Research on multi-objective optimization of BIW modal

BIW modal optimization with traditional FEM method was inefficiency and usually with much mass increase. FEM analysis combined with Multi-objective Optimization method was used to improve the first order frequency of BIW. Mathematic model was built by response surface method to replace FEM model and NSGA-II was used to get non-dominated solutions. During the optimization plates with high relative sensitivity was used as design variables. The first natural frequency was optimized with the mass of BIW was under control. The method in this paper is useful in big complex structures when do some optimization.