Modeling of void coalescence initiation and its impact on the prediction of material failure

Abstract

In the present paper, Thomason’s criterion is coupled with the well-known Gurson–Tvergaard–Needleman (GTN) damage model and used for the determination of the critical void volume fraction fc , which marks the initiation of the coalescence stage. The onset of void coalescence predicted by Thomason’s criterion is compared to that obtained by using a predefined fc , which is usually fitted on the basis of experimental results, as originally proposed in the GTN model. Comparisons are made in terms of both single finite element simulations and numerical results of deep drawing of a cup.