Investigation into mechanism of initial rail corrugation formation at a curved track

Abstract

The mechanism of initial rail corrugation formation at a curved track is analyzed with a numerical method.The numerical method considers a combination of a coupling dynamic model of a half railway vehicle and a finite length curved track,Kalker's theory of three-dimensional elastic bodies in rolling contact,and a material wear model.The Hertzian contact non-linear spring with a unilateral restrain and the non-linear tangent creep-force model by SHEN-Elkins-Hydrick are used to couple the vehicle model with the track model.Through the detailed analysis on the dynamic behavior of the vehicle curving and the transient contact geometry of the wheelset and track,the normal forces,the creepages,the contact point positions,and the contact geometry parameters of the wheels and the rails are obtained.According to the known numerical results the rolling contact behavior of the wheels and the rails, and the wear volume of the rails are calculated by means of Kalker's theory and the material wear model.In the calculation,the rail corrugation initiation at different positions of the track is considered.The numerical results show that the wavelengths and the wave-depths of the corrugations caused by the four wheels of the same bogie are different when the vehicle passes th rough the curved track.Also the patterns of the initial rail corrugations at the different positions of the track are different.The wavelengths of the corrugations are related to the wavelengths of the contact vibration of the wheels and the rails.The passing frequencies of the corrugations comprise the sleeper passing frequency and the excited resonant frequencies of the track.