Study On Control Of A Passenger Car's High Frequency Interior Noise Based On Statistical Energy Analysis

With the improvement of the customer's living quality,their requirements for all aspects of the vehicle are becoming strict.Good control of interior noise is very important for the the driving quality of the vehicle,so domestic and foreign manufacturers have put large amounts of effort on the study of this aspect.In this thesis,the vehicle's high-frequency interoer noise is taken as the object of study,and the statistical energy analysis method is taken as the main method to predict and control a vehicle's high frequency interior noise.This study is of great theoretical and practical value,which can provide reference for the prediction and control of the vehicle's high frequency interior noise.Based on the transmission characteristics of high frequency noise,the superiority of the statistical energy analysis method and its basic theory were introduced.Combined with the current status of statistical energy analysis and current analytical tools,the basic workflow of high frequency noise simulation in this thesis was established,which provides guidance for the whole study.According to the actual situation of the whole vehicle and the needs of analysis,the construction of each subsystem of the whole model was carried out,and then the connection work of each subsystem was completed.Combined with test data and theoretical calculation,the three key analytical parameters of modal density,damping loss factor and coupling loss factor were obtained.Then the parameters of various materials were also obtained by tests and theoritical calculations,and the model of sound package was established based on the test data of the materials.With the aim of benchmarking the model,the PBNR tests under the excitation of the engine and tire point source were carried out.The sound pressure levels predicted by the model agreed well with the measured values.After the benchmarking work was completed,the analysis of the actual acoustic load conditions under the excitation of engine and the tire were carried out,then the transmission characteristics of the vehicle's high frequency interior noise under different excitations can be obtained.At the same time,through the analysis of the power's transmission path,the main object of sound package optimization can also be determined.Through combining the simulation of the flat specimen structure with the overall response of the acoustic package components,the sealing,sound insulation and sound absorption performance of the sound package components were studied.Then the corresponding optimization scheme was proposed,the predicted results shows that the sound pressure level of high frequency interior noise got reduced.In this thesis,the prediction and control method of the vehicle's high frequency interior noise are of some theoretical and practical value,which can gives some guidance for the study on control of vehicle's high frequency interior noise and the development of sound package.