The effects on railway rolling noise of wave reflections in the rail and support stiffening due to the presence of multiple wheels

Theoretical models that describe the high frequency dynamic behaviour of railway track, are applied to study two effects of the presence of multiple wheels on the rail. These are the influence of wave reflections in the rail induced by the multiple wheel/rail interactions and the local stiffening of the support due to the preload induced by the vehicle weight. Results are given in terms of overall track vibration, sound power spectra and A-weighted levels, and a comparison is made between tracks with three different types of rail pad. The results show that the preloading and wave reflections have significant effects on the rail receptance and the wheel/rail interaction force, but that their influence on the overall track vibration and noise radiation are limited to about I dB(A) for two of the three pads considered. For the track with soft pads that is considered, the track noise would be over-predicted by about 3 dB(A) if these effects were not included. (C) 2001 Elsevier Science Ltd. All rights reserved.