Rolling Contact fatigue Defects and a New Approach to Rail Material Management

Abstract

This article describes the current method of calculating the Hertzian contact stress and the corresponding shear stress occurring in the rail head at the rail-wheel contact and highlights the false sense of security that this approach creates among experts. The authors then present a method that is easy to implement in spreadsheet software and provides realistic results. In light of the results obtained, it is shown that it is not possible to prevent defects induced by the occurring stresses but only to keep them within limits by means of rail machining, which is a realistic objective, without significantly limiting the throughput capacity of the railway track. The combined effects of rail machining and natural wear cause the cross-sectional area and inertia and thus, the load-bearing capacity of the rails to decrease continuously. If the limit is exceeded, the rails may be installed again in less heavily used track sections and continue functioning. At the end of their service life, the track owner sells them as used rail scrap. If possible, recasting them as electro-steels, can significantly reduce the production costs and the amount of CO2 emitted during production.