Analysis And Control Of Bus Body Vibration And Interior Noise

With the development of the automobile market and the improvement of people’s living standard, customers pay more and more attention to the quality of vehicle. In a number of indicators for measuring vehicle quality, NVH performance of the vehicle has become the most important indicator of vehicle quality. Bus is usually used for long-distance passenger carrying; the strong vibration and excessive noise will seriously affect the ride comfort of the drive and passengers in the long running process, and also cause drivers to enter fatigue, then leading to traffic accident. So carrying out research on body vibration and vehicle interior noise and improving the acoustic environment in the bus have great significance for enhancing market competitiveness.Based on some type of bus for the study in the paper, CAE technology is used in the simulation analysis about body vibration and interior noise of the bus. Then developing control measure on the basis of the analysis result to reduce the vibration and noise of the bus in order to improve the ride comfort. The main contents of this article are as follows:Firstly, the bus frame finite element model, the whole bus finite element model and the acoustic cavity finite element model are built with Hypermesh software, and the modal analysis of the three finite element models has been carried out. Then structural finite element model and acoustic finite element model are put into Virtual.Lab acoustic software to link up, namely the acoustic-structure coupling mode is built. The coupling model is analyzed by modal superposition method to get modal parameters. Comparing the modal parameters with structural modal parameters and acoustic modal parameters can find that the coupling effect is remarkable. Then the acoustic sensitivity analysis is carried out in the coupling system to find the peak sound pressure; panel contribution analysis is carried out using ATV method to find the panels which make a greater contribution to the peak sound pressure; besides, frequency response analysis of the bus body is calculated to get the vibration velocity images which can provide reference for the control of vibration and noise. Finally, aiming at reducing the drive’s ear sound pressure, the control measure of vibration and noise is developed. Reinforcement or damping treatment is put on the panels which have great acoustic contribution. By conducting the acoustic response analysis again, the effectiveness of the control measure can be verified by find that the sound pressure of the drive lowers 5.3dB.