Vibration energy transmission characteristics of vehicle-track coupled system considering dynamic viscoelasticity of vibration-damping pads

The installation of vibration-damping pads is the primary vibration reduction measure for slab tracks of high-speed railways in China. This study examines how the dynamic viscoelasticity of these pads influences vehicle-track vibration energy transmission. The viscoelasticity was characterized by combining the fractional derivative model and generalized Maxwell model, which were incorporated into a vehicle-track coupled dynamics model. Using the power flow method, the effects of vibration-damping pad installation, temperature- and frequency-dependent properties, and train speed on track vibration energy transmission were quantitatively analyzed. The results indicate that the neglecting frequency-dependent characteristics of the vibration-damping pads reduces energy transmission between the composite and base slabs, thereby overestimating the vibration reduction effect of the vibration-damping pads. A decrease in ambient temperature reduces vibration energy in the composite slab while increasing it in the base slab. Higher train speeds shift the vibration energy peak of the track structure to higher frequencies. Therefore, the temperature- and frequency-dependent viscoelasticity of the vibration-damping pads should be considered in the design and operation of vibration-damped tracks for high-speed railways.