Resilient Track Components Modelling Options for Time Domain Train-Track Interaction Simulation

Resilient components are widely used in railway tracks. For time domain train-track interaction simulation, the components are usually considered as linear Kelvin-Voigt models. However, the dynamic properties of the resilient components are often dependent on frequency and static preload, and this requires alternative methods to be adopted. The current study aims at comparing four different rheological models for the viscoelastic behaviour of the resilient components: a linear Kelvin-Voigt model, a linear three-element parameter model, a linear five-element parameter model and a non-linear three element model. Except for the linear Kelvin-Voigt, the other three models are able to reproduce the dependence on frequency, and the nonlinear three-element model can also reproduce the dependence on static preload. The rheological models are used as the foundation of the rail in vertical direction to study the effect of the different options on train-track dynamic interaction. To that aim, their effects on track dynamics are first studied in frequency domain with unit-length track models comparing the dynamic characteristics of the proposed models. Then the investigation is extended to time domain train-track interaction simulation analysing the force transmitted to the ground. Remarkable differences of the results are observed in the frequency ranges associated with the wheelset-track coupled vibration and the resonance of the track.