Vehicle Interior Low Frequency Noise Optimum Using Substructure Modal Synthesis Method

Abstract

Combined with the structural dynamic model of a car set up with the substructure modal synthesis method, body panels acoustic contribution was analyzed to reduce the in-car structural noise in low frequency range. The driver-right-ear position was selected as acoustic response point, with the operational vibration response of the dynamic model as boundary condition for acoustic BEM (boundary element model), the panels that attribute most to the in-car noise were located according to ATV (acoustic transfer vector) results. After the vibrational restraint of the crucial panels by corresponding experimental measurement, in idling, the most decrease of main peaks is 5.7dB; the overall level of in-car noise is reduced by 3.89dB. It indicates that the substructure mode synthesis method can provide proper suggestion for optimizing in-car structural noise.