Multi-objective optimization of crashworthiness for mini-bus body structures

In order to improve crash safety, the body structure of a mini-bus is optimized in this study. One type of multi-objective optimization method is proposed in this article. The peak acceleration a(max) at the B pillar lower end and total mass m of the body in white were set as two objective functions. First, the sample points were generated by Latin hypercube sampling design. Second, based on the evaluation index of 40% frontal offset crash, an approximation model was established by the Kriging method. Then, particle swarm optimization was performed on the approximate models. Finally, the simulation calculation by LS-DYNA proved that the peak acceleration a(max) at the B pillar lower end was reduced by 18.6%, and the total mass m of body in white was reduced by 0.87%. Therefore, the crashworthiness of the mini-bus was improved greatly without increasing the total mass of the body in white, which means that the optimization results were meaningful.