Transfer path analysis and its application to diagnosis for low-frequency transient vibration in the automotive door slamming event

Transfer path analysis (TPA) method has been widely used in the frequency-domain applications. However, it is not suitable for transient vibration problems such as the abnormal vibration in the automotive door slamming event. In this paper, two time-domain TPA models are used for the abnormal transient vibration diagnosis in the automotive door slamming event whenever the door glass is located at its lowest location. To obtain the excitation forces, lab experiments have been carried out for the whole vehicle and door system. In the experiment, a door closing velocity device is built to maintain the closing speed (1.5 m/s) to obtain the operational responses of the indicator points on the 1st and 2nd transfer paths, as well as the target points. The frequency response functions (FRFs) for the 1st transfer path are then recorded using the experiment, including the excitation points to its indicator points and the excitation points to the target points. The FRFs for the 2nd transfer path are obtained using the finite element analysis (FEA), including the excitation points to its indicator points and the excitation points to the target points. With the two time-domain TPA models, the contribution of each transfer path can be obtained. The results show that the two time-domain TPA models can predict the transient vibration in the door slamming event. They also show that the main transfer paths of the abnormal vibration are from the upper door frame on the 1st transfer path and the regulator channel on the 2nd transfer path. These results provide insights for the improvement of the regulator channel and glass run channel designs in order to mitigate the abnormal transient vibration in the door slamming event.