为提高某车型排气系统隔振性能,用HyperMesh软件构建排气系统有限元模型并对其进行隔振性能分析,经测试分析发现其传递力过大,通过重新设定将各个吊耳传递力之和及其标准差作为优化目标一;将各个吊耳静态位移之和与预载力标准差作为优化目标二。在HyperStudy软件中通过拉丁超立方采样并进行试验设计(Design of Experiments,DOE),以进行变量筛选,最终确定以6个吊耳的Z向动刚度作为设计变量,并构建响应面模型,用多目标遗传算法(Multi-Objective Genetic Algorithm,MOGA)得出最优的吊耳动刚度值。将最优的吊耳动刚度值代入排气系统有限元模型进行分析,结果表明优化目标均有所提升。最后,将实际生产的吊耳装载后在实际道路上进行测试,试验结果表明,隔振率均大于20 dB,与有限元结果相同,符合生产设计要求。
Research on vibration isolation performance and optimization of exhaust system of a certain model
In order to improve the vibration isolation performance of exhaust system of a certain model,the finite element model of exhaust system was constructed with HyperMesh softwore and analyzed for vibration isolation performance.After testing and analy-sis,the transfer force is too large,the sum of the transfer force and the standard deviation of each ear were reset as the optimiza-tion target 1;and the sum of static displacement of each ear and the standard deviation of preload force were taken as the optimi-zation objective 2.In HyperStudy softwore,the Z-direction stiffness of the six lifting lugs was finally determined by Latin hyper-cube sampling and DOE variable screening,and the response surface model was constructed,and the optimal lifting lug stiffness value was obtained by Multi-Objective Genetic Algorithm(MOGA).The best lifting lug stiffness value was brought into the finite element model of the exhaust system for further analysis,and the results show that the optimization target was improved.Finally,the actual production of lifting lugs was tested on the actual road after loading,and the test results show that the vibration isolation rate is greater than 20 dB,which is the same as the finite element result,which meets the production design requirements.