ABSTRACT
This chapter compare two well-known semi–analytical methods to analyse infinite periodic structures. The one method uses a generalized Fourier approach for the infinite periodic structure, the other uses Floquet's theorem and takes only one section into account. The calculations for a discretely supported, undamped rail show that both methods produce similar results. Analysis of the dynamical response of infinite periodic structures can be treated in various ways. In order to compare these two approaches, a rail discretely supported on sleepers without damping was calculated by both the generalized Fourier approach and using Floquet's theorem. The aim was to obtain critical frequency–velocity combinations for a harmonically oscillating, moving load, where the vertical displacements of the rail become infinite. Finally, the chapter considers possible applications to related problems. For reasons of clarity only the general procedure of both methods is given.
