Numerical modeling of wheel-rail squeal-exciting contact

Complex frictional rolling contact and high-frequency wheel dynamic behavior make modeling squeal greatly challenging. The falling-friction effect and wheel mode-coupling behavior are believed to be the two main mechanisms that generate unstable wheel vibration and the resulting squeal noise. To rigorously consider both mechanisms in one model, we propose an explicit finite element (FE) model to simulate wheel-rail dynamic frictional rolling. Wheel-rail squeal-exciting contact is investigated with considerations of dynamic effects, unsteady lateral creepage and velocity-dependent friction. With the inclusion of the dynamic effects in the contact solution, large-creepage-induced waves, which share features with Rayleigh waves, are discovered. The solutions of the dynamic contact calculated using the proposed model indicate that the explicit FE method is able to reproduce the falling-friction effect. The transient analyses of wheel-rail frictional rolling with wheel lateral creepage show the coupling of the axial and radial dynamics of the rolling wheel model, suggesting that the explicit FE method can also reproduce the mode-coupling behavior. This study improves the understanding and modeling of squeal-exciting contact from the perspective of wheel-rail dynamic interaction.