Dynamic Interaction of Vehicle-Track Coupled System Under Different Patterns of Uneven Settlement

Abstract

Ballastless track is wildly employed in high-speed railways as its high stability, low irregularity and low maintain cost. However, uneven settlement at the roadbed will impact the railway’s stability, passenger’s comfort and service life of the track. Amount of models are established to investigate the vibration under uneven settlement and suggest the control standard. However, their simplification about the interaction in settlement zone are unreasonable in some cases. In this research, a vertical vehicle-track coupled model is introduced, in which the vehicle is modeled as multi-rigid body and the track is modeled as multilayer plane beams. The model is validated by track vibration measured in Beijing-Tianjin Intercity Passenger Line. To simulate the vehicle-track interaction under uneven settlement accurately, the settlement is divided into three patterns. In contact pattern, the displacement of track-subgrade interface is assumed to be continuous in settlement zone, while in contact pattern the displacement is assumed to be discontinuous. And in partial contact model, the track-subgrade interface is consider to be partial contact in settlement zone and a proposed trail-iterate algorithm is adopted to correct the contact area and the contact force in each integral step during the calculation. Based on proposed model, the dynamic response in three patterns are introduced. Result shows that the conventional model will obviously overrate the dynamic responses when the settlement is in the scope of partial contact pattern and gapped pattern.