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Reducing the rail component of rolling noise by vibration absorber: theoretical prediction

Abstract A compound track—absorber model is employed to study the performance of a rail vibration absorber in reducing the rail component of rolling noise. The rail vibration and radiation due to a roughness excitation are calculated with the use of the absorber. Different types of rail absorber and installation locations are considered in calculations to investigate their influence on the absorber's performance. The theoretical predictions show that the rail-radiated noise can be reduced by about 6—8 dB(A) using the rail absorber for the situation modelled here. The most appropriate installation place for a discrete absorber is at mid-span between sleepers because the vibration response there is large. As the rail vibration amplitude is small at sleepers, they are not the appropriate installation place for a discrete absorber to reduce rail radiation via energy dissipation. It should be noticed that the performance of the rail absorber is predicted under idealized conditions, and the noise reduction that can be achieved using the absorber is dependent on some practical factors, which are not further studied in this work.