Transfer Path Analysis Of Cab Vibration Based On OPAX Method

In recent years, with the continuous improvement of people’s living standards, moreattention is paid to vehicle ride and comfort. Therefore, how to find out and solve theproblems in short time to effectively improve the NVH performance of the car is one ofthe important issues during current automotive product development process.Transfer path analysis method is one of the most important automotive NVHperformance study method based on testing, which is mainly used to evaluate thesystem noise-vibration transmission path, including the source load identification andcontribution of path. The traditional TPA method and OPA method is sketched in thispaper. The theoretical basis of OPAX method is elaborated, and its data preparation,modeling process, parametric load identification model and scalability are introduced,thus to indicate that the OPAX method makes up the first two deficiencies in accuracyor efficiency. OPAX method proves to be better used in engineering practice.For a domestic medium truck cab whose vibration problem is serious during trialstage, OPAX Method is used in this paper for powertrain-cab and frame-cab vibrationtransfer path analysis. System frequency response function test, operational dataacquisition, parametric load modeling, identification of operational load and pathcontribution analysis are carried out. The transfer path analysis model proves to becorrect while the reason why cab body and steering system’s vibration level is higher isfind out. Finally, feasible improvements are proposed on powertrain mounting, cab bodymounting and steering system structure.