| China already has a huge high-speed railway network,with bridges accounting for a high proportion of high-speed railway lines.There is a very common phenomenon of pier deformation in high-speed railway bridges,which is mainly reflected in pier settlement and lateral deformation of piers.On the other hand,high-speed railway lines have strict control over the deformation of offline structures.The deformation of bridge piers leads to additional deformation of the main beams and track structures,exacerbating track irregularities,and ultimately exacerbating the coupled vibration of the train and bridge when the train passes,which affects the safety and comfort of train operation.Therefore,conducting dynamic analysis of the high-speed train track bridge coupling system considering bridge pier deformation and studying the influence of bridge pier deformation on the vibration of the coupling system has important guiding significance for evaluating train safety operation and bridge maintenance in the later stage.Based on the joint simulation platform of multi-body dynamics software SIMPACK and finite element software ANSYS,a vibration analysis model of the vehicle rail bridge coupling system considering bridge pier deformation was established.The influence of bridge pier deformation on the vibration response of the coupling system was studied through simulation analysis.Based on the calculation results,suggestions for safety control values of bridge pier deformation were given from the perspective of safety and comfort evaluation standards for train operation.The main research content is as follows:(1)Introduced the dynamic analysis method for the coupling system of vehicle rail bridge due to pier deformation.This article is based on the joint simulation platform of the general finite element software ANSYS and the multi body dynamics software SIMPACK to establish a vibration analysis model of the vehicle rail bridge coupling system considering bridge pier deformation.Firstly,establish a multi body dynamic model of the train and a spatial finite element model of the track and bridge,and input it into SIMPACK as a flexible body.By considering the impact of bridge pier deformation on the vehicle rail bridge system through additional track irregularities,and input the track irregularity samples through specific excitation types in SIMPACK.Finally,form a mechanical model of the vehicle rail bridge coupling system through the wheel rail contact relationship and beam rail connection relationship.(2)Taking a 4-span 32 m simply supported box girder bridge and an 8-car train formation as an example,the dynamic analysis model of train track bridge coupling system was established to carry out vibration simulation analysis of the coupling system,explore the basic characteristics of vehicle track bridge coupling vibration,and analyze the influence of train speed on vehicle track bridge system vibration,It can be seen that the vibration response indicators of the vehicle bridge system increase with the increase of vehicle speed,and the increase in vibration response of trains is more significant than that of bridges.(3)Conduct research on the influence of deformation direction(settlement/lateral deformation)and deformation value of bridge piers on the vibration response of train track bridge coupling system.For the settlement and lateral deformation of bridge piers,multiple working conditions such as deformation values of 0mm-50 mm were set for calculation and analysis.Research has shown that the overall impact of pier deformation on the vibration response of trains is more significant,while the impact on the vibration response of bridges is not significant.There are also differences in the sensitivity of different train vibration indicators to pier deformation.Based on the safety evaluation indicators of train vibration response,it can be concluded that when the settlement displacement of the bridge pier exceeds 21.0mm,the reduction rate of train wheel load exceeds the safety limit required by the specifications.When the lateral displacement of the bridge pier exceeds 21.5mm,the lateral force of the train wheel axle exceeds the safety limit.Therefore,it is recommended to control the settlement value and lateral deformation value of the bridge pier within 21.0mm and 21.5mm respectively. |
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