DOMAIN ELECTROMAGNETIC SCATTERING USING FINITE ELEMENTS AND PERFECTLY MATCHED LAYERS H. T medium by a non-harmonic microwave pulse from an antenna source in free space, and we compute-dimensional version of the electromagnetic interrogation problems introduced in [3]. Here we use perfectly matched
Finite Elements in Analysis and Design 43 (2007) 397410 www.elsevier.com/locate/finel
Ghosh, Somnath
2007-01-01
Finite Elements in Analysis and Design 43 (2007) 397410 www.elsevier.com/locate/finel Modeling. Li, S. Ghosh Department of Mechanical Engineering, The Ohio State University, Columbus, OH, USA of damages is a challenging topic due to various kinematic and morphological complexities. Conventional
A Finite-Element Model for Simulation of Carbon Dioxide Sequestration
Bao, Jie; Xu, Zhijie; Fang, Yilin
2014-09-01
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 accurately—even 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.
Ghosh, Somnath
A size-dependent crystal plasticity finite-element model for creep and load shedding Abstract A rate-dependent anisotropic elastic-crystal plasticity based finite-element (FE) model with size in the crystal plasticity relations are expressed as HallPetch type relations, where the grain size, lath size
Müftü, Sinan
An Adaptive Finite Element Startegy for Analysis of Air Lubrication in the Head-Disk Interface, interface de tête-disque KEYWORDS: air lubrication, finite elements, adaptive mesh, head-disk interface #12). Air lubrication between the rotating disk and the slider is critical to maintain this gap; a delicate
Formulation and analysis of a three-dimensional finite element implementation for adhesive contact-dimensional finite element model for nanoscale contact problems with strong adhesion is presented. The contact the BF formulation but loses accuracy as the strength of adhesion increases. The model has applications
Fluorescence photon migration by the boundary element method
Fedele, Francesco; Eppstein, Margaret J. . E-mail: maggie.eppstein@uvm.edu; Laible, Jeffrey P.; Godavarty, Anuradha; Sevick-Muraca, Eva M.
2005-11-20
The use of the boundary element method (BEM) is explored as an alternative to the finite element method (FEM) solution methodology for the elliptic equations used to model the generation and transport of fluorescent light in highly scattering media, without the need for an internal volume mesh. The method is appropriate for domains where it is reasonable to assume the fluorescent properties are regionally homogeneous, such as when using highly specific molecularly targeted fluorescent contrast agents in biological tissues. In comparison to analytical results on a homogeneous sphere, BEM predictions of complex emission fluence are shown to be more accurate and stable than those of the FEM. Emission fluence predictions made with the BEM using a 708-node mesh, with roughly double the inter-node spacing of boundary nodes as in a 6956-node FEM mesh, match experimental frequency-domain fluorescence emission measurements acquired on a 1087 cm{sup 3} breast-mimicking phantom at least as well as those of the FEM, but require only 1/8 to 1/2 the computation time.
Percutaneous Mitral Valve Dilatation: Single Balloon versus Double Balloon - A Finite Element Study
Schievano, Silvia; Kunzelman, Karyn; Nicosia, Mark; Cochran, R. P.; Einstein, Daniel R.; Khambadkone, Sachin; Bonheoffer, Philipp
2009-01-01
Background: Percutaneous mitral valve (MV) dilatation is performed with either a single balloon (SB) or double balloon (DB) technique. The aim of this study was to compare the two balloon system results using the finite element (FE) method. Methods and Results: An established FE model of the MV was modified by fusing the MV leaflet edges at commissure level to simulate a stenotic valve (orifice area=180mm2). A FE model of a 30mm SB (low-pressure, elastomeric balloon) and an 18mm DB system (high-pressure, non-elastic balloon) was created. Both SB and DB simulations resulted in splitting of the commissures and subsequent stenosis dilatation (final MV area=610mm2 and 560mm2 respectively). Stresses induced by the two balloon systems varied across the valve. At the end of inflation, SB showed higher stresses in the central part of the leaflets and at the commissures compared to DB simulation, which demonstrated a more uniform stress distribution. The higher stresses in the SB analysis were due to the mismatch of the round balloon shape with the oval mitral orifice. The commissural split was not easily accomplished with the SB due to its high compliance. The high pressure applied to the DB guaranteed the commissural split even when high forces were required to break the commissure welds. Conclusions: The FE model demonstrated that MV dilatation can be accomplished by both SB and DB techniques. However, the DB method resulted in higher probability of splitting of the fused commissures and less damage caused to the MV leaflets by overstretching.
The inclusion of damage effects in an incremental finite element analysis of composite plates
Kilpatrick, Mark Christopher
1984-01-01
, boron, carbon, graphite) supported in polymeric matrices and later ln light weight metal matrices. (mme- diatelyo the analysis of fiber composites began. Analyses of Fiber composites are approached from the micro- or macro-mechanics view- point... for ihe degree of MASTER OF SCIENCE December 1984 Major Subject: Mechanical Engineering THE INCLUSION OF DAMAGE EFFECTS IN AN INCREMENTAL FINITE ELEMENT ANALYSIS OF COMPOSITE PLATES A Thesis by MARK CHRISTOPHER KILPATRICK Approved as to style...
Three dimensional finite element analysis of the flow of polymer melts
Jimack, Peter
Three dimensional finite element analysis of the flow of polymer melts R. Tencheva , T. Goughb , O.G, LS2 9JT, UK. b School of Engineering, Design & Technology, University of Bradford, Bradford, BD7 1DP.g.harlen@leeds.ac.uk (O.G. Harlen), p.k.jimack@leeds.ac.uk (P.K. Jimack), h.klein@leeds.ac.uk (D.H. Klein), m
Oelgaard, Kristian B; Wells, G N
2009-07-20
Optimisations for quadrature representations of finite element tensors through automated code generation KRISTIAN B. ØLGAARD Faculty of Civil Engineering and Geosciences Delft University of Technology and GARTH N. WELLS Department of Engineering... differential equations while achieving optimal or near-optimal run time performance is a possibility offered by K.B. Ølgaard, Faculty of Civil Engineering and Geosciences, Delft University of Technology Stev- inweg 1, 2628 CN Delft, Netherlands. Email: k.b...
Peng, McKenna, Fenves, Law1 An Open Collaborative Model for Development of Finite Element Program
Stanford University
a reality. The open source software development process reflects a powerful global trend toward networked and engineers can easily incorporate new element technologies and solution strategies. The distributed element engineering analysis programs. In current engineering practice, finite element packages need to be able
A Fourier-spectral-element method for transmission eigenvalue
2013-04-22
Abstract. We develop an efficient spectral-element method for computing the transmission eigenvalues in two-dimensional radially stratified media. Our method.
Finite element simulation of magnetic detection of creep damage at seam welds
Sablik, M.J.; Rubin, S.W.; Jiles, D.C.; Kaminski, D.; Bi, Y.
1996-09-01
Using appropriately modified magnetization curves for each element of creep-damaged material, a finite element calculation has been carried out to simulate magnetic detection of non-uniform creep damage around a seam weld in a 2.25 Cr 1 Mo steam pipe. The magnetization curves for the creep-damaged elements were obtained from an earlier model for the magnetic effect of a uniformly creep-damaged material as given by Chen, et al. In the finite element calculation, a magnetic C-core with primary and secondary coils was placed with its pole pieces flush against the specimen in the vicinity of the weld. The secondary emf was shown to be reduced when creep damage was present inside the pipe wall at the cusp of weld and in the vicinity of the cusp. The C-core detected the creep damage best if it completely spanned the weld seam width. Also, the current in the primary needed to be such that the C-core was not magnetically saturated.
A Stabilised Nodal Spectral Element Method for Fully Nonlinear Water Waves
Engsig-Karup, Allan Peter; Bigoni, Daniele
2015-01-01
We present an arbitrary-order spectral element method for general-purpose simulation of non-overturning water waves, described by fully nonlinear potential theory. The method can be viewed as a high-order extension of the classical finite element method proposed by Cai et al (1998) \\cite{CaiEtAl1998}, although the numerical implementation differs greatly. Features of the proposed spectral element method include: nodal Lagrange basis functions, a general quadrature-free approach and gradient recovery using global $L^2$ projections. The quartic nonlinear terms present in the Zakharov form of the free surface conditions can cause severe aliasing problems and consequently numerical instability for marginally resolved or very steep waves. We show how the scheme can be stabilised through a combination of over-integration of the Galerkin projections and a mild spectral filtering on a per element basis. This effectively removes any aliasing driven instabilities while retaining the high-order accuracy of the numerical...
A voxel-based finite element model for the prediction of bladder deformation
Chai Xiangfei; Herk, Marcel van; Hulshof, Maarten C. C. M.; Bel, Arjan [Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands); Radiation Oncology Department, Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands)
2012-01-15
Purpose: A finite element (FE) bladder model was previously developed to predict bladder deformation caused by bladder filling change. However, two factors prevent a wide application of FE models: (1) the labor required to construct a FE model with high quality mesh and (2) long computation time needed to construct the FE model and solve the FE equations. In this work, we address these issues by constructing a low-resolution voxel-based FE bladder model directly from the binary segmentation images and compare the accuracy and computational efficiency of the voxel-based model used to simulate bladder deformation with those of a classical FE model with a tetrahedral mesh. Methods: For ten healthy volunteers, a series of MRI scans of the pelvic region was recorded at regular intervals of 10 min over 1 h. For this series of scans, the bladder volume gradually increased while rectal volume remained constant. All pelvic structures were defined from a reference image for each volunteer, including bladder wall, small bowel, prostate (male), uterus (female), rectum, pelvic bone, spine, and the rest of the body. Four separate FE models were constructed from these structures: one with a tetrahedral mesh (used in previous study), one with a uniform hexahedral mesh, one with a nonuniform hexahedral mesh, and one with a low-resolution nonuniform hexahedral mesh. Appropriate material properties were assigned to all structures and uniform pressure was applied to the inner bladder wall to simulate bladder deformation from urine inflow. Performance of the hexahedral meshes was evaluated against the performance of the standard tetrahedral mesh by comparing the accuracy of bladder shape prediction and computational efficiency. Results: FE model with a hexahedral mesh can be quickly and automatically constructed. No substantial differences were observed between the simulation results of the tetrahedral mesh and hexahedral meshes (<1% difference in mean dice similarity coefficient to manual contours and <0.02 cm difference in mean standard deviation of residual errors). The average equation solving time (without manual intervention) for the first two types of hexahedral meshes increased to 2.3 h and 2.6 h compared to the 1.1 h needed for the tetrahedral mesh, however, the low-resolution nonuniform hexahedral mesh dramatically decreased the equation solving time to 3 min without reducing accuracy. Conclusions: Voxel-based mesh generation allows fast, automatic, and robust creation of finite element bladder models directly from binary segmentation images without user intervention. Even the low-resolution voxel-based hexahedral mesh yields comparable accuracy in bladder shape prediction and more than 20 times faster in computational speed compared to the tetrahedral mesh. This approach makes it more feasible and accessible to apply FE method to model bladder deformation in adaptive radiotherapy.
Lim, Jong Il
2007-04-25
Finite element analysis of electric double layer capacitors using a transient nonlinear Nernst-Planck-Poisson (NPP) model and Nernst-Planck-Poisson-modified Stern layer (NPPMS) model are presented in 1D and 2D. The NPP ...
Mukherjee, Souvik
2010-10-12
in both subsurface conductivity ? and relative permeability ?r. In this dissertation, I present a new three dimensional edge–based finite element (FE) algorithm capable of modeling the CSEM response of buried conductive and permeable targets. A coupled...
Victoria, University of
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
Finite element simulations of compositionally graded InGaN solar cells G.F. Brown a,b,n
Wu, Junqiao
for cheap multi-junction solar cells [4]. Previous simulations have shown that double-junction InxGa1ÀxFinite element simulations of compositionally graded InGaN solar cells G.F. Brown a,b,n , J.W. Ager conversion efficiency of compositionally graded InxGa1ÀxN solar cells was simulated using a finite element
Methods of exploring energy diffusion in lattices with finite temperature
Ping Hwang; Hong Zhao
2011-06-15
We discuss two methods for exploring energy diffusion in lattices with finite temperature in this paper. The first one is the energy-kick (EK) method. To apply this method, one adds an external energy kick to a particle in the lattice, and tracks its evolution by evolving the kicked system. The second one is the fluctuation-correlation (FC) method. The formula for calculating the probability density function (PDF) using the canonical ensemble is slightly revised and extended to the microcanonical ensemble. We show that the FC method has advantages over the EK method theoretically and technically. Theoretically, the PDF obtained by the FC method reveals the diffusion processes of the inner energy while the PDF obtained by the EK method represents that of the kick energy. The diffusion processes of the inner energy and the external energy added to the system, i.e., the kick energy, may be different quantitatively and even qualitatively depending on models. To show these facts, we study not only the equilibrium systems but also the stationary nonequilibrium systems. Examples showing that the inner energy and the kick energy may have different diffusion behavior are reported in both cases. The technical advantage enables us to study the long-time diffusion processes and thus avoids the finite-time effect.
Generalized spectral decomposition method for solving stochastic finite element equations
Paris-Sud XI, Université de
or stochastic bases, have been proposed in order to reduce these computational costs. Recently, a new ap- proach times and memory requirements. The reduction of these computational costs has now become a key question and the automatic construction of reduced bases. In this paper, the concept of GSD, initially introduced for a class
Convergence of goal-oriented adaptive finite element methods
Pollock, Sara
2012-01-01
v ? V T . w ? V T . The dual energy estimator is: ? T p (v, T ), v ? V T . The dual energy estimator is: ? T 2 , j (
Introduction of Finite Element Methods for Maxwell's Equations
2011-08-22
... fast algorithms have transformed the methodology for scientific investigation and industrial ... Students are required to present course-related material in class.
A VECTOR FINITE ELEMENT TIME-DOMAIN METHOD FOR ...
SIAM (#1) 1035 2001 Apr 10 12:32:38
2001-08-14
voltage standing wave ratio (VSWR), and reflection coefficient are shown in Table 8. .... C. D. Turner, VOLMAX: A solid model based transient volumetric Maxwell.
Revisiting stabilized finite element methods for the advectivediffusive equation
Masud, Arif
at Denver, P.O. Box 173364, Campus Box 170, Denver, CO 80217-3364, USA b Departamento de MecaÂ´nica de Fluidos, Centro PoliteÂ´cnico Superior, C/Maria de Luna 3, 50018 Zaragoza, Spain c Department of Civil
Uncoupled thermoelastic structural response by the finite element method
Linn, William Ray
1982-01-01
partial spacial derivatives and repeated indices imply summation), (k T ) P T[1+ 5( 1 & )( ? )] QT where (3X+2u) o T 6 6 v e (3) The style and citations of this thesis follow that of the 1 t'16166'1MttdJ~Eg where km is the thermal conductivity... ? ) + h(T -T) + sa(T -T ) + Q on I) (5) 3 BT 3 BT 4 v 3x x Bx By y By a r with the specified boundary conditions, T=T onl' s 1 (6a) k ? f. . + k ? / + h(T -T) + so(T "-T ) 0 on T (6b) x Bx x . y 3y y a r 2 where P, c?, T and T are defined as before...
INNOVATIVE FINITE ELEMENT METHODS FOR PLATES* DOUGLAS N. ARNOLD
Arnold, Douglas N.
equations. The ReissnerÂMindlin plate equations describe the bending of a linearly elastic plate in terms to moderate thickness. Assuming that the material is homogeneous and isotropic with Young's modulus E are minimizers of the energy functional (, ) J(, ) := 1 2 C E() : E() + 1 2 t-2 | grad - |2 - g dx, *Paper
NONNESTED MULTIGRID METHODS IN FINITE ELEMENT LINEAR STRUCTURAL ANALYSIS
Departamento de Projeto Mecâ??anico (DPM), Faculdade de Engenharia Mecâ??anica (FEM), UniÂ versidade Estadual de
The generalized finite element method applied to the dynamic...
Office of Scientific and Technical Information (OSTI)
Relation: Conference: Proposed for presentation at the Advances in Computational Mechanics held February 24-28, 2013 in San Diego, CA. Research Org: Sandia National...
An Implementation of the Generalized Finite Element Method for...
Office of Scientific and Technical Information (OSTI)
Type: Conference Resource Relation: Conference: US National Congress on Computational Mechanics held July 16-19, 2009 in Columbus, OH.; Related Information: Proposed for...
Extended Finite Element Method for Fretting Fatigue Crack Propagation
Sukumar, N.
.D. Denia a , F.J. Fuenmayor a aDepartamento de Ingenier´ia Mec´anica y de Materiales Universidad Polit
An Abaqus implementation of the extended finite element method
Sukumar, N.
. Taranc´on a , F. J. Fuenmayor a aDepartamento de Ingenier´ia Mec´anica y de Materiales Universidad Polit
Coupling of finite element and boundary integral methods for ...
"Peijun Li"
2009-11-09
Oct 8, 2009 ... for open-region problems involving complex structures and ...... G. Schmidt, Diffraction in periodic structures and optimal design of binary ...
MA690: Introduction of Finite Element Methods for Maxwell's ...
2011-03-28
ods to describe the scattering of complicated structures, and to compute ... of a given structure, as well as to carry out optimal design of new structures. The.
stabilized finite element methods for coupled geomechanics and ...
7.19 Water saturation map by FCM and FEAST model at t = 1600 days . 110 .... The Wilmington oil field is located in Long Beach, California. Subsidence was first.
Mixed finite element methods for incompressible flow: Stationary ...
2010-04-14
May 14, 2009 ... ... grant sponsor: U.S. Department of Energy by University of California .... for the resulting discrete system so that computational cost will be ...
Accepted Manuscript A finite element method for viscous membranes
Buscaglia, Gustavo C.
´ifica, Brazil Abstract The simulation of biological interfaces at the Living Cell scale relies on mem- brane
A finite element method using singular functions for the Poisson ...
2002-09-05
Contract=grant sponsor: U.S. Department of Energy by Lawrence Livermore ... Contract=grant sponsor: Institute of Basic Science, Changwon National University.
Stochastic finite element methods for partial differential equations with
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System inStatus of the MEIC ionConnectrandom input data
A finite element model for transient thermal/structural analysis of large composite space structures
Lutz, James Delmar
1986-01-01
Composite Space Structures. (May 1986) James Delmar Lutz, B. S. , Texas A&M University Chairmen of Advisory Committee: Dr. David H. Allen Dr. Walter E. Haisler A finite element model is developed for predicting the transient thermal/structural response... of structures to be analyzed in order to simplify the heat load analysis. The first r estr iction applies to the geometry of struc- tures to be analyzed. An appropriate structure should be of open lattice-type construction and have highly repetitive...
Finite element analysis of surface-stress effects in the Si lattice-parameter measurement
Sasso, Carlo; Massa, Enrico; Mana, Giovanni; Kuetgens, Ulrich
2013-01-01
A stress exists in solids surfaces, similarly to liquids, also if the underlying bulk material is stress-free. This paper investigates the surface stress effect on the measured value of the Si lattice parameter used to determine the Avogadro constant by counting Si atoms. An elastic-film model has been used to provide a surface load in a finite element analysis of the lattice strain of the x-ray interferometer crystal used to measure the lattice parameter. Eventually, an experiment is proposed to work a lattice parameter measurement out so that there is a visible effect of the surface stress.
A finite element analysis of a silicon based double quantum dot structure
S. Rahman; J. Gorman; C. H. W. Barnes; D. A. Williams; H. P. Langtangen
2006-04-06
We present the results of a finite-element solution of the Laplace equation for the silicon-based trench-isolated double quantum-dot and the capacitively-coupled single-electron transistor device architecture. This system is a candidate for charge and spin-based quantum computation in the solid state, as demonstrated by recent coherent-charge oscillation experiments. Our key findings demonstrate control of the electric potential and electric field in the vicinity of the double quantum-dot by the electric potential applied to the in-plane gates. This constitutes a useful theoretical analysis of the silicon-based architecture for quantum information processing applications.
Mourad, Hashem M [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory
2010-12-16
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.
Finite element thermomechanical simulation of droplets impacting on a rigid substrate
Bertagnolli, M.; Marchese, M.; Jacucci, G.; St. Doltsinis, I.; Noelting, S.
1994-12-31
The plasma spray process is a convenient way to coat a piece of material with a layer of another material, to protect the first from thermal shock or environmental degradation. Finite Element simulation techniques (FEM) for the spreading process of a ceramic liquid droplet impacting on a flat cold surface have been developed. The goal of the present investigation is (1) to predict the geometrical form of the splat as a function of process parameters, such as initial temperature and velocity, and (2) to follow the thermal field developing in the droplet up to solidification. A non-linear finite element procedure has been extended in order to model the complex physical phenomena involved in the impact process. The dynamic motion of the viscous melt in the drops as constrained by elastic surface tensions in interaction with the developing contact with the target, ultimately has been coupled to transient thermal phenomena accounting also for the solidification of the material. In a first model description, spherical particles of liquid ceramic of given temperature and velocity impact on a flat, cool rigid surface. The deformation of the splat geometry as well as the evolution of the thermal field within the splat are followed up to the final state and require adaptive discretization techniques. The authors discuss an utilization of the proposed model in correlating flattening degrees with the initial process parameters.
Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas
2014-04-23
Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).
Efficient Computation of Info-Gap Robustness for Finite Element Models
Stull, Christopher J.; Hemez, Francois M.; Williams, Brian J.
2012-07-05
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.
Grujicic, Mica
Finite element analysis of the effect of up-armouring on the off-road braking and sharp-mobility multi-purpose wheeled vehicle, off-road vehicle performance, finite element modelling and simulations revision for publication on 15 June 2009. DOI: 10.1243/09544070JAUTO1187 Abstract: A comprehensive finite
Automation of the matrix element reweighting method
P. Artoisenet; V. Lemaître; F. Maltoni; O. Mattelaer
2011-02-01
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.
Validation of Finite-Element Models of Persistent-Current Effects in Nb3Sn Accelerator Magnets
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wang, X.; Ambrosio, G.; Chlachidze, G.; Collings, E. W.; Dietderich, D. R.; DiMarco, J.; Felice, H.; Ghosh, A. K.; Godeke, A.; Gourlay, S. A.; et al
2015-01-06
Persistent magnetization currents are induced in superconducting filaments during the current ramping in magnets. The resulting perturbation to the design magnetic field leads to field quality degradation, in particular at low field where the effect is stronger relative to the main field. The effects observed in NbTi accelerator magnets were reproduced well with the critical-state model. However, this approach becomes less accurate for the calculation of the persistent-current effects observed in Nb3Sn accelerator magnets. Here a finite-element method based on the measured strand magnetization is validated against three state-of-art Nb3Sn accelerator magnets featuring different subelement diameters, critical currents, magnet designsmore »and measurement temperatures. The temperature dependence of the persistent-current effects is reproduced. Based on the validated model, the impact of conductor design on the persistent current effects is discussed. The performance, limitations and possible improvements of the approach are also discussed.« less
Christian Kreuzer; Endre Süli
2015-03-18
We develop the a posteriori error analysis of finite element approximations of implicit power-law-like models for viscous incompressible fluids. The Cauchy stress and the symmetric part of the velocity gradient in the class of models under consideration are related by a, possibly multi--valued, maximal monotone $r$-graph, with $\\frac{2d}{d+1}finite element residual, as well as the local stability of the error bound. We then consider an adaptive finite element approximation of the problem, and, under suitable assumptions, we show the weak convergence of the adaptive algorithm to a weak solution of the boundary-value problem. The argument is based on a variety of weak compactness techniques, including Chacon's biting lemma and a finite element counterpart of the Acerbi--Fusco Lipschitz truncation of Sobolev functions, introduced by L. Diening, C. Kreuzer and E. S\\"uli [Finite element approximation of steady flows of incompressible fluids with implicit power-law-like rheology. SIAM J. Numer. Anal., 51(2), 984--1015].
Superconvergence of finite element approximations by a computer-based approach
Gangaraj, Srihari Kumar
1994-01-01
%-SUPERCONVERGENCE . . 5. 1 Preliminaries . . 5. 2 The method of freezing the periodicity 5. 3 Numerical studies of g%-superconvergence . 5. 4 Summary 74 74 79 84 192 CHAPTER VI SUMMARY OF CONCLUSIONS . 6. 1 Conclusions based on this study 6. 2 Directions... shown i? (. I) u it I& tl a?shin? cl& n&cn(s: (&I) The mesh- patch of 1?qu &drat i?l& ln& n(s sh&&n? i? (I&) (vith j la?slllon clem&&nts. 66 73 Figure Figure Figurc Figure Figure 5. 2. Method ol' I& ppzi?g thc pcl'lo&licijy: (a) A finit& elr?1...
Method of holding optical elements without deformation during their fabrication
Hed, P. Paul (80 Milaw Ct., San Ramon, CA 94583)
1997-01-01
An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool.
Condition Numbers in the Boundary Element Method
Hochstenbach, Michiel
methods / numerical simulation / Navier-Stokes equations / glass 2000 Mathematics Subject Classification . . . . . . . . . . . . . . . . . . . . . . . . . 76 5.6 Blowing problem in 2D . . . . . . . . . . . . . . . . . . . . . . . . 86
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,
2012-01-01
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.
Finite element residual stress analysis of induction heating bended ferritic steel piping
Kima, Jong Sung; Kim, Kyoung-Soo; Oh, Young-Jin; Chang, Hyung-Young; Park, Heung-Bae
2014-10-06
Recently, there is a trend to apply the piping bended by induction heating process to nuclear power plants. Residual stress can be generated due to thermo-mechanical mechanism during the induction heating bending process. It is well-known that the residual stress has important effect on crack initiation and growth. The previous studies have focused on the thickness variation. In part, some studies were performed for residual stress evaluation of the austenitic stainless steel piping bended by induction heating. It is difficult to find the residual stresses of the ferritic steel piping bended by the induction heating. The study assessed the residual stresses of induction heating bended ferriticsteel piping via finite element analysis. As a result, it was identified that high residual stresses are generated on local outersurface region of the induction heating bended ferritic piping.
Finite element analysis of three TVA dams with alkali-aggregate reaction
Grenoble, B.A.; Meisenheimer, J.K.; Wagner, C.D.; Newell, V.A.
1995-12-31
Three large Tennessee Valley Authority (TVA) dams are currently experiencing problems caused by alkali-aggregate reaction (AAR). Since the fall of 1990, engineers in Stone & Webster`s Denver, Colorado office have been working with TVA to evaluate how AAR is affecting the dams and to identify measures for controlling the adverse effects of the concrete growth. This paper provides an overview of how finite element analysis is being used to understand the affects of AAR on these structures and to evaluate alternatives for minimizing the adverse effects of the concrete growth. Work on Hiwassee Dam is essentially complete, while that on the Chickamauga and Fontana Projects is still in progress. Consequently, this paper will focus primarily on Hiwassee Dam. The ongoing work on the other two projects will only be discussed briefly.
Robert M. Parrish; Edward G. Hohenstein; Nicolas F. Schunck; C. David Sherrill; Todd J. Martinez
2013-09-05
Configuration-space matrix elements of N-body potentials arise naturally and ubiquitously in the Ritz-Galerkin solution of many-body quantum problems. For the common specialization of local, finite-range potentials, we develop the eXact Tensor HyperContraction (X-THC) method, which provides a quantized renormalization of the coordinate-space form of the N-body potential, allowing for a highly separable tensor factorization of the configuration-space matrix elements. This representation allows for substantial computational savings in chemical, atomic, and nuclear physics simulations, particularly with respect to difficult "exchange-like" contractions.
Block-structured Adaptive Finite Volume Methods for Shock-Induced Combustion
Deiterding, Ralf
Block-structured Adaptive Finite Volume Methods for Shock-Induced Combustion Simulation Ralf-Induced Combustion Simulation 1 #12;Structure of the lectures Block-structured Adaptive Finite Volume Methods for Shock-Induced Combustion Simulation 2 #12;Structure of the lectures 1. Fundamentals of finite volume
Resolution of grain scale interactions using the Discrete Element Method
Johnson, Scott M. (Scott Matthew), 1978-
2006-01-01
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, ...
Marlin, Benjamin
Motivation Gradient Method Stochastic Subgradient Finite-Sum Methods Non-Smooth Objectives Modern) International Conference on Machine Learning Peter RichtÂ´arik and Mark Schmidt July 2015 #12;Motivation Gradient. Not gigabytes, but terabytes or petabytes (and beyond). #12;Motivation Gradient Method Stochastic Subgradient
Methods and devices for fabricating and assembling printable semiconductor elements
Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao
2014-03-04
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.
Methods and devices for fabricating and assembling printable semiconductor elements
Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao
2013-05-14
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.
Methods and devices for fabricating and assembling printable semiconductor elements
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)
2011-07-19
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.
Methods and devices for fabricating and assembling printable semiconductor elements
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)
2009-11-24
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.
E. Sun, P. Brindza, S. Lassiter, M. Fowler, E. Xu
2010-06-01
This paper presents coupled transient thermal and electromagnetic finite element analysis of quench in the Q2, Q3, and dipole superconducting magnets using Vector Fields Quench code. Detailed temperature distribution within coils and aluminum force collars were computed at each time step. Both normal (quench with dump resistor) and worst-case (quench without dump resistor) scenarios were simulated to investigate the maximum temperatures. Two simulation methods were utilized, and their algorithms, implementation, advantages, and disadvantages are discussed. The first method simulated the coil using nonlinear transient thermal analysis directly linked with the transient circuit analysis. It was faster because only the coil was meshed and no eddy current was modeled. The second method simulated the whole magnet including the coil, the force collar, and the iron yoke. It coupled thermal analysis with transient electromagnetic field analysis which modeled electromagnetic fields including eddy currents within the force collar. Since eddy currents and temperature in the force collars were calculated in various configurations, segmentation of the force collars was optimized under the condition of fast discharge.
Payan, Yohan
/lower lip contacts are also modeled. Simulations of smiling and of an Orbicularis Oris activationAbstract: A 3D biomechanical finite element model of the face is presented. Muscles are represented the mesh or the muscle implementation totally independently of each other. Lip/teeth and upper lip
Ewing, Richard E.
A ThreeÂDimensional Finite Element Simulation for Transport of Nuclear Waste Contamination for transport of nuclearÂwaste contamination in threeÂdimensional porous media are presented with a description waste contamination involving the transport of fluid, heat, brine, and traceÂspecies radionuclides
Patzek, Tadeusz W.
the geomechanics of oil and gas reservoirs. The fragile microstructure of some rocks makes it difficult to predict of Steel, Aluminum, Concrete, etc. Moreover, the pattern of rock damage in oil and gas reservoirsFinite Element Solution of Nonlinear Transient Rock Damage with Application in Geomechanics of Oil
An implicit finite-element model for 3D non-hydrostatic mesoscale ocean M.A. Maidana1
Politècnica de Catalunya, Universitat
An implicit finite-element model for 3D non-hydrostatic mesoscale ocean flows M.A. Maidana1 , J-dimensional, non-hydrostatic mesoscale ocean flows. The model considered here incorporates surface wind stress and the idea of using unstructured grids for modelling mesoscale ocean dynamics sounds very attractive given
Terzopoulos, Demetri
, PET and other noninvasive medical imaging technologies can provide exceptional views of internal elastically to t the image data. The tting process is mediated by internal forces stemming from the elastic tting process. Keywords: 3D/4D Medical Image Analysis, Deformable Models, Finite Elements, Dynamics
Yaman, Yavuz
VERIFICATION OF A FINITE ELEMENT MODEL OF AN UNMANNED AERIAL VEHICLE WING TORQUE BOX VIA Aeronautical Association, Faculty of Aeronautics and Astronautics, TURKEY KEYWORDS Unmanned Aerial Vehicle Wing (FEM) of an unmanned aerial vehicle wing torque box was verified by the experimental modal testing
A Layerwise Shell Stiffener and Stand-Alone Curved Beam Element
Kassegne, Samuel Kinde
for the analysis of stiffened plates and shells. The finite element method has been used by a number elements. The element can also be used as a stand-alone curved or straight beam element. A finite element and Schnobrich [1] proposed a sixteen degrees of freedom isotropic beam finite element which has a displacement
Incorporation and modification of a shear deformable finite element into MARC
Hofman, Brad Burdell
1996-01-01
The proposed research focuses on implementing an existing shear deformable composite element as a user element in MARC[]. Furthermore, the element is enhanced by developing an algorithm to accommodate variable thickness within an element...
On the validation of seismic imaging methods: Finite frequency...
Office of Scientific and Technical Information (OSTI)
as well as waveform cross-correlation values. Based on statistical analyses on S wave phase delay measurements, finite frequency shows an improvement over ray theory. Random...
Quinones, Armando, Sr. (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei
2008-08-01
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).
Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.
Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay
2012-01-01
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.
Christian, Joshua M.; Ho, Clifford Kuofei
2010-04-01
Understanding the effects of gravity and wind loads on concentrating solar power (CSP) collectors is critical for performance calculations and developing more accurate alignment procedures and techniques. This paper presents a rigorous finite-element model of a parabolic trough collector that is used to determine the impact of gravity loads on bending and displacements of the mirror facets and support structure. The geometry of the LUZ LS-2 parabolic trough collector was modeled using SolidWorks, and gravity-induced loading and displacements were simulated in SolidWorks Simulation. The model of the trough collector was evaluated in two positions: the 90{sup o} position (mirrors facing upward) and the 0{sup o} position (mirrors facing horizontally). The slope errors of the mirror facet reflective surfaces were found by evaluating simulated angular displacements of node-connected segments along the mirror surface. The ideal (undeformed) shape of the mirror was compared to the shape of the deformed mirror after gravity loading. Also, slope errors were obtained by comparing the deformed shapes between the 90{sup o} and 0{sup o} positions. The slope errors resulting from comparison between the deformed vs. undeformed shape were as high as {approx}2 mrad, depending on the location of the mirror facet on the collector. The slope errors resulting from a change in orientation of the trough from the 90{sup o} position to the 0{sup o} position with gravity loading were as high as {approx}3 mrad, depending on the location of the facet.
Finite element modelling of shock-induced damages on ceramic hip prostheses
Uribe, Juliana; Geringer, Jean; 10.5402/2011/121486
2012-01-01
The aim of this work was to simulate the behaviour of hip prostheses under mechanical shocks. When hip joint is replaced by prosthesis, during the swing phase of the leg, a microseparation between the prosthetic head and the cup could occur. Two different sizes of femoral heads were studied: 28 and 32 mm diameter, made, respectively, in alumina and zirconia. The shock-induced stress was determined numerically using finite element analysis (FEA), Abaqus software. The influence of inclination, force, material, and microseparation was studied. In addition, an algorithm was developed from a probabilistic model, Todinov's approach, to predict lifetime of head and cup. Simulations showed maximum tensile stresses were reached on the cup's surfaces near to rim. The worst case was the cup-head mounted at 30^{\\circ}. All simulations and tests showed bulk zirconia had a greater resistance to shocks than bulk alumina. The probability of failure could be bigger than 0.9 when a porosity greater than 0.7% vol. is present in...
Method of holding optical elements without deformation during their fabrication
Hed, P.P.
1997-04-29
An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element is disclosed. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool. 16 figs.
Iskander, S.K.
1981-02-01
Two finite element (FE) approaches were used to calculate opening mode I stress intensity factors (K/sub I/) in two- or three-dimensional (2-D and 3-D) problems for the Heavy-Section Steel Technology (HSST) program. For problems that can be modeled in two dimensions, two techniques were used. One of these may be termed an ''energy release rate'' technique, and the other is based on the classical near-tip displacement and stress field equations. For three-dimensional problems, only the latter technique was used. In the energy release technique, K/sub I/ is calculated as the change in potential energy of the structure due to a small change in crack length. The potential energy is calculated by the FE method but without completely solving the system of linear equations for the displacements. Furthermore, the system of linear equations is only slightly perturbed by the change in crack length and, therefore, many computations need not be repeated for the second structure with the slight change in crack length. Implementation of these last two items has resulted in considerable savings in the calculation of K/sub I/ as compared to two complete FE analyses. These ideas are incorporated in the FMECH code. The accuracy of the methods has been checked by comparing the results of the two approaches with each other and with closed form solutions. It is estimated that the accuracy of the results is about +-5%.
Collins, Gary S.
Discussion Data collected here will aid researchers in creating a more accurate crystal plasticity grant number DMR-1062898. Introduction Although various crystal plasticity finite element models (CPFEMs Â· Provide data for researchers to create crystal plasticity finite element models (CPFEM) that characterize
Zhou, Jack
"FINITE ELEMENT ANALYSIS ASSISTED HOT BAR BLADE DESIGN," Jack. Zhou, Li Zhuang, Zongyan He, Maryland, June 2000. FINITE ELEMENT ANALYSIS ASSISTED HOT BAR BLADE DESIGN Jack. Zhou, Li Zhuang in fabrication of cellular phones for many years. The existing hot bar blade design has two defects
Method and system for high power reflective optical elements
Demos, Stavros G.; Rubenchik, Alexander M.; Negres, Raluca A.
2013-03-12
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.
Bandaru, Vinodh; Krasnov, Dmitry; Schumacher, Jörg
2015-01-01
A conservative coupled finite difference-boundary element computational procedure for the simulation of turbulent magnetohydrodynamic flow in a straight rectangular duct at finite magnetic Reynolds number is presented. The flow is assumed to be periodic in the streamwise direction and is driven by a mean pressure gradient. The duct walls are considered to be electrically insulating. The co-evolution of the velocity and magnetic fields as described respectively by the Navier-Stokes and the magnetic induction equations, together with the coupling of the magnetic field between the conducting domain and the non-conducting exterior is solved using the magnetic field formulation. The aim is to simulate localized magnetic fields interacting with turbulent duct flow. Detailed verification of the implementation of the numerical scheme is conducted in the limiting case of low magnetic Reynolds number by comparing with the results obtained using a quasistatic approach that has no coupling with the exterior. The rigorous...
A stochastic method for computing hadronic matrix elements
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Alexandrou, Constantia; Constantinou, Martha; Dinter, Simon; Drach, Vincent; Jansen, Karl; Hadjiyiannakou, Kyriakos; Renner, Dru B.
2014-01-24
In this study, 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.
Morris, J; Johnson, S
2007-12-03
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.
Nuclear fuel elements and method of making same
Schweitzer, Donald G. (Bayport, NY)
1992-01-01
A nuclear fuel element for a high temperature gas nuclear reactor that has an average operating temperature in excess of 2000.degree. C., and a method of making such a fuel element. The fuel element is characterized by having fissionable fuel material localized and stabilized within pores of a carbon or graphite member by melting the fissionable material to cause it to chemically react with the carbon walls of the pores. The fissionable fuel material is further stabilized and localized within the pores of the graphite member by providing one or more coatings of pyrolytic carbon or diamond surrounding the porous graphite member so that each layer defines a successive barrier against migration of the fissionable fuel from the pores, and so that the outermost layer of pyrolytic carbon or diamond forms a barrier between the fissionable material and the moderating gases used in an associated high temperature gas reactor. The method of the invention provides for making such new elements either as generally spherically elements, or as flexible filaments, or as other relatively small-sized fuel elements that are particularly suited for use in high temperature gas reactors.
MODELING OF HIGH SPEED FRICTION STIR SPOT WELDING USING A LAGRANGIAN FINITE ELEMENT APPROACH
Miles, Michael; Karki, U.; Woodward, C.; Hovanski, Yuri
2013-09-03
Friction stir spot welding (FSSW) has been shown to be capable of joining steels of very high strength, while also being very flexible in terms of controlling the heat of welding and the resulting microstructure of the joint. This makes FSSW a potential alternative to resistance spot welding (RSW) if tool life is sufficiently high, and if machine spindle loads are sufficiently low so that the process can be implemented on an industrial robot. Robots for spot welding can typically sustain vertical loads of about 8kN, but FSSW at tool speeds of less than 3000 rpm cause loads that are too high, in the range of 11-14 kN. Therefore, in the current work tool speeds of 3000 rpm and higher were employed, in order to generate heat more quickly and to reduce welding loads to acceptable levels. The FSSW process was modeled using a finite element approach with the Forge® software package. An updated Lagrangian scheme with explicit time integration was employed to model the flow of the sheet material, subjected to boundary conditions of a rotating tool and a fixed backing plate [3]. The modeling approach can be described as two-dimensional, axisymmetric, but with an aspect of three dimensions in terms of thermal boundary conditions. Material flow was calculated from a velocity field which was two dimensional, but heat generated by friction was computed using a virtual rotational velocity component from the tool surface. An isotropic, viscoplastic Norton-Hoff law was used to model the evolution of material flow stress as a function of strain, strain rate, and temperature. The model predicted welding temperatures and the movement of the joint interface with reasonable accuracy for the welding of a dual phase 980 steel.
Hoffman, E.L.; Ammerman, D.J.
1993-08-01
A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several finite element simulations of the event. The purpose of the study is to compare the performance of the various analysis codes and element types with respect to a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry.
Woodward, Carol S.; Gardner, David J.; Evans, Katherine J.
2015-01-01
Efficient solutions of global climate models require effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a step size governed by accuracy of the processes of interest rather than by stability of the fastest time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton's method is applied to solve these systems. Each iteration of the Newton's method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but this Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite difference approximation which may introduce inaccuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite difference approximations of these matrix-vector products for climate dynamics within the spectral element shallow water dynamical core of the Community Atmosphere Model.
Gardner, David; Woodward, Carol S.; Evans, Katherine J
2015-01-01
Efficient solution of global climate models requires effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a time step dictated by accuracy of the processes of interest rather than by stability governed by the fastest of the time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton s method is applied for these systems. Each iteration of the Newton s method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but this Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite-difference which may show a loss of accuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite-difference approximations of these matrix-vector products for climate dynamics within the spectral-element based shallow-water dynamical-core of the Community Atmosphere Model (CAM).
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Woodward, Carol S.; Gardner, David J.; Evans, Katherine J.
2015-01-01
Efficient solutions of global climate models require effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a step size governed by accuracy of the processes of interest rather than by stability of the fastest time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton's method is applied to solve these systems. Each iteration of the Newton's method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but thismore »Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite difference approximation which may introduce inaccuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite difference approximations of these matrix-vector products for climate dynamics within the spectral element shallow water dynamical core of the Community Atmosphere Model.« less
A posteriori error analysis for a finite volume method
Tavener, Simon
of nuclear fuel rods, electrical impedance tomography · Pose well known challenges for accurate numerical interface method · Fictitious domain method · Ghost fluid method · (Immersed boundary method
Method and apparatus for diagnosing breached fuel elements
Gross, K.C.; Lambert, J.D.B.; Nomura, S.
1987-03-02
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.
Method and apparatus for diagnosing breached fuel elements
Gross, Kenny C. (Lemont, IL); Lambert, John D. B. (Wheston, IL); Nomura, Shigeo (Mito, JP)
1988-01-01
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 cure 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.
Appelö, Daniel
; curvilinear grids ; finite differences; stability; energy estimate; seismic wave propagation 1 IntroductionA stable finite difference method for the elastic wave equation on complex geometries with free Institute of Technology, Pasadena, CA 91125, USA 2 Center for Applied and Scientific Computing, Lawrence
Method for measuring recovery of catalytic elements from fuel cells
Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley, NJ)
2011-03-08
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.
Method for detection of antibodies for metallic elements
Barrick, C.W.; Clarke, S.M.; Nordin, C.W.
1993-11-30
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.
Computational Solid Mechanics using a Vertex-based Finite Volume Method
Taylor, Gary
Computational Solid Mechanics using a Vertex-based Finite Volume Method G. A. Taylor, C. Bailey and using nite volume (FV) methods for computational solid mechanics (CSM). These methods are proving]. As a contemporary, the FV method has similarlyestablished itself within the eld of computational uid dynamics (CFD
Finite volume evolution Galerkin method for hyperbolic conservation laws with spatially varying
Galerkin scheme, finite volume methods, bicharacteristics, wave equation, heterogeneous media, acoustic equation system with spatially varying wave speeds and simulate the propagation of acoustic waves for wave propagation problems in a heterogeneous media. We illustrate our methodology for acoustic waves
A non-linear constrained optimization technique for the mimetic finite difference method
Manzini, Gianmarco; Svyatskiy, Daniil; Bertolazzi, Enrico; Frego, Marco
2014-09-30
This is a strategy for the construction of monotone schemes in the framework of the mimetic finite difference method for the approximation of diffusion problems on unstructured polygonal and polyhedral meshes.
Efficient numerical methods for capacitance extraction based on boundary element method
Yan, Shu
2006-04-12
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...
LOWER TRANSIENT STRESSES IN AN AORTIC VALVE LEAFLET WITH OBLIQUE REINFORCEMENT FIBERS: A FINITE Cambridge, MA, USA INTRODUCTION Native aortic valve leaflets contain a network of strong collagen fibers the stresses of cyclic loading over billions of heart beats. Replacement valves that consist of animal tissues
Liu, Mian
How does trench coupling lead to mountain building in the Subandes? A viscoelastoplastic finite cause of the Andean mountain building. The present-day crustal shortening in the Andes is clear from the cyclic trench coupling leads to long-term mountain building, which has been concentrated in the Subandes
Linker, K.L.; Rawlinson, K.S.; Smith, G.
1991-10-01
The Department of Energy's Solar Thermal Program has as one of its program elements the development and evaluation of conversion device technologies applicable to dish-electric systems. The primary research and development combines a conversion device (heat engine), solar receiver, and generator mounted at the focus of a parabolic dish concentrator. The Stirling-cycle heat engine was identified as the conversion device for dish-electric with the most potential for meeting the program's goals for efficiency, reliability, and installed cost. To advance the technology toward commercialization, Sandia National Laboratories has acquired a Stirling Thermal Motors, Inc., kinematic Stirling engine, STM4-120, for evaluation. The engine is being bench-tested at Sandia's Engine Test Facility and will be combined later with a solar receiver for on-sun evaluation. This report presents the engine characteristics, finite element analyses of critical engine components, test system layout, instrumentation, and preliminary performance results from the bench test.
The Matrix Element Method: Past, Present, and Future
James S. Gainer; Joseph Lykken; Konstantin T. Matchev; Stephen Mrenna; Myeonghun Park
2013-07-26
The increasing use of multivariate methods, and in particular the Matrix Element Method (MEM), represents a revolution in experimental particle physics. With continued exponential growth in computing capabilities, the use of sophisticated multivariate methods-- already common-- will soon become ubiquitous and ultimately almost compulsory. While the existence of sophisticated algorithms for disentangling signal and background might naively suggest a diminished role for theorists, the use of the MEM, with its inherent connection to the calculation of differential cross sections will benefit from collaboration between theorists and experimentalists. In this white paper, we will briefly describe the MEM and some of its recent uses, note some current issues and potential resolutions, and speculate about exciting future opportunities.
Higher-Order Spectral/HP Finite Element Technology for Structures and Fluid Flows
Vallala, Venkat Pradeep
2013-06-20
This study deals with the use of high-order spectral/hp approximation functions in the ?nite element models of various nonlinear boundary-value and initial-value problems arising in the ?elds of structural mechanics and ...
Jiang, Lijian
2009-05-15
porous media, oil reservoir simulations and subsurface characterization. In the work, we investigate three main multiscale numerical methods, i.e., multiscale finite element method, partition of unity method and mixed multiscale finite element method...
REMARKS ON THE MAXIMUM ENTROPY METHOD APPLIED TO FINITE TEMPERATURE LATTICE QCD.
UMEDA, T.; MATSUFURU, H.
2005-07-25
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.
On simple and accurate finite element models for nonlinear bending analysis of beams and plates
Urthaler Lapeira, Yetzirah Yksya
2007-09-17
–ce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, J.N. Reddy Committee Members, Steve Suh Harry Hogan Goong Chen Head of Department, Dennis O’Neal May... Bolivar Chair of Advisory Committee: Dr. J.N. Reddy This study is concerned with the development of simple and accurate alterna- tive flnite element models to displacement flnite element models for geometrically nonlinear bending analysis of beams...
Kim, Jongheon
2013-01-01
An- alytical Methods in Geomechanics, 31(2):239–259. DvorkinAnalytical Methods in Geomechanics, 28:609–632. Oliver J,and Analytical Methods in Geomechanics, 2:99–128. Ventura G,
A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors
Jüngel, Ansgar
Analisi Numerica, C.N.R., Via Ferrata 1, 27100 Pavia, Italy, e-mail: pietra@dragon.ian.pv.cnr.it. Abstract-transport equations in two space dimensions. More precisely, we adopt the #12;nite-element scheme, proposed by Marini
Mixed-mode fracture of orthotropic functionally graded materials using finite elements and the
Paulino, Glaucio H.
coordinates, which are integrated into the element stiffness matrix using the isoparametric concept graded materials (FGMs) are special composites in which the volume fraction of constituent materials vary functionally graded ceramic/metal coatings have also been investigated under mechanical and thermal loads using
A new Cement to Glue non-conforming Grids with Robin interface conditions: the finite element case
Japhet, Caroline; Nataf, Frédéric
2007-01-01
We design and analyze a new non-conforming domain decomposition method based on Schwarz type approaches that allows for the use of Robin interface conditions on non-conforming grids. The method is proven to be well posed, and the iterative solver to converge. The error analysis is performed in 2D piecewise polynomials of low and high order and extended in 3D for $P_1$ elements. Numerical results in 2D illustrate the new method.
Parallel hp-Finite Element Simulations of 3D Resistivity Logging Instruments
Torres-Verdín, Carlos
Methods in Metallurgy AGH University of Science and Technology Abstract We simulate electromagnetic (EM
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING
Paris-Sud XI, Université de
FINITE WAVELET DOMAIN METHOD FOR EFFICIENT MODELING OF LAMB WAVE BASED STRUCTURAL HEALTH MONITORING of innovative Structural Health Monitoring (SHM) methods and systems. Of particular importance is the design European Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France Copyright
A MULTILEVEL METHOD FOR FINITE VOLUME DISCRETIZATION OF THE TWO-DIMENSIONAL NONLINEAR SHALLOW-WATER
Temam, Roger
shallow-water equations. The multilevel method is based on a central-upwind finite volume scheme and uses new incremental unknowns which enable to preserve the numerical conservation of the scheme. The method originally developed for the study of turbulent flows ([8], [9], [10], [19], [20]) but can be of interest
Kim, Jongheon
2013-01-01
in statics and dy- namics,” Computational Mechanics, 40(3):static and locading conditions,” Computer Methods in Applied Mechanics and
De Castro, Carlos Armando
2011-01-01
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.
Damage Identification of a Composite Beam Using Finite Element Model Updating
Moaveni, Babak; He, Xianfei; Conte, Joel P; De Callafon, Raymond A.
2008-01-01
Shevitz, D. W. (1996), Damage identification in structuresreview of vibration-based damage identification methods, TheM. , & Samman, M. M. (1991), Damage detection from changes
Higher-Order, Space-Time Adaptive Finite Volume Methods: Algorithms, Analysis and Applications
Minion, Michael
2014-04-29
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.
Frey, Pascal
to their high mechan- ical properties leads to develop adequate design and analysis methods and especially standard tensile and bias tests is straightforward. A set of elementary tests and mono and multi. Nevertheless these methods have major drawbacks. They account neither for the mechanical behaviour
Linker, K.L.; Rawlinson, K.S.; Smith, G.
1991-10-01
The Department of Energy`s Solar Thermal Program has as one of its program elements the development and evaluation of conversion device technologies applicable to dish-electric systems. The primary research and development combines a conversion device (heat engine), solar receiver, and generator mounted at the focus of a parabolic dish concentrator. The Stirling-cycle heat engine was identified as the conversion device for dish-electric with the most potential for meeting the program`s goals for efficiency, reliability, and installed cost. To advance the technology toward commercialization, Sandia National Laboratories has acquired a Stirling Thermal Motors, Inc., kinematic Stirling engine, STM4-120, for evaluation. The engine is being bench-tested at Sandia`s Engine Test Facility and will be combined later with a solar receiver for on-sun evaluation. This report presents the engine characteristics, finite element analyses of critical engine components, test system layout, instrumentation, and preliminary performance results from the bench test.
Optimal convergence analysis for the eXtended Finite Element Serge Nicaise 1
Renard, Yves - PÃ´le de MathÃ©matiques, Institut National des Sciences AppliquÃ©es de Lyon
.Renard@insa-lyon.fr 3 Laboratory for Nuclear Materials, Nuclear Energy and Safety Research Department, Paul Scherrer contribution of Xfem. Another classical method to take into account a singular behavior of the solution
Hoffman, E.L.; Ammerman, D.J.
1995-04-01
A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. During the pulse buckling tests, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. Numerical simulations of the test were performed using PRONTO, a Sandia developed transient dynamics analysis code, and ABAQUS/Explicit with both shell and continuum elements. The calculations are compared to the tests with respect to deformed shape and impact load history.
Berry, R. Stephen
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
FINITE VOLUME METHODS APPLIED TO THE COMPUTATIONAL MODELLING OF WELDING PHENOMENA
Taylor, Gary
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
Gas-Kinetic Finite Volume Methods K. Xu, L. Martinelli, A. Jameson
Jameson, Antony
Gas-Kinetic Finite Volume Methods K. Xu, L. Martinelli, A. Jameson Department of M.A.E, Princeton University, Prificeton N.J. 08544, USA 1 Introduction Gas-kinetic schemes developed from the BGK model have been successfully applied to 1-D and 2-D flows [1,2]. One of the advantages of the gas-kinetic approach
An accurate and robust finite volume method for the advection diffusion equation
Vuik, Kees
;Chapter 1 Introduction At present, plans are being made for the construction of Liquefied Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.2 Water quality order schemes . . . . . . . . . . . . . . . . . . . . 15 3.3 Finite volume method for the water quality
A MT System from Turkmen to Turkish Employing Finite State and Statistical Methods
Yanikoglu, Berrin
between close language pairs can be relatively easier and can still benefit from simple(r) paradigms in MT with a disambiguation post-processing stage based on statistical language models. The very productive inflectionalA MT System from Turkmen to Turkish Employing Finite State and Statistical Methods A. Cüneyd TANTU
BILAYER PLATES: MODEL REDUCTION, -CONVERGENT FINITE ELEMENT APPROXIMATION AND DISCRETE GRADIENT FLOW
Bonito, Andrea
by the deformation as in the case of the bending of a piece of paper. A related numerical method has been devised for the practical computation of large bilayer bending deformations. Our contributions in this paper are FLOW SÂ¨OREN BARTELS, ANDREA BONITO , AND RICARDO H. NOCHETTO Abstract. The bending of bilayer plates
Finite element modeling of long-term fluid-structure interaction problems in geological media
Anderson, C.A.
1980-01-01
A model is developed to predict long-term thermal creep and creep rupture in geological structures under multiaxial stress states and under elevated temperature conditions. An example of the method is given showing the behavior of the crust and mantle while undergoing intrusion by a low density diaper. (ACR)
Finite element study of multi-modal vibration damping for thermal barrier coating applications
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
A top quark mass measurement using a matrix element method
Linacre, Jacob Thomas; /Oxford U.
2010-02-01
A measurement of the mass of the top quark is presented, using top-antitop pair (t{bar t}) candidate events for the lepton+jets decay channel. The measurement makes use of Tevatron p{bar p} collision data at centre-of-mass energy {radical}s = 1.96 TeV, collected at the CDF detector. The top quark mass is measured by employing an unbinned maximum likelihood method where the event probability density functions are calculated using signal (t{bar t}) and background (W+jets) matrix elements, as well as a set of parameterised jet-to-parton mapping functions. The likelihood function is maximised with respect to the top quark mass, the fraction of signal events, and a correction to the jet energy scale (JES) of the calorimeter jets. The simultaneous measurement of the JES correction ({Delta}{sub JES}) provides an in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using 578 lepton+jets candidate events corresponding to 3.2 fb{sup -1} of integrated luminosity, the top quark mass is measured to be m{sub t} = 172.4 {+-} 1.4 (stat+{Delta}{sub JES}) {+-} 1.3 (syst) GeV=c{sup 2}, one of the most precise single measurements to date.
A fast multipole boundary element method for solving the thin plate bending problem
Liu, Yijun
in this paper. The method is based on the Kirchhoff thin plate bending theory and the biharmonic equationA fast multipole boundary element method for solving the thin plate bending problem S. Huang, Y: Fast multipole method Boundary element method Thin plate bending problem a b s t r a c t A fast
Cambridge, University of
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
King, Joshua David
2005-02-17
are produced as a result of interaction of the transmitter generated primary fields with the seawater and subsurface. Badea et al. (2001) coded an existing algorithm for solving Maxwell?s equations. This finite element 3D forward modeling algorithm is used...
Wavelet-finite element bases for numerical solutions of partial differential equations
Strader, Roy Arlen
1996-01-01
Coefficients 3. 7 Computation of Right Hand Side . 3. 8 Daubechies' Wavelets 3. 9 Deficiencies of Wavelets 4 INTRODUCTION TO THE HYBRID METHOD 4. 1 Recent Work 4. 1. 1 Periodic Boundary Conditions 4. 1. 2 Truncated Wavelets . . . . . . . . . . . 4. 1. 3... s Smallest Error in Overlap 8 Diagram for Proof Page 26 30 34 34 37 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Apprmimating u = cos xx, h = 2, Scheme II Approximating u = cos ex, h = 2, Scheme II Apprmimating u = cos...
FORMULATION AND ANALYSIS OF A PARAMETER-FREE STABILIZED FINITE ELEMENT
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) |production at a linear(Conference) | SciTechMETHOD. (Journal Article)
A Massively Parallel Sparse Eigensolver for Structural Dynamics Finite Element Analysis
Day, David M.; Reese, G.M.
1999-05-01
Eigenanalysis is a critical component of structural dynamics which is essential for determinating the vibrational response of systems. This effort addresses the development of numerical algorithms associated with scalable eigensolver techniques suitable for use on massively parallel, distributed memory computers that are capable of solving large scale structural dynamics problems. An iterative Lanczos method was determined to be the best choice for the application. Scalability of the eigenproblem depends on scalability of the underlying linear solver. A multi-level solver (FETI) was selected as most promising for this component. Issues relating to heterogeneous materials, mechanisms and multipoint constraints have been examined, and the linear solver algorithm has been developed to incorporate features that result in a scalable, robust algorithm for practical structural dynamics applications. The resulting tools have been demonstrated on large problems representative of a weapon's system.
Finite element analysis of the I-40 bridge over the Rio Grande
Farrar, C.R.; Duffey, T.A.; Goldman, P.A.; Jauregui, D.V.; Vigil, J.S.
1996-01-01
In the 1960s and 1970s numerous bridges were built in the US with a design similar to those on Interstate 40 (I-40) over the Rio Grande in Albuquerque, New Mexico. The Federal Highway Administration (FHWA) and the National Science Foundation (NSF) have provided funds to New Mexico State University (NMSU) through the New Mexico State Highway and Transportation Department (NMSH and TD) and The Alliance For Transportation Research (ATR) for evaluation and testing of the existing fracture-critical bridges over the Rio Grande. Because the I-40 Bridges over the Rio Grande were to be razed during the summer of 1993, the investigators were able to introduce damage into the structure in order to test various damage identification methods and to observe the changes in load paths through the structure caused by the cracking. To support this research effort, NMSU contracted Los Alamos National Laboratory (LANL) to perform experimental modal analyses, and to develop experimentally verified numerical models of the bridge. A previous report (LA-12767-MS) summarizes the results of the experimental modal analyses. This report summarizes the numerical analyses of the bridges and compares the results of these analyses to the experimental results.
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)
2014-02-18
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.
Quinones, Armando (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei
2006-06-01
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.
Tezaur, I. K. [Sandia National Laboratories; Perego, M. [Sandia National Laboratories; Salinger, A. G. [Sandia National Laboratories; Tuminaro, R. S. [Sandia National Laboratories; Price, S. F. [Los Alamos National Laboratory
2015-01-01
This paper describes a new parallel, scalable and robust finite element based solver for the first-order Stokes momentum balance equations for ice flow. The solver, known as Albany/FELIX, is constructed using the component-based approach to building application codes, in which mature, modular libraries developed as a part of the Trilinos project are combined using abstract interfaces and template-based generic programming, resulting in a final code with access to dozens of algorithmic and advanced analysis capabilities. Following an overview of the relevant partial differential equations and boundary conditions, the numerical methods chosen to discretize the ice flow equations are described, along with their implementation. The results of several verification studies of the model accuracy are presented using (1) new test cases for simplified two-dimensional (2-D) versions of the governing equations derived using the method of manufactured solutions, and (2) canonical ice sheet modeling benchmarks. Model accuracy and convergence with respect to mesh resolution are then studied on problems involving a realistic Greenland ice sheet geometry discretized using hexahedral and tetrahedral meshes. Also explored as a part of this study is the effect of vertical mesh resolution on the solution accuracy and solver performance. The robustness and scalability of our solver on these problems is demonstrated. Lastly, we show that good scalability can be achieved by preconditioning the iterative linear solver using a new algebraic multilevel preconditioner, constructed based on the idea of semi-coarsening.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tezaur, I. K.; Perego, M.; Salinger, A. G.; Tuminaro, R. S.; Price, S. F.
2015-04-27
This paper describes a new parallel, scalable and robust finite element based solver for the first-order Stokes momentum balance equations for ice flow. The solver, known as Albany/FELIX, is constructed using the component-based approach to building application codes, in which mature, modular libraries developed as a part of the Trilinos project are combined using abstract interfaces and template-based generic programming, resulting in a final code with access to dozens of algorithmic and advanced analysis capabilities. Following an overview of the relevant partial differential equations and boundary conditions, the numerical methods chosen to discretize the ice flow equations are described, alongmore »with their implementation. The results of several verification studies of the model accuracy are presented using (1) new test cases for simplified two-dimensional (2-D) versions of the governing equations derived using the method of manufactured solutions, and (2) canonical ice sheet modeling benchmarks. Model accuracy and convergence with respect to mesh resolution are then studied on problems involving a realistic Greenland ice sheet geometry discretized using hexahedral and tetrahedral meshes. Also explored as a part of this study is the effect of vertical mesh resolution on the solution accuracy and solver performance. The robustness and scalability of our solver on these problems is demonstrated. Lastly, we show that good scalability can be achieved by preconditioning the iterative linear solver using a new algebraic multilevel preconditioner, constructed based on the idea of semi-coarsening.« less
System and method for reproducibly mounting an optical element
Eisenbies, Stephen; Haney, Steven
2005-05-31
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.
Analysis of Topological Chaos in Ghost Rod Mixing at Finite Reynolds Numbers Using Spectral Methods
Rao, Pradeep C.
2011-02-22
December 2009 Major Subject: Mechanical Engineering ANALYSIS OF TOPOLOGICAL CHAOS IN GHOST ROD MIXING AT FINITE REYNOLDS NUMBERS USING SPECTRAL METHODS A Thesis by PRADEEP CHANDRAKANT RAO Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Andrew T. Duggleby Committee Members, N. K. Anand Hamn-Ching Chen Head of Department, Dennis O?Neil December 2009 Major Subject: Mechanical...
Method for recovering catalytic elements from fuel cell membrane electrode assemblies
Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley Heights, NJ); Heinz, Robert (Ludwigshafen, DE)
2012-06-26
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.
Calisch, Samuel Eli
2014-01-01
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 ...
Abdou, Mohamed
2007-01-01
Fusion Engineering and Design 82 (2007) 22332238 Application of discrete element method to study mechanical behaviors of ceramic breeder pebble beds Zhiyong An, Alice Ying, Mohamed Abdou Mechanical In this paper, the discrete element method (DEM) approach has been applied to study mechanical behaviors
Interfacial stress analysis for multi-coating systems using an advanced boundary element method
Liu, Yijun
Interfacial stress analysis for multi-coating systems using an advanced boundary element method J for multi-coating systems using an advanced boundary element method (BEM) developed earlier in [Luo JF, Liu by the analytical solution of a special multi-coating problem. Detailed in- terfacial stress analysis for a two
Kais, Sabre
2012-01-01
results for critical parameters by using a systematic expansion with global basis-type functions. Recently initio approximations and exact formulations. The critical parameters could be atomic nuclear charges for the two-electron atom with varying nuclear charge; these include Hartree-Fock, local density approximation
Droniou, Jérôme
continuous. 9.1 Introduction The purpose of oil reservoir simulation implies to account for several phenomena for the saturation of one of the phases coupled with an elliptic equation for the pressure. Assuming the total))f + (x) - (1 - u(x, t))f - (x), for (x, t) ## ×R + . In the above equations, the saturation of the water
Raut, Ameeta A.
2010-07-14
fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, J. N. Reddy Committee Members, Ibrahim Karaman Jose Roesset Head of Department, Dennis O?Neal December 2009 Major Subject: Mechanical... of Advisory Committee: Dr. J. N. Reddy The conventional finite element models (FEM) of problems in structural mechanics are based on the principles of virtual work and the total potential energy. In these models, the secondary variables...
A ?nite element method to model attenuation and dispersion effects ...
Patricio
particular case the seismic method is ef?cient. 2 . Proposed methodology we consider a 2D isotropic ?uid—saturated porous material (I with boundary 3Q ...
Methods for making a porous nuclear fuel element
Youchison, Dennis L; Williams, Brian E; Benander, Robert E
2014-12-30
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.
Gangwal, Santosh K.; Nikolopoulos, Apostolos A.; Dorchak, Thomas P.; Dorchak, Mary Anne
2005-11-08
A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.
Bluff Body Flow Simulation Using a Vortex Element Method
Anthony Leonard; Phillippe Chatelain; Michael Rebel
2004-09-30
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.
Heuer, Norbert
, and by the Ministery of Education of Spain through the project MTM2010-18427. CI2 MA and Departamento de Ingenier was partially supported by BASAL project CMM, Universidad de Chile, by Centro de Investigaci´on en Ingenier
Calculation of eddy currents in moving structures by a sliding mesh-nite element method
Buffa, Annalisa
Calculation of eddy currents in moving structures by a sliding mesh- nite element method A. Bu of eddy currents in non-stationary structures. Both 2D and 3D models are considered. The approximation. An implicit Euler scheme is used to discretize in time. Key words { eddy currents, nite element approxima
Method for the removal of elemental mercury from a gas stream
Mendelsohn, M.H.; Huang, H.S.
1999-05-04
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.
Finite amplitude method applied to giant dipole resonance in heavy rare-earth nuclei
Oishi, Tomohiro; Hinohara, Nobuo
2016-01-01
Background: The quasiparticle random phase approximation (QRPA), within the framework of the nuclear density functional theory (DFT), has been a standard tool to access the collective excitations of the atomic nuclei. Recently, finite amplitude method (FAM) has been developed, in order to perform the QRPA calculations efficiently without any truncation on the two-quasiparticle model space. Purpose: We discuss the nuclear giant dipole resonance (GDR) in heavy rare-earth isotopes, for which the conventional matrix diagonalization of the QRPA is numerically demanding. A role of the Thomas-Reiche-Kuhn (TRK) sum rule enhancement factor, connected to the isovector effective mass, is also investigated. Methods: The electric dipole photoabsorption cross section was calculated within a parallelized FAM-QRPA scheme. We employed the Skyrme energy density functional self-consistently in the DFT calculation for the ground states and FAM-QRPA calculation for the excitations. Results: The mean GDR frequency and width are mo...
A TRACE FINITE ELEMENT METHOD FOR A CLASS OF COUPLED BULK-INTERFACE TRANSPORT PROBLEMS
Olshanskii, Maxim A.
, MAXIM A. OLSHANSKII, AND ARNOLD REUSKENÂ§ Abstract. In this paper we study a system of advection of coupled partial differential equations arise in, for example, the modeling of transport and diffusion phenomena related to soluble surfactants in two-phase incom- pressible flows we refer to the literature, e
ERROR ESTIMATES FOR A FINITE ELEMENT METHOD FOR THE DRIFT-DIFFUSION SEMICONDUCTOR DEVICE EQUATIONS
is of order ( x)1=2. This *University of Minnesota Army High Performance Computing Research Center, 1100 Foundation grant DSM-9103997 and by the University of Minnesota Army High Performance Computing Research
Space-Time Discontinuous Galerkin Finite Element Method for Two-Fluid Flows.
Al Hanbali, Ahmad
flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed columns, fluidized beds, granular flows and ink spraying. The flow patterns in these problems are complex evolution, Rayleigh-Taylor and Kelvin-Helmholtz instabil- ities and industrial processes such as bubble
Two Fluid Space-Time Discontinuous Galerkin Finite Element Method. Part I: Numerical Algorithm
Al Hanbali, Ahmad
-Taylor and Kelvin-Helmholtz instabil- ities and industrial processes such as bubble columns, fluidized beds, liquids and solids and have many applications in nature and industry. Examples include flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed evolution, Rayleigh
Ng, Chi Kin
1978-01-01
loading cond1t1ons are presented and compared witn exact solutions. ACKNOWLEDGMENTS The author wishes to express his sincere gratitude and appreciation to Dr. Jack Y. K, Lou, Associate Professor of Civil Engineering, Texas AiiM University, for his time... Concent. rated Load of 2000 lbs. with a Forcing Frequence of 40 c. p. s. at Apex. 34 Radial Displacement Due to a Concentrated Load of 2000 lbs. with a Forcing Frequency of 240 c. p. s. at Apex . v 1 i NOMENCLATURE AM C(Sx) CD GP GQ radius...
Adaptive Discontinuous Galerkin Finite Element Methods with Interior Penalty for the Compressible
Hartmann, Ralf
Navier{Stokes Equations Ralf Hartmann 1 and Paul Houston 2 1 Institute of Aerodynamics and Flow Technology, German Aerospace Center, Lilienthalplatz 7, 38108 Braunschweig, Germany. Email: Ralf.Hartmann ] T and #12; 2 Hartmann and Houston f v i = [0; #28; 1i ; #28; 2i ; #28; i1 v 1 + #28; i2 v 2 +KT x i
Adaptive Discontinuous Galerkin Finite Element Methods for the Compressible Euler Equations
Hartmann, Ralf
Hartmann Institute of Applied Mathematics, University of Heidelberg, Im Neuenheimer Feld 293, D-69120 Heidelberg, Germany (e-mail: Ralf.Hartmann@iwr.uni-heidelberg.de). and Paul Houston Department of Mathematics-dimensional problems with guaranteed error control. While for problems arising in solid me- 1 #12; 2 HARTMANN
Analysis of finite element approximation and iterative methods for time-dependent Maxwell problems
Zhao, Jun
2004-09-30
naturally transfer (2.20) to the semi-discrete scheme of seeking (Eh(t);Bh(t)) in Uh Vh satisfying, for any 0 Eh;t;uh) ( 1Bh;curluh) = (J;uh); for all uh 2 Uh; ( 1Bh;t;vh) + (curlEh; 1vh) = 0; for all vh 2 Vh; (2.21) 19 with given initial... approximations Eh(0) E0 and Eh(0) E0: (2.22) We will discuss possible choices of initial approximations in the following chapter. When we try to discretize time derivatives in (2.21), the stability of the resulting fully discrete scheme critically depends...
Code verification for the eXtended Finite Element Method (XFEM...
Office of Scientific and Technical Information (OSTI)
Resource Type: Conference Resource Relation: Conference: DoD High Performance Computing Modernization Program 21st Users Group Conference held June 20-23, 2011 in...
FINITE ELEMENT METHODS: 1970's AND BEYOND L.P. Franca (Ed.)
Masud, Arif
of Colorado at Denver P.O. Box 173364, Campus Box 170 Denver, CO 80217-3364, USA Departamento de Mecanica de
Ritz-Volterra Reconstructions and A Posteriori Error Analysis of Finite Element Method for Parabolic
Ewing, Richard E.
conduction in material with memory [10], the compression of poro-viscoelasticity media [11], nuclear reactor meshing procedures de- signed to control and minimize the error. Over the last two decades, a posteriori
Lee, Sang Hoon
2012-02-14
Stress and permeability variations around a wellbore and in the reservoir are of much interest in petroleum and geothermal reservoir development. Water injection causes significant changes in pore pressure, temperature, ...
A P 1 \\Gamma P 0 FINITE ELEMENT METHOD FOR A MODEL OF POLYMER CRYSTALLIZATION*
Nochetto, Ricardo H.
-posedness theorem. © 2008 Elsevier Inc. All rights reserved. MSC: 76A10; 35L80; 35A05; 35B45; 35B50; 80A22 Keywords
An adaptive least squares mixed finite element method for the stress ...
2004-10-19
Contract grant sponsor: Deutsche Forschungsgemeinschaft (DFG); contract grant number: STA 402/8 (to J.K.). © 2004 Wiley Periodicals, Inc.
Nguyen, Hieu Trung
2010-01-01
Assistant, San Diego Super Computer Center PUBLICATIONS R.assistant at San Diego Super Computer Center in the summer
Stent design and arterial mechanics: parameterization tools using the finite element method
Bedoya Cervera, Jose Julian
2007-09-17
Vascular stents are medical devices used to treat stenoses blockages in arteries that restrict blood flow. Most commonly, stents are made out of stainless steel or nitinol, and are delivered to the afflicted sites via ...
Code verification for the eXtended Finite Element Method (XFEM): the
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (TechnicalTransmission,TextitSciTechinRequirementsor Heat1.10Report)compound
An Implementation of the Generalized Finite Element Method for Large Scale
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation4563AbuseConnect Technicalof PDEs with(Conference) |
Partition-of-unity finite-element method for large scale quantum molecular
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech ConnectSpeeding access to(Conference) |ofPDVGLENELG(JournalShallowreactionsArticle)
Partition-of-unity finite-element method for large scale quantum molecular
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech ConnectSpeeding access to(Conference)
The generalized finite element method applied to the dynamic response of
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)FeedbackProperties ofTheatmosphereSouthern OceanandIII star
Extending the Matrix Element Method to Next-to-Leading Order
John M. Campbell; Walter T. Giele; Ciaran Williams
2012-05-15
We discuss the extension of the matrix element method (MEM) to Next-to-Leading Order (NLO) in perturbation theory. In particular we focus on the production of a Standard Model Higgs boson which decays into four leptons.
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter ByMentor-ProtegeFromGasInnovationMethod for Detecting
Apparatus for and method of monitoring for breached fuel elements
Gross, Kenny C. (Lemont, IL); Strain, Robert V. (Woodbridge, IL)
1983-01-01
This invention teaches improved apparatus for the method of detecting a breach in cladded fuel used in a nuclear reactor. The detector apparatus uses a separate bypass loop for conveying part of the reactor coolant away from the core, and at least three separate delayed-neutron detectors mounted proximate this detector loop. The detectors are spaced apart so that the coolant flow time from the core to each detector is different, and these differences are known. The delayed-neutron activity at the detectors is a function of the dealy time after the reaction in the fuel until the coolant carrying the delayed-neutron emitter passes the respective detector. This time delay is broken down into separate components including an isotopic holdup time required for the emitter to move through the fuel from the reaction to the coolant at the breach, and two transit times required for the emitter now in the coolant to flow from the breach to the detector loop and then via the loop to the detector. At least two of these time components are determined during calibrated operation of the reactor. Thereafter during normal reactor operation, repeated comparisons are made by the method of regression approximation of the third time component for the best-fit line correlating measured delayed-neutron activity against activity that is approximated according to specific equations. The equations use these time-delay components and known parameter values of the fuel and of the part and emitting daughter isotopes.