On-resonance transmissibility methodology for quantifying the structure-borne road noise of an automotive suspension assembly

In this paper, a methodology is presented for the analysis of the structure-borne noise transmission paths for an automotive suspension assembly. First, a fully-instrumented test bench consisting of a wheel/suspension/lower suspension A-arm assembly was designed in order to identify the vibro-acoustic transmission paths (up to 250 Hz) for white noise excitation of the wheel. Second, frequency response function measurements between the excitation signal and each suspension/chassis linkages are used to characterize the different transmission paths that transmit energy through the chassis of the car. Finally, a synthesis of the major resonances of the suspension is drawn, with the objective of indicating which suspension transfer paths contribute the most to the structural forces transmitted to the chassis. On-resonance force transmissibility factors (ORTF) were calculated to provide an overall classification of the system resonances to the vibration transmission through the individual suspension linkages and in all axes.