A new approach for loads moving on infinite beams resting on elastic foundation

摘要

The present work deals with the problem of the dynamic behavior of infinite beams resting on a Winkler-type elastic foundation under moving loads. The beam is subjected to a moving point load traveling with constant speed. Determining the effective length of the beam for a non-moving (static) load, and using the so-called quasi-stationary state of the beam, a solution is proposed with the aid of modal analysis and useful conclusions are obtained. Moving loads have a significant influence on the dynamic behavior of elastic or inelastic solid elements of an entire structure or parts of the structure, while they may produce strong vibrations on such systems, especially when high speeds are reached. The expressions obtained in this work allow the use of the same formulae for any values of speed or damping parameters. The analytical results obtained by the relations presented herein are compared to the ones given by Fryba in the relative chapter of his classic work. Finally, the possible speeds of moving loads that can be reached in the case of such types of beams are estimated and the application field of the gathered relations is determined.