Diagnosis of Road-Induced Drumming Noise of Passenger Car Based on Multiple Coherence Method

Due to the fact that the vehicle suspension system is complicated, how to identify the structure-borne path of road noise efficiently and accurately is the key point of road noise diagnosis. In this research, a transfer path diagnosis approach for road noise diagnosis is proposed. In terms of methodology, the proposed method is based on the multiple coherence method, and it also needs to take into account the mechanical transfer paths of road noise. Therefore, the numerical implementation of multiple coherence method is presented first and then the classification of mechanical transfer paths of road noise. As for the practical application, first of all, the presented approach is used to investigate the transfer paths of a 79 Hz road-induced drumming problem of a vehicle. And then the mechanism for above-mentioned problem is predicted combining the modal results of relevant components. Furthermore, the predicted result is validated by adding a tuned 78 Hz damper to the lower control arm on both sides of the rear suspension. The experimental result indicates that the peak value at 79 Hz corresponding to road-induced drumming noise reduces by 10 dB(A), which proves the correctness of the inference for drumming noise and further demonstrates the validity of the proposed diagnosis approach.