FE computation of a triaxial specimen using a polycrystalline model

The crystallographic approach provides an improved framework with respect to the classical macroscopic models to predict the stress-strain behavior of polycrystalline material, The model consists in a set of equations to represent the phase behavior, and a concentration rule. The present paper shows a numerical implementation of such a model, written in the framework of viscoplasticity with a threshold, in a parallel version of the F.E. code ZeBuLoN. Heavy computations can then be made. The system is used to simulate the mechanical response of a biaxial specimen developed at Laboratoire de Mecanique et Technologie de Cachan. This type of specimen is specially designed to support three-dimensional non-proportional loading paths, which are badly represented by classical models. The response obtained with the polycrystalline model is shown, and compared with the experimental data at the global scale, Local information concerning the stress and strain heterogeneity and the slip system activity are also available from the computation. (C) 1997 Elsevier Science B.V.