Abstract: Multidisciplinary and multi-objective optimization design method is applied in the researches of vehicle side impact crashworthiness and NVH performances. Design of experiment(DOE) is explored to obtain the experimental scheme and perform data sampling, the response surface model (RSM) taking into account the vehicle side-impact safety, body-in-white modal frequency, static bending stiffness, torsional stiffness and lightweight is built. Determined optimization, Reliabilityoptimization and lightweight design are operated independently on the basis of genetic algorithm. Finally, collaborative optimization which is one of the best feasible multidisciplinary design optimization approaches is combined with multi-objective genetic algorithm to carry out the optimization of vehicle body structure. Then the Pareto optimal set is obtained. The results show that the reliability optimization which considers the uncertainties of product design and production process can ensure product stability, and is more accurate than deterministic optimization. The coupling and interdisciplinary relationships of lightweight, NVH and crash safety performancesare comprehensively considered during the multi-objective optimization of vehicle body structure. Thus the Pareto set is obtained and designers can choose the satisfactory optimization results according to their demands, so as to significantly reduce product development cycle and costs.

Key words: Collaborative optimization, Lightweight, Multidisciplinary design optimization, Multi-objective genetic algorithm, Reliability-based design optimization