A three-dimensional model for the lateral and vertical dynamics of wagon-track systems

Lateral and vertical dynamics of the wagon and track affects the maintenance and safety of the heavy haul railway operation. With a view to understanding this aspect comprehensively, a three-dimensional wagon-track system dynamics (WTSD) model is developed and presented. The model consists of a full wagon with 37 degrees of freedom (DOF), a four-layer track with discretely supported rails and a wheel-rail interface representing Kalker's creep and Hertzian contact parameters. The model has been validated using two sets of field data: one dealing with vertical impact due to the flat wheel and the other dealing with lateral hunting. The effect of detailed track modelling on lateral hunting is discussed, and the capability of the three-dimensional WTSD model in predicting lateral impact is demonstrated.