Wave Propagation and Vibration Behaviour of a Railway Track

A wave approach based on the wave propagation in an infinite beam resting on Winkler’s foundation is used to investigate the vibration behaviour of railway track from the viewpoint of wave motion. The rail is considered as an infinite Timoshenko beam, in which the effects of shear deformation and rotatory inertia are taken into account to reflect its dynamic behaviour at high frequencies. The track support, which is modelled as a continuous elastic foundation with an equivalent stiffness, consists of the fastening system, the sleeper inertia and the track subgrade. The properties of waves in the track corresponding to various frequencies are illustrated by the dispersion curves, through which the passing bands and stop bands of the track system are identified. The vibration behaviour of railway track with and without unsprung masses is investigated using the wave propagation method in an exact and efficient way, which reflects the intrinsic physics between the wave motion and the resonances of the system. The results obtained help to gain insight into the interaction of the high-speed train and the track, especially for the research on the high-speed rail corrugation, wheel polygonisation and the ground vibrations generated by the high-speed train. Both the model and the method provide useful tools for the optimised design of the higher-speed railway system.