Fracture Prediction for Crashworthiness Assessment of Aluminum Bumper Systems

Alcan relies strongly on crashworthiness simulations in its development of light weight automotive crash management systems at Gottmadingen, Germany. The effectiveness of CAE-based crash performance assessments considerably depends on the ability of the numerical model to predict the actual material behavior including fracture. In this paper, the user material model MF GenYld + CrachFEM coupled with LS-Dyna is used to model the fracture behavior of an EN-AW 6082 T6 aluminum extrusion alloy used for aluminum bumper cross-members. The model parameters are identified in a comprehensive testing program. Based on a 3-point bending validation test of a bumper profile, the performance of the material model and the influence of the element formulation are investigated.