Identification of Physical and Excitation Parameters of Under-Chassis Equipment for Railway Vehicles

The accuracy of the physical parameters and excitation parameters of the under-chassis equipment has a significant impact on investigations of the coupled vibration of the vehicle body and the under-chassis equipment. In this study, an equipment vibration isolator test bench is used to develop a physical parameter identification method based on the free vibration acceleration response of the equipment and an excitation parameter identification method based on the forced vibration acceleration response. The equipment mass parameter and the center of the gravity position parameter can be obtained first through a static load test, and then, the inertia parameters can be obtained through a dynamic test. Identification of the excitation parameters of the equipment is based on the physical parameters and the acceleration response. The accuracy of the physical parameters directly affects the excitation parameter identification results. The larger the frequency ratio, the smaller the identification error will be, and the larger the damping ratio, the larger the identification error will be. The identification test results of single-frequency excitation and multifrequency excitation show that the proposed excitation parameter identification method has high accuracy.