EVALUATION OF TRACK’S VIBRATION AT HIGH SPEED

This article proposes an analytical method of assessment of track’s vibration level, based on the spectral decomposition of functions of sleeper deflections under the influence of passing axles of rolling stock. Train is considered to be formed from vehicles of the same type and of unlimited length. Vibrations are studied within a stable system of coordinated, related to the ground, for one sleeper during the passage of a train of unlimited length through track’s cross section. The computational scheme takes into account vibration damping of a track, considered as an infinitely long beam on a viscoelastic foundation. The algorithm and the results of numerical calculation of track’s vibration are given at speeds in the area of conventionally critical speed (the speed at which the model that does not take into account energy dissipation on the way predicts vibrations of unrestricted amplitude).
It is shown that when the train’s speed is equal to conditionally critical (of about 500–600 km / h), the track’s vibrations reach their peak in the whole frequency range. Results are obtained for a wide frequency range from 16 to 32000 Hz in 12 octave bands in decibel scale. Methods, outlined in this article, make it possible to solve problems of accumulation of residual track’s deformations, as well as give direction for solving problems associated with the vibrations of the roadbed.

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