Study On Prediction And Control Of Vehicle Interior Noise

Applying FEM, BEM and other modern design and analysis method 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 its influence factor and control measures is attempted in the dissertation, which can provide theoretical support for car interior noise and improve the car interior noise quality on the one hand and try to find out a complete forecast, analysis and control method so as to enrich the research of low car interior noise on the other hand. First, the finite element model of car body, 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 established. Then, a further research on the dynamic characteristics of the car body structure, acoustic characteristics of compartment cavity sound field and the dynamic characteristics of car body structure-compartment cavity sound field structure-acoustic coupling system is carried out by means of dynamic analytical technology for structure and sound field. On this basis, the dissertation analyzes car compartment acoustic response of coupling system by the stimulation of the motor and road surface. The result shows that the sound pressure level increase with the increase of motor speed and no apparent formant appears in the range of the engine operating speed. The result also shows that the sound pressure level of the measuring point in the back seat is higher than that in the front seat and the pressure level of the measuring point in right passenger position is higher than that in the driver position. Further panel acoustic contribution analysis shows that front floorboard, rear floorboard, firewall and roof panel have much correlation with the noise caused by the front and back seats and is mainly contributed to car interior noise. At last, the paper studied the factors, which influence the spread of the noise in the car. On this basis and combining characteristics of the car, corresponding improving and control measures are put forward. The analytical result shows that the sound pressure level decrease 2dbA averagely, thus the quality of car interior noise is improved.