某车型排气系统振动特性分析及优化设计

Vibration characteristics analysis and optimization design on exhaust system of a vehicle model

某车型在NVH性能测试中的隔振性能较差,经测试分析后确定其原因为排气系统吊钩的传递力过大。为了改善该车型的隔振性能,文章建立了排气系统的有限元模型并分析其振动振动特性。然后,选取5个橡胶吊耳的刚度作为设计优化变量,以5个吊钩的传递力为优化目标,通过ISIGHT平台集成多种有限元软件自动建立了橡胶吊耳Z向刚度与传递力峰值的响应面近似优化模型,采用LSGRG算法求出近似模型的最优解,达到了对吊耳刚度优化的目的。

The vibration isolation performance of a vehicle was poor in the NVH performance test. After test and analysis, it was determined that the reason was that the transmission forces of the exhaust system hook were too large. In order to improve the vibration isolation performance of this model, its finite element model was established, and vibration characteristic was also analyzed in this paper. Then the stiffness of the 5 rubber lifting lugs were selected as the design optimization variable, and the transmission force of 5 lifting lugs was taken as the optimization objective, an approximate optimization model of the response surface of zdirection stiffness of rubber lifting lug and the peak of transmission force was established automatically by integrating various finite element software on the ISIGHT platform. LSGRG algorithm was used to find the optimal solution of the approximate model, which has achieved the goal of optimizing the stiffness of lifting lug.