Influence study of rail geometry and track properties on railway rolling noise

Wheel/rail interaction generates an excitation due to the roughness present on the surface of both components that produces vibration and consequently rolling noise. In this work, the railway track properties that most influence rolling noise are identified and this influence is analysed to reduce noise emission. The acoustic calculation methodology consists of characterizing the wheel using finite element techniques and the track using periodic structure theory. The influence of the track properties on the sound radiation is analysed by means of statistical techniques applied to the acoustic power results of different track configurations. To achieve this, the rail cross-section geometry is parameterized and numerous simulations are carried out by modifying these geometric parameters and the viscoelastic properties of the track components. Considering the contribution of the wheel, rail and sleeper, the results obtained indicate that the total radiation can be reduced by up to 7.4 dB(A) through an optimal combination of the track design parameters, compared to the worst combination found. In particular, the rail pad stiffness is shown to be the most influential parameter in the sound radiation.