A numerical study on waves induced by wheel-rail contact

Abstract

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.

Wheel-rail dynamic interaction

“…The main difference of the FE and boundary element (obtained with CONTACT) contact solutions is that the waves are observed in the micro-slip distributions calculated with the explicit FEM in Fig. 7.6E and F. The waves have been identified as the Rayleigh wave [42]. This confirms the transient/dynamic effects are included in the explicit FE contact modeling, which is needed for a correct representation of the squeal mechanisms [43].…”

“…According to the generation mechanism, the waves are categorized as the impact-induced wave, largecreepage-induced wave, and perturbation-induced wave. See [42] for the descriptions of the three types of waves. The generation mechanisms of the former two are evident: the significant dynamic effect or kinetic energy [44] induced by the wheel-rail impact or large creepage results in large oscillations of the wheel/rail surface material particles in the vicinity of the contact patch; the large local oscillations then propagate and form regular wave patterns.…”

Shear Wave Splitting and Polarization in Anisotropic Fluid-Infiltrating Porous Media: A Numerical Study

“…With regard to the surface waves, the Rayleigh waves have been properly reproduced: such waves propagate according to cylindrical wavefronts; the resulting motion on the vertical plane is retrograde elliptical (Figures 12d,e and 17c,d) (compare, e.g., with Yang and Li [44]). If considering Love waves (Figure 12f, the generated horizontal vibrations clearly appear polarized along a direction orthogonal to the propagation one (shear deformations).…”

Analysis of Rail Corrugation Characteristics on High-Speed Rail Based on Transient Finite Element Method

“…The transient dynamic analysis methods mainly included both the explicit time integration method and the implicit time integration method. 23 The differences between them lied in the solution procedure of node velocity. The explicit time integration method solved the node velocity directly through the node calculation, while the implicit time integration method used the iterative approach to solve the equilibrium equations of the system.…”