Numerical simulation of elastoplastic behavior and damage evolution of metals at various stress triaxialities

The theory of continuum damage mechanics with a phenomenological approach is used in predicting the phenomenon of material failure, and since each material has its own behavior, it is especially important to find out the damage behavior of common used metals. In this study, the constants of two damage models, Ganjiani and Bonora, for analyzing the elastoplastic damage behavior of several metals by writing VUMAT subroutine in Abaqus software, simulation and comparison with experimental data in literature, were determined and the ability and efficiency of models in the analysis of metals damage behavior was ensured. In finding the constants of the models, stress-strain, damage-strain and failures train-stress triaxiality diagrams were used and after the simulation, with the help of force-displacement diagram, which had a good agreement with the experimental diagram for each metal, the accuracy of the performance was confirmed. In general, the constants during a trial and error process were determined to be the optimal fit. The studied metals were steel 1045, aluminum 2024-T351and HY130 steel. For the first two metals, only simple tension test is simulated, and for HY130 steel a more general test, three point bending test, is simulated and the obtained force-displacement diagram was compared with the experimental diagram. Also, because the strains were in the range of large strains, the relationships related to large strains have been used.