Hunting stability analysis of high-speed railway vehicle trucks on tangent tracks

Using the linear creep model, this paper derives the governing differential equations of motion for a truck moving on tangent tracks. The truck is modeled by a 10 degree-of-freedom (DOF) system which considers the lateral displacement, vertical displacement, roll angle and yaw angle of each wheelset and the lateral displacement and yaw angle of the truck frame. It is shown that the critical hunting speeds evaluated using the 10-DOF system differ significantly from those calculated using a system with six-DOF. The influences on the critical hunting speeds of certain physical parameters not considered in the six-DOF system are evaluated for wheels of different conicities. The accuracy of the present analysis is verified by comparing the limiting case and the current numerical results with the findings available in published literature.