An Evaluation of the Dynamic Dent Resistance of Automotive Steels 910287

The effects of sheet thickness, yield strength, strain aging and prestrain on the dynamic dent resistance of sheet steel are investigated using an instrumented drop-weight test. It is found that the dynamic dent resistance is less dependent on the sheet thickness and the yield strength of the material than the static dent resistance. The dent resistance of automotive steels under dynamic loading conditions increases with prestrain in a manner similar to static denting. The relative ranking of different strength steels in the performance of dynamic denting is provided at various strain levels. An empirical relation of dynamic denting force and energy with the sheet thickness and the yield strength of the material is derived for a flat panel. Data confirm that dynamic dent resistance is improved using high strength steels including bake hardenable steels and rephosphorized steels.