Relative Movement of Switch/Stock Rails and the Wheel/Rail Interaction Interface

Developing resilient and reliable switches and crossings is one of the key challenges of the railways for the future. Understanding the detailed interaction between the railway vehicle and the track is paramount in order to develop sustainable railway track components. In this paper, an investigation is carried out on the relative movement between the switch and stock rails under dynamics loading and the effect of their relative connection on the wheel/rail interface and the vehicle-track response. To do this, a multibody dynamics software track model is modified and compared to the default approach of using one solid rail profile throughout the switch-stock rail assembly. The results show that significant differences are present when the relative motion between switch and stock rail is accounted for. A sensitivity analysis on the modelling approach and rail-pad stiffness properties is also considered, showing that in comparison there is relatively much less variation based on track support properties. It is concluded that to accurately predict the dynamic behaviour of vehicle and track in switches it is crucial to account for the relative connection between the switch and stock rail and model them as two independent rail bodies.