Aspects on the finite-element implementation of the Gurson model including parameter 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 property in the local iteration procedure compared to the original quadratic representation. The formulation of the model is performed in the spatial configuration based on the multiplicative decomposition of the deformation gradient, and for integration an exponential map scheme is used. A further important aspect is the sensitivity analysis consistent with the underlying integration scheme necessary for minimizing a least-squares functional for parameter identification by use of a gradient-based optimization algorithm. In a numerical example the local convergence behavior for the two versions of the Gurson model, linear and quadratic are compared. Furthermore material parameters are determined by least-squares minimization based on experimental data obtained for an axisymmetric tensile bar for a ferritic steel. (C) 1999 Elsevier Science Ltd. All rights reserved.