A finite element study on rail corrugation based on saturated creep force-induced self-excited vibration of a wheelset–track system

The present work proposes friction coupling at the wheel–rail interface as the mechanism for formation of rail corrugation. Stability of a wheelset–track system is studied using the finite element complex eigenvalue method. Two models for a wheelset–track system on a tight curved track and on a straight track are established. In these two models, motion of the wheelset is coupled with that of the rail by friction. Creep force at the interface is assumed to become saturated and approximately equal to friction force, which is equal to the normal contact force multiplied by dynamic coefficient of friction. The rail is supported by vertical and lateral springs and dampers at the positions of sleepers. Numerical results show that there is a strong propensity of self-excited vibration of the wheelset–track system when the friction coefficient is larger than 0.21. Some unstable frequencies fall in the range 60–1200 Hz, which correspond to frequencies of rail corrugation. Parameter sensitivity analysis shows that the dynamic coefficient of friction, spring stiffness and damping of the sleeper supports all have important influences on the rail corrugation formation. Bringing the friction coefficient below a certain level can suppress or eliminate rail corrugation.