The Simulation And Optimization Of The Vehicle Interior Noise

Applying acoustic FEM to analyze, forecast and control car interior noise is a research hot point. Domestic research in this field is immature and there are few successful instances. Combining the development of a new car, the analysis and forecast of car interior noise and control measures is attempted in the dissertation, which can provide theoretical support for car interior noise and improve the car interior noise quality and try to find out a complete forecast, analysis and control method so as to provide a systematic for low car interior noise.First, the finite element model of the body-in-white, the finite element model of 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 are built, applying the structure finite element dynamic analysis technology, the dynamic characteristics analysis is applied on the structure finite element model. In the meanwhile, the modal test of the body-in-while 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 modal can be guaranteed to be right and can reflect the dynamic characteristics of the physical car body. Then, applying the acoustic finite element theory and software, the acoustic characteristics analysis is applied on the acoustic finite element modal and the dynamic characteristics analysis is applied on the structure-acoustic coupling system. On this basis, the dissertation analyzes car compartment acoustic response of coupling system by the stimulation of the motor, and analyzes the panel acoustic contribution of the car; the prediction and simulation of the vehicle interior noise are realized successfully. At last, according to the analysis results of the panel acoustic contribution, the structure of the car body is optimized. By comparing the results of before and after optimization, it could be found that the sound pressure level of the point is decreased averagely. The quality of car interior noise is improved. The validity of the vehicle interior noise control is verified.