On the critical points of vertical vibration in a railway vehicle

Abstract

This paper evaluates the level of the vertical vibrations in a railway vehicle carbody generated by the track irregularities and examines the position of the critical point from the comfort perspective. The issue is reviewed on the basis of both a .,rigid carbody" model and a .,flexible carbody" model, which considers the first two carbody bending modes. The model errors are calculated as a function of the speed behaviour, and the results prove that the comfort performance of a railway vehicle evaluated on the .,rigid carbody" model basis are overestimated compared to the ones derived from the implementation of the .,flexible carbody" model, mainly at the centre of the carbody. Similarly, a correct estimation of the critical point position in the level of vibrations requires the modelling of the structural vibrations of the vehicle carbody.