Short pitch corrugation on straight tracks—Practical experiences

Abstract

One possibility to reduce rolling noise is to reduce roughness excitation. The basis of the paper is measurements of profile irregularities on a test section of the track between Baarn and Amersfoort in the networks of Nederlandse Spoorwegen (NS). In one of two segments, periodic wear pattern (short pitch corrugation) appears with wavelength from 3.5 to 4 cm, whereas the second one is uncorrugated. The line is used only in one direction and mainly by passenger cars with medium speed. Starting from the measured track data, systematic calculations with the program of Müller, which is presented in a separate paper, have been undertaken. The aim is to estimate the roughness growth and to find hints about how the growth can be stopped or at least reduced. In Müller’s paper it is explained in detail that roughness growth is restricted to a wavelength range between 2 and 10 cm. Numerical results will be presented in order to clarify how different track components influence the RGG process. The model only takes into account wear as a long-term mechanism. It shall be discussed how the long-term behavior is influenced by plastic deformation, hardness variations, or different values of micro-roughness.