客车排气系统振动特性优化及试验验证

摘要

为提高某国产轻型客车的乘坐舒适性，解决车内排气系统侧车身地板振动较大的问题，通过与对标车进行道路试验对比分析，发现排气系统吊挂点位置和吊挂悬置刚度的设计并不合理，导致排气系统向车身传递的振动过大。基于平均驱动自由度位移法（ADDOFD）分析计算，得到所有参考点的各阶模态振型加权求和，重新选择平均驱动自由度位移较小的位置作为排气系统吊挂点；综合考虑吊挂悬置隔振效果和耐疲劳性能，对吊挂悬置刚度进行优化设计。最后，对排气系统吊挂位置和吊挂悬置刚度优化设计提出最优改进方案，并进行试验验证分析，试验结果验证了该优化方案的有效性与合理性。%In order to improve the ride comfort of a domestic light bus and reduce the large abnormal vibration of the body floor on the side of exhaust system, the road test of the bus is carried out and the results are compared with those of the competitive bus. It is found that the unreasonable layout and stiffness of the hangers of the exhaust system cause the excessively large vibration of the vehicle’s body. Based on the average driving DOF displacement (ADDOFD) method, the weighted summations of modals at all reference points are calculated. The reference points, where the ADDOFD displacement responses are smaller, are chosen as the locations of the hangers of the exhaust system. The stiffness of the hangers is optimized according to the requirement of the vibration isolation effect and fatigue resistance characteristics. The optimal scheme for design is proposed and the test analysis is performed based on the optimization of the hanger’s layout and stiffness. The effectiveness and rationality of the optimization method are verified by the test results.