Wave Propagation in Railway Tracks at High Frequencies

Abstract

In terms of the long range rail inspection, rail vibration which can propagate over long distances along rails may be a useful tool to detect rail defects. In order to understand long range wave propagation in railway tracks, it is required to identify how far vibration can travel along a rail. To answer this question, the attenuation characteristics of all propagating waves should be determined. In this work decay rates of propagating waves are investigated for frequencies up to 80 kHz. The Wavenumber Finite Element (WFE) method is used to represent a track which has a rail on a continuous foundation. Different damping loss factors are introduced in this model for the damping in the rail and in the foundation. By this simulation, the efficient wave types and their decay rates are predicted. These are presented in terms of what is measurable on various regions of the rail cross-section. In order to validate the simulation results, an experiment was performed on an operational railway track. The measured results are presented for comparison with the simulated ones and good agreement between them is found.