Contact and creep characteristics of wheel–rail system under harmonic corrugation excitation

Abstract

To study the wheel–rail contact and creep characteristics and the evolution law of corrugation with different wavelengths, the wave-like wear is idealized as continuous harmonic excitations consisting of three wavelengths and wave depths, and the vehicle–track space coupled dynamic model is established for specific analysis. The results show that when the wavelength is fixed and the wave depth increases, the average values of rail/wheel vertical vibration acceleration and wheel–rail longitudinal creepage/creep force increase and the average value of transverse creepage/creep force decreases. But, when the wave depth is fixed and the wavelength increases, the average values of rail/wheel vertical vibration acceleration and longitudinal creepage/creep force decrease and the average value of transverse creepage/creep force increases. Both longitudinal and transverse creepages/creep forces contain the characteristic frequency consistent with the passing frequency of initial irregularity. The characteristic frequencies of longitudinal creepages/creep forces tend to develop in the high-frequency band with the increase of wave depth, whereas the characteristic frequencies of transverse creepages/creep forces concentrate in the low-frequency band and decrease with the increase of wave depth. Under the condition of the same wavelength, with the increase of operation times, the wear amount increases slightly in the low-frequency band but greatly in the middle- and high-frequency bands, which shows that rail corrugation will gradually develop toward short wavelength corrugation at the constant velocity. When rail corrugation is formed, its development speed will gradually slow down with the increase of vehicle running times, and the development speed of short wavelength corrugation is faster than that of long wavelength corrugation.