ADAPTIVE SIMULATION OF ELASTIC-PLASTIC FRACTURE PROCESSES

This works presents a methodology for numerical simulation of elastic-plastic fracture processes based on an adaptive finite element analysis. The proposed methodology is implemented in an interactive graphics computational system for two-dimensional finite element analysis, which integrates modeling, analysis, and visualization capabilities. The system is under development and its main objectives are: (a) To characterize the non-linear process zone of a crack; (b) To implement numerical procedures for computing J-integral, tearing modulus, and CTOD (Crack-tip Opening Displacement) fracturing parameters; and (c) To simulate fracture propagation based on the computed parameters and on material resistance parameters such as the JR resistance curve. The self-adaptive strategy is based on recursive spatial enumeration techniques: a binary tree partition for the boundary and the crack-line curves and a quadtree partition for domain mesh generation. Cracks can be introduced arbitrarily by the user at any position in the model. The system regenerates the meshes automatically taking into account the new created crack surfaces. The self-adaptive procedure takes into account the arbitrarily generated crack geometry and the finite element error estimation analysis. Tereza Denyse de Araújo, Deane Roehl, Túlio N. Bittencourt, and Luiz F. Martha.

[1]  James K. Knowles,et al.  On a class of conservation laws in linearized and finite elastostatics , 1972 .

[2]  R. D. Henshell,et al.  CRACK TIP FINITE ELEMENTS ARE UNNECESSARY , 1975 .

[3]  Paul A. Wawrzynek,et al.  Quasi-automatic simulation of crack propagation for 2D LEFM problems , 1996 .

[4]  H. D. Bui,et al.  Associated path independent J-integrals for separating mixed modes , 1983 .

[5]  Klaus-Jürgen Bathe,et al.  Error indicators and adaptive remeshing in large deformation finite element analysis , 1994 .

[6]  Satya N. Atluri,et al.  Path-independent integrals in finite elasticity and inelasticity, with body forces, inertia, and arbitrary crack-face conditions , 1982 .

[7]  Leslie Banks-Sills,et al.  Comparison of methods for calculating stress intensity factors with quarter-point elements , 1986 .

[8]  J. Z. Zhu,et al.  The superconvergent patch recovery and a posteriori error estimates. Part 1: The recovery technique , 1992 .

[9]  O. C. Zienkiewicz,et al.  A simple error estimator and adaptive procedure for practical engineerng analysis , 1987 .

[10]  R. Barsoum.  On the use of isoparametric finite elements in linear fracture mechanics , 1976 .

[11]  Harold Liebowitz,et al.  Examples of adaptive FEA in plasticity , 1995 .

[12]  J. Rice.  A path-independent integral and the approximate analysis of strain , 1968 .

[13]  P. Ladevèze,et al.  ERROR ESTIMATION AND ADAPTIVITY IN ELASTOPLASTICITY , 1996 .

[14]  Michael Ian Shamos,et al.  Computational geometry: an introduction , 1985 .

[15]  K. R. Grice,et al.  Robust, geometrically based, automatic two‐dimensional mesh generation , 1987 .

[16]  Luiz Fernando Martha,et al.  Adaptive simulation of fracture processes based on spatial enumeration techniques , 1997 .

[17]  R. Barsoum.  Triangular quarter‐point elements as elastic and perfectly‐plastic crack tip elements , 1977 .

[18]  Paul A. Wawrzynek,et al.  Interactive finite element analysis of fracture processes: An integrated approach , 1987 .

[19]  S. Atluri,et al.  CALCULATION OF FRACTURE MECHANICS PARAMETERS FOR AN ARBITRARY THREE-DIMENSIONAL CRACK, BY THE ‘EQUIVALENT DOMAIN INTEGRAL’ METHOD , 1987 .