Abstract
This paper investigates the influence of mechanical nonlinearity at the interface between the sleeper and ballast on the critical velocity of moving lateral load acting on an axially stressed rail. To this end, a mathematical model consisting of an elastic half-space and an infinite beam is considered. Taking into account the nonlinear stiffness in the interaction system, the critical velocity is derived via dispersion corves drown in the wavenumber-frequency space. The sensitivity of the critical velocity to the disturbance represented by a lateral moving load is revealed through theoretical discussion. Furthermore, in order to verify this phenomenon, steady-state solutions governed by the hysteresis property of the ballast material are obtained numerically for a compressed beam subjected to a moving load.
