Constitutive model for the elastic-plastic analysis of porous sintered materials

It is a known fact that it is very difficult to implement the algorithm of plasticity of porous materials in FEM commercial programs for different types and characteristics. The aim of this paper is to put forward a flexible model of plasticity of porous materials by implementing it into the general purpose finite element program ABAQUS(R). A modified algorithm is developed in this paper which takes into account the effect of an isotropic work hardening of the porous material. This is incorporated into the FEM program to yield a flexible solution for different yielding criterion. The present criterion is compared with other known published work and was found to be in good agreement. It was found that all the failure criteria used were successfully implemented using the newly developed algorithm. Also, the present criterion is adequately adjusted to fit all other results obtained from other criteria of failure. Finally, some of these published criteria had not been implemented previously for use in the FEM programs, but in this paper were made to do so. Other theoretical results will also be presented. (C) 2004 Elsevier Ltd. All rights reserved.