Research on WALKER Constitutive Model Tangent Modulus

2012 ◽  
Vol 249-250 ◽  
pp. 113-117
Author(s):  
Yan Chen ◽  
Qing Wu Wang ◽  
Quan Shan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Constitutive Model ◽  
Constitutive Equations ◽  
Tangent Modulus ◽  
Finite Element Code ◽  
Numerical Examples ◽  
Rate Dependent ◽  
Backward Euler ◽  
Elasto Plasticity

In elasto-plasticity computation on materials by sub-increase finite element method, in general, it is necessary to calculate the consistent tangent modulus of elements. In this paper, based on the backward Euler integration, for an unified viscoplasticity constitutive equations, a new expression of consistent tangent modulus is derived for rate-dependent plasticity. The constitutive equations and consistent tangent modulus expression are implemented into a commercial finite element code-MARC. Numerical examples are given to verify the finite element implementation.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Thermo-Elastoviscoplastic Buckling Behavior of Plates

1994 ◽  
Vol 61 (1) ◽  
pp. 169-175 ◽  
Author(s):  
G. J. Simitses ◽  
Y. Song
Keyword(s):  
Finite Element ◽  
Constitutive Equations ◽  
Material Models ◽  
Inelastic Buckling ◽  
Finite Element Approach ◽  
Numerical Examples ◽  
Initial Imperfections ◽  
Rate Dependent ◽  
Buckling Behavior ◽  
Element Approach

The thermo-elastoviscoplastic buckling behavior of plates is investigated. The analysis is based on nonlinear kinematic relations and nonlinear rate-dependent unified constitutive equations which include both Bodner-Partom’s and Walker’s material models. A finite element approach is employed to predict the inelastic buckling behavior. Numerical examples are given to demonstrate the effects of several parameters, which include temperature, small initial imperfections, and the thickness of the plate. Comparisons of buckling responses for the two models, Bodner-Partom’s and Walker’s, are also presented.

Constitutive Model of Solid Propellant with Mechanical Damage and Aging

2012 ◽  
Vol 198-199 ◽  
pp. 197-201 ◽  
Author(s):  
Xiao Jun Zhang ◽  
Xin Long Chang ◽  
Shi Ying Zhang ◽  
Shun Xiang Chen ◽  
Jie Tang Zhu
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Constitutive Equations ◽  
Solid Propellant ◽  
Damage Mechanics ◽  
Engineering Application ◽  
Mechanical Damage ◽  
Finite Element Code ◽  
Nonlinear Characteristics

Mechanical damage and aging are the main mechanisms of nonlinear characteristics of solid propellant.A comprehensive big strain visco-elastic constitutive model with damage mechanics and aging was established, by using the visco-elastic constitutive equations form expressed by the generalized variable, introducing damage variables, and taking the relaxation modules after aging to characterize the aging. The correctness of the model was verified through experiments. the parameters need by modeling are easy to be got, and converted into the finite element code to do the simulation computation, then the model is suitable for the engineering application.

scholarly journals Efficient Galerkin finite element methods for a time-fractional Cattaneo equation

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
An Chen ◽  
Lijuan Nong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Galerkin Finite Element Method ◽  
Galerkin Finite Element ◽  
Numerical Examples ◽  
Fully Discrete ◽  
Backward Euler ◽  
Galerkin Finite Element Methods ◽  
Difference Methods ◽  
Fractional Cattaneo Equation

Abstract In this paper, we develop two efficient fully discrete schemes for solving the time-fractional Cattaneo equation, where the fractional derivative is in the Caputo sense with order in $(1, 2]$ ( 1 , 2 ] . The schemes are based on the Galerkin finite element method in space and convolution quadrature in time generated by the backward Euler and the second-order backward difference methods. Error estimates are established with respect to data regularity. We further compare our schemes with the L2-$1_{\sigma }$ 1 σ scheme. Numerical examples are provided to show the efficiency of the schemes.

The Equilibrium Cell-Based Smooth Finite Element Method for Shakedown Analysis of Structures

2019 ◽  
Vol 16 (05) ◽  
pp. 1840013 ◽  
Author(s):  
P. L. H. Ho ◽  
C. V. Le ◽  
T. Q. Chu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Optimization Problem ◽  
Conic Programming ◽  
Equilibrium Equations ◽  
Shakedown Analysis ◽  
Numerical Examples ◽  
Elastic Stresses ◽  
Gauss Points ◽  
Element Method

This paper presents a novel equilibrium formulation, that uses the cell-based smoothed method and conic programming, for limit and shakedown analysis of structures. The virtual strains are computed using straining cell-based smoothing technique based on elements of discretized mesh. Fictitious elastic stresses are also determined within the framework of finite element method (CS-FEM)-based Galerkin procedure, and equilibrium equations for residual stresses are satisfied in an average sense at every cell-based smoothing cell. All constrains are imposed at only one point in the smoothing domains, instead of Gauss points as in a standard FEM-based procedure. The resulting optimization problem is then handled using the highly efficient solvers. Various numerical examples are investigated, and obtained solutions are compared with available results in the literature.

Hot Forging Comparative Analyses by Using a Combined Finite Element Method

2007 ◽  
Vol 340-341 ◽  
pp. 737-742
Author(s):  
Yong Ming Guo
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Hot Forging ◽  
Rigid Plastic ◽  
Numerical Examples ◽  
Comparative Analyses ◽  
Single Action ◽  
Element Method

In this paper, single action die and double action die hot forging problems are analyzed by a combined FEM, which consists of the volumetrically elastic and deviatorically rigid-plastic FEM and the heat transfer FEM. The volumetrically elastic and deviatorically rigid-plastic FEM has some merits in comparison with the conventional rigid-plastic FEMs. Differences of calculated results for the two forging processes can be clearly seen in this paper. It is also verified that these calculated results are similar to those of the conventional rigid-plastic FEM in comparison with analyses of the same numerical examples by the penalty rigid-plastic FEM.

scholarly journals A Numerical Solution to Fractional Diffusion Equation for Force-Free Case

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
O. Tasbozan ◽  
A. Esen ◽  
N. M. Yagmurlu ◽  
Y. Ucar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Diffusion Equation ◽  
Exact Analytical Solution ◽  
Fractional Diffusion ◽  
Fractional Diffusion Equation ◽  
Spline Functions ◽  
B Spline ◽  
Numerical Examples ◽  
Free Case

A collocation finite element method for solving fractional diffusion equation for force-free case is considered. In this paper, we develop an approximation method based on collocation finite elements by cubic B-spline functions to solve fractional diffusion equation for force-free case formulated with Riemann-Liouville operator. Some numerical examples of interest are provided to show the accuracy of the method. A comparison between exact analytical solution and a numerical one has been made.

The Flow of UCM and Oldroyd-B Fluids Past a Cylinder

2000 ◽  
Author(s):  
Manuel A. Alves ◽  
Fernando T. Pinho ◽  
Paulo J. Oliveira
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Resolution ◽  
Constitutive Equations ◽  
Numerical Procedure ◽  
Plane Flow ◽  
Dependent Variables ◽  
High Resolution Schemes ◽  
Structured Meshes ◽  
Volume Method

Abstract Accurate solutions are obtained with the numerical method of Oliveira et al (1998) for the inertialess plane flow around a confined cylinder. This numerical procedure is based on the finite-volume method in non-orthogonal block-structured meshes with a collocated arrangement of the dependent variables, and makes use of a special interpolation practice to avoid stress-velocity decoupling. Two high-resolution schemes are implemented to represent the convective terms in the constitutive equations for the upper converted Maxwell and Oldroyd-B fluids, and the resulting predictions of the drag coefficient on the cylinder are shown to be as accurate as existing finite-element method predictions based on the very accurate h-p refinement technique.

scholarly journals Local Elastic and Geometric Stiffness Matrices for the Shell Element Applied in cFEM

2017 ◽  
Author(s):  
Dávid Visy ◽  
Sándor Ádány
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Element ◽  
Numerical Examples ◽  
Geometric Stiffness ◽  
Stiffness Matrices ◽  
Plane Element ◽  
Unusual Combination ◽  
Shell Finite Element ◽  
Lagrange Strain

In this paper local elastic and geometric stiffness matrices of ashell finite element are presented and discussed. The shell finiteelement is a rectangular plane element, specifically designedfor the so-called constrained finite element method. One of themost notable features of the proposed shell finite element isthat two perpendicular (in-plane) directions are distinguished,which is resulted in an unusual combination of otherwise classicshape functions. An important speciality of the derived stiffnessmatrices is that various options are considered, whichallows the user to decide how to consider the through-thicknessstress-strain distributions, as well as which second-order strainterms to consider from the Green-Lagrange strain matrix. Thederivations of the stiffness matrices are briefly summarizedthen numerical examples are provided. The numerical examplesillustrate the effect of the various options, as well as theyare used to prove the correctness of the proposed shell elementand of the completed derivations.

scholarly journals Elasto - plastic analysis of anisotropic hardening materials by finite element method

1985 ◽  
Vol 7 (1) ◽  
pp. 8-13
Author(s):  
Tran Duong Hien
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Program ◽  
Yield Criterion ◽  
Element Model ◽  
Isotropic Hardening ◽  
Anisotropic Hardening ◽  
Numerical Examples ◽  
Plastic Analysis ◽  
Hill's Yield Criterion

An elasto- plastic analysis for general three dimes10nal problems using a finite element model is presented. The analysis is based on Hill's yield criterion which included anisotropic materials displaying kinematic - isotropic hardening. The validity and practical applicability of the algorithm are illustrated by a number of numerical examples, calculated by a computer program written in fortran.

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