Wheelset-Track Dynamic Interaction Modelling with Frequency- and Preload-Dependent Stiffness and Damping of Resilient Track Components

Resilient track components are widely used in the modern railway tracks, such as the rail pads, the sleeper pads, the continuous support of the embedded rail system (ERS), etc. Track components made of resilient materials usually possess non-linear dynamic properties. In the present work, the equivalent stiffness and damping of an ERS are characterised in function of preload and frequency through laboratory tests and show an obvious non-linear behaviour. A non-linear rheological model of unit length of the ERS is identified according to the experimental data. The good agreement between the identified and experimental equivalent stiffness and damping proves the rheological model an appropriate way for the modelling of the non-linear properties of the ERS. The rheological model is subsequently integrated into a 2D track model of wheelset-track dynamic interaction simulation. The simulation related to a wheelset passage is performed and the results are compared to the ones obtained with a linear track model. The system responses obtained with the linear and non-linear track models are considerably different from each other. The results imply that the non-linear dynamic properties of resilient track components should be carefully analysed and accounted for in the train-track dynamic interaction when an accurate prediction of the system response is desired.