基于改善整车加速噪声的试验及仿真方法

Simulation and Experiment Method Based on Trouble Shooting for Reducing the Automotive Acceleration Noise

为了解决车辆在加速时发动机激励引起的车内噪声问题,进行了整车试验,得到噪声问题的主要频率特征。通过车辆加速时悬置被动侧振动加速度以及整车各个部件模态、振动灵敏度等数据确认了引起车内噪声的关键部件。首先,建立了整车有限元模型,仿真得到了关键部件模态;其次,通过试验验证了模型的有效性;然后,利用所建的整车模型对各部件进行改进,有效降低了各传递路径对车内噪声的灵敏度;最后,根据仿真结果提出了改进方案并进行装车验证。结果表明:车内的加速噪声主要由下拉杆悬置、副车架及前围板等部件与整车声腔模态耦合引起;改进后车内噪声明显改善,声压降低了8~9 dB。

Vehicle accelerating noise is a troublesome issue commonly existing in automobiles.To improve this issue,the characteristics of frequency of accelerating noise are confirmed by real experimental results.The important components which cause the interior noise are identified by the passive side acceleration of the engine mount and the modal of each component on the vehicle.The finite element model of vehicle is established and the model is validated by experimental results.The improvement program is proposed in finite element model and implemented in the vehicle.The results show that the accelerating noise in the vehicle is mainly caused by the modal of lower tie bar,sub-frame and cowl panel.The accelerating noise is reduced by 8~9 dB after imple-ment the improvement program.