Improvements for finite-element implementation of the Gurson Model

In this contribution three modifications for the plastic potential of the Gurson model are proposed, which give, from the numerical point of view, some improvements for the finite-element implementation. Firstly a linear representation is used, which shows superior convergence property in the local iteration procedure compared to the original quadratic representation. Furthermore the cosh-function appearing in the original formulation is replaced by a modified Cosh-function, thus avoiding the overflow effect in the local iteration procedure for in-between values. Additionally a smoothing technique is applied to the modified void volume function f*[f] introduced by TVERGAARD & NEEDLEMAN [3]. A numerical example illustrates the advantage of the proposed approach.