A hybrid model for noise generation from a railway wheel due to wheel/ rail impact

Abstract

A hybrid model is developed for noise generation from a railway wheel due to wheel/rail impact at a rail joint. It consists of a coupled vehicle/track dynamic interaction model working in the time domain and a FE-BE vibro-acoustic model for the wheel working in the frequency domain. In the coupled vehicle/track interaction model, the vehicle is described as a multi-body system, the rail is idealised as a Timoshenko beam resting on discrete sleepers, and the sleepers are treated as Euler beams. The lateral, vertical, and torsional vibrations of the rail are all taken into account. Sleepers are assumed to move backward at the train speed to simulate the travelling of the vehicle along the track. Wheel/rail normal forces are calculated using the Hertzian contact theory and creep forces are determined using Shen's nonlinear creep theory. The differential equations of motion of the vehicle/track system are solved by means of an explicit integration method, giving wheel/rail force time-histories. The wheel/rail force between a wheel and the rail is then transformed into the frequency domain and input to a FE model of the wheel to calculate its dynamic response. Sound radiated from the wheel is then calculated from the surface response of the wheel using the acoustic boundary element method. Results produced from this hybrid model demonstrate its suitability for predicting noise radiation from a railway wheel due to wheel/rail impact. © 2008 Springer-Verlag Berlin Heidelberg.