Dynamic response of high-speed rails due to heavy braking

The dynamic response of a high-speed rail experiencing heavy braking is investigated using the moving element method. Possible sliding of train wheels over the rails as the train decelerates is accounted for. The train is modelled as a 14-DOF system comprising a car body, bogies and wheel sets interconnected by spring-damping units. The railway track is modelled as an infinite Euler–Bernoulli beam resting on a two-parameter elastic-damped foundation. A convected coordinate system attached to the moving train is employed in the formulation of the governing equations. The effects of braking torque, coefficient of static friction between wheels and rail, initial train speed and the severity of railhead roughness (track irregularity) on the dynamic response of the high-speed rail, including the occurrence of the ‘jumping wheel’ phenomenon, are examined. The phenomenon describes the momentary loss of contact between the wheel and track. A combination of high braking torque, large static friction coefficient, high initial train speed and severe track condition promotes larger dynamic effects.