Dynamics analysis of high speed railway vehicles excited by earthquake forces

Based on Kalker´s linear theory and the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of twenty degrees of freedom car system, considering the lateral displacement and the yaw angle of each wheelset, the lateral displacement, vertical displacement, roll angle and yaw angle of the truck frames and the car body moving on curved tracks, are derived completely. The dynamic responses of railway vehicle with the earthquake forces acting on the wheelset in the lateral direction are investigated. From the numerical results, when the earthquake forces are applied, the amplitude of oscillation of a wheelset becomes to be violent as the velocity increases. It can be obtained that the influence of the external forces on the dynamic stability of the vehicle can´t be neglected.