Research On Side Wall Cavity Barrier Structure Based On Acoustic Energy Transfer Path Analysis

The interior noise level is one of the most important indexes to evaluate the vehicle NVH performance.The side wall cavity barrier structure has a significant suppression effect on the high and medium frequency noise in the vehicle.The installation position of the side wall cavity barrier structure in the side wall cavity has a great impact on the suppression effect.At present,there is a lack of research on the specific application of side wall cavity barrier structure in vehicle body in China,so it is very important to propose a method to analyze the correlation between side wall cavity barrier structure and vehicle interior noise based on the existing theories such as statistical energy method.Based on the transmission loss test theory,a side wall cavity barrier structure is selected,and the transmission loss of the barrier structure is simulated by transmission loss simulation analysis,and the transmission loss of the barrier structure in different frequency bands is obtained.By analyzing and comparing the existing modeling methods and specifications,the specific application of cavity barrier structure model in different vehicle acoustic models is studied.Based on the finite element method,statistical energy method and FE-SEA method,the FE model,sea model and FE-SEA hybrid model of a certain vehicle are established.The acoustic energy transfer path of the excitation source response cavity is analyzed,and six kinds of acoustic energy transfer paths in the side wall cavity are summarized.On the basis of the analysis results,the pre installation scheme of the side wall cavity barrier structure is proposed,and the path sound insulation analysis is used to optimize the pre installation scheme,and the optimal installation position of the barrier structure in the side wall cavity is obtained.Based on the optimization results,the side wall cavity barrier structure is installed in the Fe vehicle model.The influence of the installation of the side wall cavity barrier structure on the modal distribution and vibration transfer function of the vehicle is compared.It is concluded that the barrier structure will not affect the modal distribution of the vehicle too much.The results show that the sound energy transfer path analysis and path sound insulation analysis can quickly and effectively establish the installation scheme of the side wall cavity barrier structure for a certain vehicle,which can significantly reduce the overall noise level of the passenger compartment and the noise near the driver’s ear.