Abstract:

The mechanism of rail corrugation on 350 m tight curves of ladder-type sleepers’ track is investigated. Field observations and measurements are conducted. The characteristics of corrugation are obtained. The dominant wavelength is 60-100 mm and the minor wavelength length is 30 mm. The vehicle speed is approximately 37 km/h. The corrugation-related frequency bands of the dominant and minor wavelength are 110-180 Hz and 324 Hz, respectively. The possible reason of the corrugation is analyzed according to the theory of track structure dynamics. A three dimensional finite element method(FEM) track model is established and it is utilized to analyze the relationship between rail corrugation and model shape and resonance frequency. The preliminary explanation of corrugation formation is obtained. The cause of corrugation is studied according to the response of track under the excitation of white noise. The theoretical results are in good agreement with the field measurements. The obtained results show that the vertical and lateral bending vibration of rail relative to the ladder-type sleepers can be easily excited when the vehicle passes the track. They exacerbate the wheel-rail stick-slip vibration and at last accelerate the formation and development of rail corrugation on curves of this track.

Key words: frequency, rail corrugation, resonance, vibration, ladder-type sleepers