中文摘要：

针对重型车底盘车架的设计问题,提出一种基于多工况和二次局部优化的整体拓扑优化方法.根据商用车底盘实际尺寸,建立其结构拓扑优化模型.基于7种典型行驶工况得到初始拓扑结构,再根据不同工况对其局部二次拓扑优化得到最终车架优化结构,最后对其进行有限元仿真对比分析.结果表明：新车架结构质量减轻约30 kg,其刚度、强度及模态性能与原车架相比均有一定程度的改善,验证了所提出的二次拓扑优化方法的有效性.

英文摘要：

To solve the design problem of heavy commercial vehicle chassis, a global topology optimization method based on multi-load conditions and quatric local-optimization was proposed. A structural topology model was constructed based on the real sizes of commerical vehicle chassis. A preliminary topology structure was obtained based on seven typical loading conditions of the vehicle, and the final chassis optimization structure was obtained with the quatric- topology- optimization method based on different loading conditions. Finally,the finite element validation was given. The results showed that the new chassis mass reduced by nearly 30 k g ,and its stiffness,intensity and modal quality improved to a certain extent compared to the current one, and the effectiveness of the proposed quatric- topology-optimization method was verified.