Non-linear viscoelastic damping: designing tests needed for transient simulation of a rail track

Abstract

Viscoelastic materials are widely used in many industries for their ability to undergo large deformation and dissipate energy. Pads placed between rail and sleeper experience large deformation when the train passes. This is important for load distribution to the sleepers. They also strongly contribute to vibration damping, and thus to lowering noise emissions associated with rail/wheel contact. There is thus a need to have a model that allows transient simulation in a regime accounting for dependence of the behavior on time history including multiple time scales. The study revisits the design and exploitation of test sequences combining steps, ramps, stepped sine and sweeps in frequency and amplitude. Illustrations are given for full scale tests of rail-spleeper pads.