Numerical study of wheel/rail dynamic interactions for high-speed rail vehicles under low adhesion conditions during traction

The evolution of wheel-rail dynamic interaction of a high-speed railway vehicle is essential for the simulation of wheel-rail rolling contact damage under low adhesion conditions. The main objective of this study is to reproduce the dynamic wheel-rail interaction behaviour under various interfacial contaminations by experimental and numerical modelling methodology. Firstly, the wheel-rail adhesion characteristics under different interfacial contaminations were obtained. Subsequently, a simplified numerical methodology was proposed to extract the parameters from the high-speed adhesion tests to modify the simplified theory of Kalker (FASTSIM). The initial slop reduction factor and the slip-velocity-dependent coefficient of friction (COF) were introduced based on the high-speed experimental curves. Furthermore, the modified wheel-rail rolling contact model was incorporated into a longitudinal vehicle-track coupled dynamic model. The wheel-rail dynamic interaction behaviours under different operational conditions were attained. Finally, the wheel-rail wear performances were primarily investigated for typical traction coefficients under wet conditions. Results show that the wheel-rail creep force drops dramatically when the wheel enters the low adhesion zone (LAZ). There is a sudden increase in the creep force when the adhesion recovers. In addition, the wheelsets begin to slide and have severe wear at LAZ when the traction coefficient is larger than 0.1 at high speed.