Research On The Performance Of The Telescopic Integrated Device At The End Of The Long-Span Cable-Stayed Bridge Of The High-Speed Railway

The beam end telescopic integrated device provides a good continuous support for the rail through the joint expansion of the beam joint,the beam end telescopic device and the rail expansion adjuster,which is beneficial to adjust the longitudinal relative deformation between the long-span bridge and the approach bridge.An important technology to ensure the safety of long-span bridge lines.The beam-end telescopic integrated device is composed of an upper-support beam-end telescopic device and a rail telescopic adjuster.Its structure is relatively simple,and the daily maintenance is convenient.Therefore,it is of great significance to study the performance of the upper beam end telescopic integrated device of continuous long-span cable-stayed bridges in service and its vehicle walkability,and to determine its reliability.This paper takes the Zheng-Ji Railway Changqing Yellow River Extra Large Bridge using the beam-end telescopic integrated device as the research background,uses ANSYS finite element software and UM dynamics software to carry out the vehicle-bridge coupling simulation,and determines the safety performance of the beam-end telescopic integrated device by different factors.and the impact of the train dynamic response.The main research results of this paper are as follows:(1)Establish the refined finite element model of the long-span cable-stayed bridge and the beam end telescopic integrated device.According to the meteorological data and structural characteristics,the cable-stayed bridge and the approach bridge are carried out under the conditions of temperature rise and fall and the maximum beam end angle.Calculated and studied the telescopic performance of the beam end telescopic integrated device,and obtained the corresponding vertical and lateral deformation of the rail.(2)The UM software is used to establish the eight-section marshalling high-speed train set model and track model,and the fixed interface modal synthesis method is used to establish flexible bodies such as bridges and beam-end telescopic integrated devices.According to the wheel-rail contact relationship,the train system,track System,bridge system coupling.The key cross-section of the rail telescopic adjuster is generated by the Bspline interpolation method,and then the UM multibody dynamics software is used to generate the variable cross-section track of the rail telescopic adjuster.The most unfavorable deformation of the track is selected to be superimposed on the track irregularity spectrum as the irregularity excitation of the dynamic simulation.(3)According to the specification,the evaluation index of the vehicle-bridge end coupling system is determined,and the dynamic response of the train on the safety performance and driving stability of the beam-end telescopic integrated device under different vehicle speeds,temperatures,beam-end rotation angles,and beam-end expansion and contraction states is studied.The telescopic integrated device can ensure the safety and comfort of the train when passing through the most unfavorable temperature deformation and the maximum beam end turning angle,and the beam end telescopic integrated device can provide sufficient stiffness in different telescopic states.