Coupled Acoustic-structural Finite Element Analysis of Vehicle Interior Noise Based on Acoustic Sensitivity

It is very important to predict the acoustic radiation of vehicle body for the control of interior noise. Firstly, the control equation of acoustic-structural coupled finite element method (FEM) is derived. The computational methods of modal participation factors and panel acoustic contributions are obtained. Then the acoustic-structural coupled finite element model of a commercial vehicle, including body and interior cavity, is created on the basis of virtual proving ground technique which is employed for the prediction of vehicle interior noise. The connection points between the body and the chassis are chosen as the excitation points of acoustic sensitivity analysis. The acoustic sensitivity from each suspension point to the ears of driver is obtained by using the acoustic-structural coupled FEM. The result of acoustic sensitivity analysis shows that there exist biggish peaks of body modal at its formants which are 70 Hz, 138 Hz and 200 Hz. The frequency points of the three peaks and their structures are studied. The structural and acoustic modal participation factors and panel acoustic contributions are computed. Finally, those panels and structural modals that have most influence on the acoustic response of vehicle are obtained.