Prediction of shear fracture in multi-stage deep drawing process including ironing process for Al3003 sheet

To predict fracture caused by both tensile and shearing stresses, we applied the GISSMO (generalized incremental stress state-dependent model) in conjunction with the TFD (triaxiality failure diagram) in the finite element (FE) software LS-DYNA. Required damage parameters were determined by fitting to the load-displacement curves from tensile tests necessary to set up the TFD those obtained by corresponding FE analyses. Curve fitting was performed using the optimum design tool LS-OPT. For validation, the obtained GISSMO damage parameters were applied to the problem of rectangular cup forming for Al3003 material. Good agreement between the numerically obtained fracture locus and that observed in real forming shows that accurate shear fracture prediction is possible with the presented GISSMO-based approach.