The influences on railway rolling noise of a rail vibration absorber and wave reflections due to multiple wheels

Abstract

A compound track-absorber model is employed to study the effect of multiple wheels and rail vibration absorbers on a rail, one of the main parts that generate rolling noise. Effects are wave reflections induced by multiple wheel—rail interactions and the increase in the decay rate of vibration along the rail by using a rail absorber. The rail vibration and noise radiation owing to a roughness excitation are studied by comparing the results of calculations with and without rail absorbers and multiple wheels in turn (i.e. four situations in all). These results are given in terms of vibration energy and sound power levels, and a comparison is made between tracks in four situations. Theoretical predictions show that multiple wheels and rail absorbers have significant effects on the rail receptance, the wheel—rail interaction force, and the vibration decay rate along the track. In addition, the influence of multiple wheels on the energy and noise is limited, whereas that of the rail absorbers is notable. The rail component of rolling noise can be reduced by 7.3 dB(A) by using the rail absorber. However, multiple wheels have a slight effect on the rail radiation.