Dynamic displacement response of track subjected to a load moving at a variable speed

Abstract

A closed-form displacement response of track subjected to loads moving at variable speeds is proposed in this paper. The structure of the track is modeled as a Timoshenko beam of infinite length that is periodically supported by double-layer spring-damping elements. The frequency-domain displacement response of the track is simplified into the mathematical form of a summation rather than an integral. The transfer function for the track is expressed in the form of a transfer matrix. Various kinds of moving loads, such as single and series moving forces, masses and double-layer mass systems, are considered in calculations. For the verification of the theory, the displacement response of a simply supported beam subjected to masses moving at variable speeds is calculated and compared with reports in the literature on the same case. The obtained results indicate that the influence of the loads moving at variable speeds on the displacement response of the track cannot be ignored, and the displacement response of the track increases slightly with acceleration of the moving loads. Also, larger oscillations are generated by the interaction of the moving mass and the track.

Keywords

Track structure moving loads variable speed dynamic displacement analytical solution transfer function

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