A wheel set/crossing model regarding impact, sliding and deformation—Explicit finite element approach

A dynamic finite element model for the process of a wheel passing the crossing panel of a turnout is presented. This model accounts for the dynamic process, the elastic deformations of the wheel and the elastic–plastic deformations of the crossing. The axle and the second wheel are accounted for in terms of their influence on the angular velocity of the wheel. The model provides the dynamical contact forces between the wheel and the crossing parts, the vertical wheel displacement, the development of the angular velocity of the wheel as well as the stress fields and the plastic deformations in the crossing. Results that indicate the loading of the surface, such as the contact pressure and the microslip, are also provided by the model. From them, the specific frictional work and the maximum of the specific frictional power are derived. Those values are associated with surface damage such as wear and Rolling Contact Fatigue (RCF). An empirical relationship between the frictional work and wear is widely used and called Archardʹs wear law. For the formation and propagation of surface cracks there is no simple relationship. Results for the wheel initially running on the wing rail and then impacting onto the crossing nose (facing move) and the other direction (trailing move) are presented for three velocities. The presented model can help in the optimization of crossings in terms of geometry, bedding and material, depending on the loading conditions such as train velocity, axle load and wheel profile for both the facing and trailing move.