Non-smooth dynamics of a magnetic track brake

During the first stages of braking with a magnetic track brake in low suspension impacts occur between the force transmitting components, giving rise to a non-smooth system behaviour. Initially, when the electric current is switched on, the magnet moves down until it impinges on the rail. Thereafter, it is decelerated by the friction force, and subsequently there occurs a first impact of the transmission link of the magnet on the transmission link of the bogie frame. Due to the elasticity of the components there follows a high-frequency series of impacts with decreasing intensity until the velocity of the magnet relative to the bogie frame vanishes. Of course, the occurring forces are multiples of the steady-state ones, and this must be taken into account at the design of the force transmitting components.