Influence of wheel tread surface roughness on the noise emitted by railbound freight vehicles

Abstract

The increased capacity of freight railway traffic leads to increased noise pollution. The existing regulation TSI NOI defines the maximum noise level allowed to be emitted by railway vehicles. Consequently, the noise tests are mandatory type tests for all new vehicles. Experience from noise tests of different freight wagons have shown that measured noise level depends on many parameters and in most cases is close to the maximum permissible values. Contemporary design of the freight wagons has to be conceived such as to emit as low noise as possible. Accordingly, it is necessary to identify the main influencing sources that affect the noise generation and to find a way to reduce their influence. This paper presents results obtained by measurements of pass-by noise of a freight wagon, with wheels having different wheel tread surface roughness. It appeared that wheel-rail rolling contact as a noise source is very significant and may be critical for assessment of the railbound vehicles.