Simulation of rail roughness growth on small radius curves using a non-Hertzian and non-steady wheel-rail contact model

A time-domain model for the prediction of long-term rail roughness growth on small radius curves is presented. Both lowfrequency vehicle dynamics due to curving and high-frequency vehicle-track dynamics excited by short-wavelength rail irregularities are accounted for. The influence of non-Hertzian and non-steady effects in the wheel-rail contact model on rail wear is studied. The model features a refined contact detection algorithm that accounts for wheelset yaw angle as well as surface irregularities and structural flexibilities of wheelset and rail. The development of corrugation on a small radius curve is found to be highly influenced by the wheel-rail friction coefficient. For vehicle speed 25 km/h and friction coefficient 0.3, predictions of long-term roughness growth on the low rail generated by the leading wheelset show decreasing magnitudes in the entire studied wavelength interval. For friction coefficient 0.6, roughness growth is found at several wavelengths. The corresponding calculation for the high rail contact indicates no roughness growth generated by the trailing wheelset independent of friction coefficient. The importance of accounting for the phase between the calculated wear and the present rail irregularity is demonstrated