A Model for Predicting the Evolution of Vertical Vehicle-Track Interaction

Vertical track stiffness and its variation as well as the variation of vertical track geometry along the track are one of the main sources for dynamic wheel-rail contact forces. These dynamic forces contribute to the track settlement. If these local settlements vary along the track, geometric irregularities develop further amplifying the dynamic loading of the track caused by the interaction between the vehicle and track. Here, a simple and fast, physical-based dynamic vehicle-track interaction (VTI) modeling approach is presented for predicting the evolution of vertical track geometries. The settlement model implemented into the VTI model is calibrated using the evolution of peak-to-peak values (track quality parameter) measured in the field over 350 days for a track where only concrete sleeper was used. Using this calibrated settlement model, the physical-based VTI model can predict the evolution of an another track quality parameter, standard deviation, for this track section. The model could also describe the different evolution of track geometry quality for another track section where concrete sleeper with Under Sleeper Pads (USP) are used. Finally, the calibrated VTI model is used to assess the track geometry deterioration when the vehicle properties are changed. The efficient, physical-based VTI model can assist in designing and optimizing tracks and in supporting of maintenance activities.