Dynamic analysis of vibration response of track structure considering rail pads in low-temperature condition

To analyze the impact of the temperature-dependent properties of the rail pads on the vibration response of the track structure over a wide temperature range, taking into account the frequency-dependent properties of the rail pads, firstly, through its dynamic mechanical properties test and based on the high-order fractional derivative FVMP(fraction Voigt and Maxwell mode in parallel) model combined with the principle of Time-Temperature superposition, then the frequency-dependent properties of rail pads was characterized. Then the model was applied to the vertical vehicle-track coupled system. Finally, the impact of rail pads on track vibration response under extreme low temperatures was analyzed. According to the present study for vibration response of track structure, the rail acceleration shows that the case considering frequency-dependent property of rail pads is much greater than that without considering, while the slab track and base plate shows the opposite trend, the influence of temperature- and frequency- dependent properties of rail pads on the vibration response of track structure is mainly concentrated in the medium and high frequency band. Therefore, in order to improve the accuracy of track structure prediction, it is necessary to consider the temperature- and frequency-dependent properties of rail pads.