The Numerical Simulation Study Of The Vehicle Interior Noise

In this dissertation, a car is taken as the research project. Applying finite element numerical analysis, BEM and acoustic CAE technology, according to domestic and foreign noise rules and regulations and basing on the status of the noise problem, the analysis and forecast of car interior noise and its influence factor and control measures is discussed, which can provide theoretical support for car interior noise and improve the car interior noise quality. On the other hand, this dissertation tries to find out a complete forecast, analysis and control method so as to enrich the research of low car interior noise. The contents of the dissertation include:1. The finite element model of the body-in-white, the finite element model of the car body, the acoustic finite element model of compartment cavity sound field and the structure-acoustic coupling finite element model of car body structure-compartment sound field are built first.2. Applying the structure finite element dynamic analysis technology, the dynamic characteristics analysis is applied on the structural finite element model. In the meanwhile, the modal test of the body-in-white is carried through. Through the comparison between the test results and finite element analysis results, it can be found that the relative error is in the allowable range, and their mode shapes fit quite well. Thus the finite element model can be guaranteed to be right and can reflect the dynamic characteristics of the physical car body.3. Applying the acoustic finite element theory and software, the acoustic characteristics analysis is applied on the acoustic finite element model and the dynamic characteristics analysis is applied on the structure-acoustic coupling system.4. Applying the structure dynamics and acoustic finite element theory and software, frequency response analysis is applied on the car body. The analysis result is imposed on the acoustic finite element modal as the boundary conditions. By calculating, the prediction and simulation of the of the vehicle interior noise are realized successfully.5. Applying BEM theory and software, panel acoustic contribution is analyzed. According to the analysis results, de-noise processing is implemented on the car body structure. 6. By comparing the size of the car interior noise before and after the de-noise processing of the car body structure is implemented, it could be found that the sound pressure level of the typical point decrease 4dbA averagely. The validity of the vehicle interior noise control is verified.