A numerical study on waves induced by wheel-rail contact

Recent finite element (FE) simulations have revealed the generation and propagation of waves in rail surfaces induced by wheel-rail frictional rolling. These waves have rarely been addressed in the literature. This paper presents an in-depth analysis of these waves, aiming to give new insights into the contact mechanics, a research area in which waves have generally been ignored. The study first categorises the simulated contact-induced waves according to their generation mechanisms as impact-induced, creepage-induced and perturbation-induced waves. The link between the generation of perturbation-induced waves and the stick-slip contact mechanism is then explored. Next, by examining the rail surface nodal motion that forms the wave, the creepage-induced wave is demonstrated to be a Rayleigh wave; this result also shows that the explicit FE method can effectively simulate physical contact-induced waves and provide reliable dynamic contact solutions. Finally, FE modelling is presented to investigate the effects of surface cracks on the waves, which may contribute to wave-based crack detection.