Abstract: The mechanism of rail corrugation, of which the wavelength is 125-160 mm, on tight curved track in metro line is investigated. Filed observations and measurements are conducted and the possible reason of the corrugation is analyzed according to the theory of track structure dynamics. Then a three-dimensional numerical model of the track structure is established by using finite element program ABAQUS and it was used to analyze the model shape and frequency response characteristic of the track structure. At last it is adopted to explore the relationship between rail corrugation and dynamic characteristics of the track. The effect of unsprung mass on the track response and the cause of corrugation are studied. The simulated results are in pretty good agreement with the measurement results. Numerical results show that the resonant frequency in the band of 60-80 Hz of the track structure, in which the rail and slab vibrates with the subgrade in vertical direction, is the underlying cause of the 120-160 mm wavelength corrugation. The anti-vibration performance is poor since the sleeper of the track is directly embedded in the slab. The corrugation results from the vertical bending vibration of the track structure when the vehicle passes over.

Key words: Rail, Corrugation, Fixed-dual short sleepers, Slab