Abstract: Based on the theory of multi-body system dynamics and the analytical method of finite element and boundary element, the finite element model of vehicle body, the rigid-flexible coupled model of vehicle and the acoustic boundary element model of carriage were established by applying a variety of simulation softwares. Road roughness and engine vibration were simulated and the SPL of field points in carriage under these excitations were computed at the frequency range of 20-150Hz. Considering the size and the positive /negative nature of panels’ acoustic contribution at SPL peak of field points, damping treatments were taken on different combinations of panels to decrease multiple field points’ SPL peak and the optimal treatment was finally confirmed. The results show that the amplitude and frequency distribution of the field point SPL peak are related to the frequency distribution of the exciting force’s energy and structural modal. The frequency distribution of SPL will be changed by adhesiveing damping materials, which can reduce noise at the same time. The noise reduction measures can generally decrease the SPL peak around the Crew.

摘要： 基于多体系统动力学理论、有限元和边界元方法，使用多种仿真软件建立车身结构有限元模型、整车刚柔耦合系统模型和车厢声学边界元模型，对路面不平度和发动机振动两种激励进行模拟，计算了这两种激励条件下20～150 Hz频率范围内车厢内各场点的A计权声压级。以降低多个场点声压级峰值为目标，综合考虑车厢壁板对各场点声压级峰值的声学贡献度大小和正负性质，对不同壁板组合进行阻尼减振降噪处理，最终确定最佳阻尼降噪方案。结果表明：场点声压级峰值的大小和频率分布与激振力能量的频率分布有关，粘贴阻尼材料在降低噪声的同时，也会改变声压级的频率分布。降噪措施能普遍降低车厢内乘员耳旁的声压级。

关键词: 声学, 路面不平度, 发动机激励, 声学贡献分析, 阻尼降噪