Thermo-mechanical coupling analysis of wheel/rail contact in case of train hunting motion

Abstract A slight slip on the wheel/rail contact surface during the hunting motion will cause the temperature on the interface to increase, which will influence the contact characteristics and lifespan of the wheel/rail materials. For the purpose of investigating the thermo-mechanical coupling effect of wheel/rail contact during the hunting motion and its influence on the wheel/rail contact characteristics, a three-dimensional (3D) full-size finite element model for the thermo-mechanical coupling of wheel and rail is constructed using Ansys software according to the actual size. The model includes the wheel, rail, pad, sleeper, and foundation system. The wheel/rail contact characteristics, temperature, stress and strain distribution under different creep states of train (lateral creep, longitudinal creep, and spin creep) are researched for freight train travelling at a speed of 40 km/h. The study indicates that the initial contact patch shape of wheel/rail is similar to an ellipse, with an area of 164.3 mm 2 . The lateral creep and longitudinal creep have a significant effect on the temperature. The temperature distribution is sinusoidal waveform, and the longitudinal creep can lead to a temperature rise of up to 58.6 ℃. The spin creep has a little effect on the temperature, stress and strain. During lateral slipping, the contact patch transitions from an elliptical shape to a circular one, and then back to an ellipse. This transformation has a considerable impact on the contact area, maximum contact stress, and its location.