Some Aspects Concerning the Wheel Flat/Rail Interaction

The flat is a fault of the rolling surface of the railway wheel, which occurs when the wheel is blocked during braking process. When a wheel having a flat fault is rolling on the rail, a periodic impact force occurs, which is soliciting the rail and generates impact noise. The present work studies the interaction between a wheel having this particular fault and the rail, using a model in which the rail is considered to be a continuous supported beam on two elastic layers. The wheel is taken as a simple mass driven by the stationary load. The Green's functions method is applied in order to solve the equations of motion. The influences of the speed, flat geometry and wheel mass upon the maximal impact force are studied.