Abstract
Periodic structures exhibit unique band gap characteristics by virtue of which they behave as vibro-acoustic filters thereby allowing only waves within a certain frequency range to pass through. In this paper, lateral and vertical flexural wave propagation and vibration control of a railway track periodically supported on rigid sleepers using fastenings are studied in depth. The dispersion relations in both lateral and vertical directions are obtained using the Floquet-Bloch theorem and the resulting dispersion curves are verified using finite element models. Afterwards, tuned mass dampers (TMDs) with different mass ratios are designed to control vibrations of the examined rail in both the directions. Moreover, the influence of damping of rail and resonators on band gap characteristics is investigated. As a replacement to the conventional TMD, a novel possibility to control vibration relies on using another existing rail as a lateral distributed resonator (LDR). Although the effectiveness of LDR is lower than that of localized resonators, the former represents a simple and promising way to control vibrations. Efficacy of the proposed control methods is finally verified by applying a random Gaussian white noise input. The study presented here is useful to understand the propagation and attenuation behavior of flexural waves and to develop efficient and novel vibration control strategies for track structures.
Highlights
In the context of passive control, vibration in a structure can be reduced through different mechanisms
The effectiveness of the optimized localized resonators in both lateral (LLRs)/lateral distributed resonator (LDR) and vertical localized resonator (VLR) is verified by imposing a random Gaussian white noise excitation as input
The dispersion relation for the propagation of both Wave #A and Wave #B in an infinite periodic track was formulated by means of the Floquet-Bloch theorem, and the resulting dispersion characteristics were compared with finite element (FE) models
Summary
In the context of passive control, vibration in a structure can be reduced through different mechanisms. In the context of railway tracks, different realizations of TMDs exist[33,34,35,36,37] Most of these systems employ attaching masses on either side of the rail which are allowed to deform in both the lateral and vertical directions. The dispersion relation that characterizes wave propagation in the rail is derived using the Floquet-Bloch theory of periodic structures and is subsequently verified by a finite element (FE) model This may not be effective as both the rails vibrate with the Scientific Reports | (2021) 11:18145 |
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