A Time-Domain Model for the Study of High-Frequency Wheelset–Track Interaction

Abstract

A mathematical model of dynamic wheelset–track interaction is proposed in this paper. The model is defined in the time domain in order to introduce and correctly evaluate nonlinear and time-variant phenomena related to the contact model and boundary conditions which play a very important role in rail surface degradation phenomena. The complete model can be divided into three main components: the model of the wheelset, the model of the track and the model of wheel–rail contact forces. In the paper, the wheelset is described as a rotating flexible body, and the gyroscopic and inertial effects associated with wheelset rotation are introduced to this model using an ‘Eulerian’ finite element approach based on 3D quadratic solid elements. The discrete supported track is modelled using finite Timoshenko beam element, which takes into account both the vertical and the lateral rail vibration valid up to 1500 Hz. The wheelset and the track are coupled by means of a contact model based on the nonlinear Hertz and Kalker theories. The flexible components of the interaction model make it possible to describe the train–track dynamics in a relatively high-frequency range, which allows the investigation of specific aspects such as rail corrugation. Some numerical results are presented in terms of contact forces and rail–wheel vibration speed in the paper. The effect of wheelset and track flexibility in specific frequency range on train–track interaction dynamics is briefly discussed.