Prediction and reduction in vehicle noise by frequency response function–based substructuring

Abstract

The purpose of this study was to use a hybrid frequency response function–based substructuring synthesis method to predict the structure-borne noise of a vehicle frame resulting due to excitation by the engine and to develop a noise reduction method for optimizing the subframe model. The finite element models of the subframe were first verified by comparing their natural frequencies and frequency response functions with those of the real subframe models. Several substructures were then defined and the vehicle interior noises were predicted using the hybrid frequency response function–based substructuring synthesis method. Based on the prediction results, different target frequency ranges were selected, and different methods for optimizing the subframe model to reduce noise were investigated within the selected frequency ranges. Finally, the subframe modes within the selected frequency ranges were analyzed and new noise reduction models were developed by modifying the thickness of parts of the original subframe.