Natural Vibration Analysis of A Three-Dimensional Railway Vehicle-Track System

This paper presents natural frequency analysis of the individual components of the railway vehicle and entire track system obtained through eigenvalue analysis. Natural frequencies of the vehicle components have been identified considering rigid body mass. In order to identify the natural frequencies of the track, the three-dimensional railway track model has been simplified to a generalized track element with equivalent stiffness representing the railpad and ballast stiffness and sleeper mass. The nonlinear Hertzian contact stiffness has been converted in linear contact stiffness in order to facilitate the eigenvalue analysis of the vehicle.

Linear parameters of the railpad and ballast stiffness have also been considered for eigenvalue analysis of the track model while damping properties of the railpads and ballasts are ignored. The study shows that natural frequencies of the car body are far less than the natural frequencies of the wheelsets, which in turn shows that the influence of primary suspension is negligible due to relatively large wheelset stiffness. The fundamental natural frequency of the track is found as 161.54 Hz, which is slightly higher than the reported study with different parameters.