Investigation of rolling wheel-rail contact using an elaborate numerical simulation

In this paper, a non-linear model is developed for analyzing rolling wheel-rail contact in a wheel-track-infrastructure system. Because of the random irregularity across the surface of the rail, the process of the wheel accelerating from rest and rolling forward at its expected speed can be simulated and verified. The dynamic characteristics of the rolling wheel-rail contact at the expected speed are also carefully investigated. The results showed that the top of the rail consists of spatially curved planes due to the deformation induced by the rolling wheel. In addition to the adhesion and slipping zones, there was also a disengaging zone existing within the contact area. The random irregularity throughout the top of the rail significantly reduced the area of contact between the wheel and the rail. By comparing the Hertz contact theory with a smooth rail top, significant differences were observed in the vertical contact stress distribution mode throughout the contact area for the real wheel-rail rolling contact, with a sharp increase in the absolute values of contact pressure. The stress distribution in the contact area was highly non-uniform, and a severe local concentration of dynamic stress was observed.