Dynamic performance of CRTS III ballastless track structure under the train load and temperature

Abstract

Due to the thermal deformation of the track structure under natural temperature, it inevitably changes the initial condition of the track, and causes significant influence on the dynamic performance of the track under the moving vehicle. This work aims to reveal the interfacial damage and dynamic behaviors of the track structure subjected to the temperature and a moving vehicle. For this purpose, a thermomechanical coupling analysis method of CRTS III is developed by loading the temperature and train load. Among them, a three-dimensional vehicle-track interaction model is established to obtain the rail-supporting force. Besides, a transient heat transfer model of CRTS III is developed by introducing the complex thermal boundary where the solar radiation and heat convection are taken into account, and thus the temperature field of CRTS III under the natural environment is obtained in a space–time scale. The dynamic behaviors of the track and interfacial damage under different temperatures, interface strength and speeds of vehicle are investigated by the proposed methodology. The results indicate that the temperature significantly influences the acceleration and displacement of the track slab, especially in the frequency range of 25 Hz–75 Hz and the response amplitudes also increase 2–6 times. The temperature is the main factor inducing interface damage instead of the train load, therefore, we should pay more attention to the interface debonding in summer.