Study on Rail Corrugation Development Mechanisms

Abstract

On railway tracks, the corrugation that frequently occurs on the inner rails of sharp curves often results in noise and vibration. However, since there are no widely accepted theories on the evolution of such corrugation, nor countermeasures to prevent it, it is necessary to clarify the mechanisms governing rail corrugation development. In this study, a numerical analysis is conducted to reveal those mechanisms. More specifically, an analytical model of a two-axle bogie running on rails with elasticity is used to express the vibration characteristics of a bogie-track system. In this model, the bogie repeatedly runs on a circular track, so the front wheel runs on a rail that possesses wear caused by the rear wheel during the previous lap and the rear wheel runs on a rail that possesses wear caused by the front wheel just moments before. Hence, the wear of the rail is determined by both the front and rear wheels. This simple model provides an effective way to discuss the mechanism of rail corrugation development. The rail corrugation wavelength also depends on the natural frequency of the bogie-track system. Therefore, if the phase of the contact force fluctuation follows a wavy surface, the rail corrugation will continue to grow with each passage of the bogie. However, if bogies with different natural bogie-track system frequencies operate on rails with corrugation, the wavelength and depth of the corrugation will change. Accordingly, this study also gives numerical consideration to the effects of the distance between axles on rail corrugation development.