Aspects on the finite-element implementation of the Gurson model includingparameter identification

In this contribution, various aspects on the finite-element implementation of the Gurson model are considered. In particular, a linear representation for the plastic potential is used, which shows superior convergence propert y in the local iteration procedure compared to the original quadratic repre sentation. The formulation of the model is performed in the spatial configu ration based on the multiplicative decomposition of the deformation gradien t, and for integration an exponential map scheme is used. A further importa nt aspect is the sensitivity analysis consistent with the underlying integr ation scheme necessary for minimizing a least-squares functional for parame ter identification by use of a gradient-based optimization algorithm. In a numerical example the local convergence behavior for the two versions of th e Gurson model, linear and quadratic are compared. Furthermore material par ameters are determined by least-squares minimization based on experimental data obtained for an axisymmetric tensile bar for a ferritic steel. (C) 199 9 Elsevier Science Ltd. All rights reserved.