In order to improve the performance of vehicle’s passive safety and other performance,engine compartment of a domestic car was optimized.According to the original geometric model,a finite element analysis model was established and the static,modal and 100%RB(rigid barrier) collision analysis were executed.Considering the general arrangement and the joint position of the car,the solid element model was established and the multi-case topology optimization was carried out.Size optimization was implemented for the original design under the integrated case which includes static,modal and equivalent-static 100% RB case.According to the results of topology optimization and size optimization,the FEM was modified and validation was carried out. The results indicate that the performance of 100%RB impact has been improved and the first order bending mode, bending stiffness, torsion stiffness of the front end are increased nearly by 10%, respectively.

crashworthiness, topology, size optimization, equivalent impact force

为了改进汽车碰撞安全等性能,对国内某轿车新产品前舱进行了优化分析。根据原有几何模型，建立了有限元分析模型并进行了静力、模态和100％RB碰撞分析；参考该车总布置和接头位置，建立了前舱结构的局部体单元模型并进行多工况拓扑优化；对原设计进行了静力、模态和等效静态100％RB碰撞综合工况结构尺寸优化；根据优化结果修改模型，并进行了校核计算。结果表明：经过优化，车身100％RB碰撞性能得到改善且前舱一阶弯曲模态、弯曲刚度、扭转刚度均提高近10％。 

碰撞安全性, 拓扑, 尺寸优化, 等效碰撞力