A Study of the Gurson Damage Model and Numerical Simulation of Ductile Failure in LS-DYNA

Standard material models like linear elastic or elastic plastic formulations are not able to precisely reproduce component behavior when failure occurs. Micromechanical damage models enable a more accurate prediction of material behavior, but still require expert knowledge. In the presented study, the capability of the simple piecewise linear plasticity and the Gurson-Tvergaard-Needleman material model to accurately reproduce and predict physical failure behavior is examined. The main focus is to investigate the capabilities to reproduce stress state and crack growth in a physically meaningful way. Mesh size and material formulation effects are studied on single edge bending and notched tensile specimens. The results obtained from the different simulations with the GTN model and the piecewise linear plasticity model are compared for conventional finite element simulations and the element-free Galerkin method. Simulations of asymmetric crack growth show that especially the element-free Galerkin method in conjunction with the GTN model provides a powerful tool to simulate failure. With these insights, the accuracy of crash and other failure-related simulations can be improved.

application/pdf B-III-01.pdf — 1.6 MB