Modelling the Viscoelastic Behaviour of Elastomeric Components: An Application to the Simulation of Train-Track Interaction

The paper deals with the experimental characterisation of the frequency dependent behaviour of elastomeric track components and with the definition of appropriate models in time domain for these elements. It is shown in particular that the dynamic stiffness of elastomeric components depends on both amplitude and frequency of deformation. Moreover, the dissipative behaviour is closer to the hysteretic hypothesis than to the viscous one. Some simple models allowing to reproduce the measured behaviour of these elements are defined and a procedure for the identification of their parameters is set-up. It is shown that rather simple models can provide better results than the classical ones composed by a spring in parallel to a viscous damper. It is also shown that the introduction of these models into a finite element description of the track provides a significant improvement in the calculation of track inertance and on the results of the simulation of train-track interaction.