Influence of material modeling on simulation accuracy of aluminum stampings

The best practice in modeling material yield, strain hardening and anisotropic behavior in plastic deformation has been analyzed for an AA 6016 aluminum alloy. The investigation was based on the extensive material property testing, stamping benchmarking and AutoForm simulations. For the material property testing, both the uniaxial tensile test and the hydraulic bulge test were conducted. The elliptic punch test and the cross die test served as the benchmarks to validate the simulation results. In the simulations, the material characteristics was modeled with the combinations of four strain-hardening models and three yield criteria. By comparing the simulation results with the experimental measurements, the influence of material modeling on aluminum stamping simulation accuracy was evaluated. It was concluded from this study that the yield criterion is the key factor in controlling the simulation accuracy. The simulation with the BBC2005 yield model predicts the most accurate results. It was also shown that the combined Swift/Hockett-Sherby strain-hardening model is most suitable to describe aluminum strain hardening behavior.