Experimental Procedure and Hardening Model for Simulation Considering Forming and Baking Effects
The automotive body is manufactured by assembling parts made by forming, and then going through a painting process. Sheet metal parts formed by press have the plastic strain, and bake hardening that material strength increases according to the plastic strain during the baking process of painting, occurs. Therefore, the actual assembled automotive parts are stronger than the original materials due to the combined effects of work hardening and bake hardening. Automobile crash analysis generally applies the properties of the original material, but the change of material properties in real parts acts as a factor of error in crash analysis. Especially, these characteristic is more pronounced in giga-steel. Considering the increasing trend of giga-steel for weight reduction, it is necessary to consider the change of material properties due to work hardening and bake hardening in crash analysis.