Finite element modelling of anisotropic elastic-viscoplastic behaviour of metals

An implementation of the unified theory of visco-plasticity of Bodner in a three-dimensional finite element program for the analysis of anisotropic in elastic behaviour of selected metals is presented in this paper. A derivati on of an effective hardening parameter for the anisotropic (directional) de formation state is also given in this paper using some basic assumptions in troduced by Bodner. The effect of the imposed strain rate on the level of t he stress-strain curve is also investigated. A comparison of the results of the present finite element model with some published theoretical and exper imental results for pure titanium and 2024-T4 aluminium alloy is also made. (C) 1999 Elsevier Science B.V. All rights reserved.