Wheelset skid in railway bogies

Skid of wheelsets leads to uncontrolled severe dynamics of bogies including derailment potential and damage to the running surfaces of the wheel and railhead. Simulation of wheelset skid would enhance the understanding of the skid mechanism and improve the level of safety. To effectively simulate bogie skid, the wheelsets should be modelled incorporating pitch degree of freedom. Such a model, based on a fixed inertial frame reference system, has been recently developed by the first author and is used in this paper to examine the skid of a simplified bogie containing two wheelsets and a bogie frame connected through spring-damper system. The current model accepts braking/ traction torque as a primary input and calculates the longitudinal speed profile, acceleration and distance travelled as a natural process. The calculated results have been validated using VAMPIRE where possible. The ability of the current model in predicting lateral dynamics whilst subjected to longitudinal skid is demonstrated through numerical examples – a feature that could not readily be predicted by most commercial wagon dynamics packages.