Abstract: In the automotive industry, structural optimization related to crashworthiness and energy absorption capability is of great importance, which involves highly nonlinear computational analysis and design with many material and structural parameters. Unfortunately, conventional design, analysis techniques and the experiments can only improve the structural crashworthiness to a limited extent, and in most engineering design problems there are several conflicting objectives that have to be considered for optimization. In order to improve crashworthiness design, a method using a multi-objective optimization technique based on stepwise regression model is presented through the applications of design of experiments and response surface models and finite element simulation technique. The method is applied for the multi- objective optimization design of the reinforced members of a vehicle, where the mass, toe board intrusion, and the integrated value of collision acceleration are chosen as the objective functions. The results show the new computational design method is a practical tool for the crash safety design of vehicles.

Key words: Crashworthiness, Multi-objective optimization Finite element method, Stepwise regression