Insights of the vehicle-track-girder system dynamic response changes caused by the thermal deformation of CRTS III ballastless track in the natural environment

Abstract

The regularity of the high-speed railway track plays an important factor in ensuring the stability and safety of vehicle operation. The study of the influences of the slab warping deformation on the dynamic response of the vehicle-track-bridge is of great engineering significance. Currently, in relevant research work, only the impacts of track irregularity caused by the track or bridge warping deformation on the dynamic responses are considered, but the influence of structural modal changes induced by the thermal deformation is commonly ignored. This article focuses on the temperature deformation of the CRTS III track on the elevated bridge and the deformation-induced vehicle-track-girder dynamic response changes. Firstly, based on the CRTS III slab temperature deformation monitoring experiment and theoretical analysis, the warping deformations of the CRTS III track and girder in natural environments were studied. Secondly, the deformation-induced modal changes of the track-girder were fully considered, and the dynamic response changes of the vehicle-track-girder were analyzed when the warping deformation of the slab reached the maximum. Through a comparative analysis of three scenarios: no structural temperature deformation, only track irregularity caused by the deformation, and the combined effects of deformation-induced irregularity and modal changes, it was found that the time–frequency domain variation characteristics of wheel-rail force and rail acceleration can be acceptably simulated in the case of only deformation-induced track irregularity, but the dynamic response changes of the slab and girder will be underestimated. Therefore, in the study of the dynamic responses of the vehicle-track-girder with temperature effects, full consideration should be given to the deformation-induced track irregularities and structural modal changes.