Research on simulated operational path analysis applied to structure-borne road noise

Abstract

The accurate identification of noise sources inside vehicles is the basis of optimizing structure-borne noise problems, and transfer path analysis (TPA) is one of the most commonly used methods. The load-response type TPA represented by the classical TPA has high accuracy but low experimental efficiency. The response-response type TPA represented by the Operational TPA (OTPA) has high efficiency but cannot guarantee its accuracy when the relevant excitation sources act on the system simultaneously or there is a strong coupling between the transfer paths. In this paper, a novel response-response type TPA, simulated operational path analysis (SOPA), balancing efficiency and accuracy is proposed and tested. Without severing the connection between the source and receiver, the system is decoupled by running the simulated loads separately, and the proposed inverse transmissibility matrix method is used to cancel the crosstalk between reference signals, thus solving the problems of path cross-coupling and path neglection of OTPA in multi-input systems. For validation purpose, a four-shaker bench test is analysed, it is found that SOPA is more accurate than OTPA in path contributions analysis. Finally, SOPA is applied to the transfer path analysis of structure-borne road noise inside the vehicle, and it is also shown that the noise can be well predicted. Therefore, the proposed method may be an alternative method in addition to the traditional source-path-contribution analysis.