Vector Form Intrinsic Finite Element Method-Based Dynamic Analysis Of Wind-train-rail-bridge Interaction System

With the rapid development of the high-speed railway in China,the operating speed of the train has been continuously increased,and the span of railway bridges has continuously increased to cross valleys,riversv,lakes,and seas.Bridges with large spans are more vulmerable to cause large vibration and deformation under the combined effect of high-speed train and strong wind.Therefore,the safety of bridge may be hindered and the stability and safety of train may be affected.In this work,the vector form intrinsic finite element method(VFIFE)is applied to establish system models for train,train-rail-bridge,and wind-train-rail-bridge.Then,the coupled vibration of wind-train-rail-bridge,the vibration performance of bridge,and the running safety and derailment of the train are investigated under wind loads.Details of this study are mainly summarized as follows:(1)The planar system model is proposed for the train-rail-bridge interaction analysis based on VFIFE method.The resonant behviors of bridge and train are studied.(2)A three-dimensional model of the vehicle-rail-bridge system is constructed considering the coupling effect using VFIFE method.A wheel rail contact model is established considering the geometry relationship and interaction force between wheel and rail.The dynamic responses of three-dimensional train-rail-bridge interaction system are analyzed.(3)A dynamic analysis platform for the three dimensional model of the wind-train-rail-bridge system is established.The static wind force and buffeting wind force are exerted on the bridge and train.The vibration of the cable-stayed bridge under the wind force and vehicle force is studied.(4)For a double-span cable-stayed bridge composed of steel and concrete,the influence of wind speeds,vehicle speeds,and the consideration of the coupler linkage on the vibration characteristics of the train-rail-bridge system are studied using the developed analysis platform.The two-dimensional derailment analysis diagrams of the "wheel-set—position" of train are plotted to study the derailment possibility of the train under wind load.The train-rail-bridge system model considering the effect of coupler based on VFIFE method not only can effectively simulate the vibration of the train-rail-bridge coupling system under wind load,but also can analyze train derailment based on the dynamic relative displacement between the wheel and rail.It is shown that the vibration of bridge can continue to increase when the train moves on a muti-span bridge with the resonant speed.Considering the influence of the coupler,the vehicle and the bridge may have a "dual-resonance"phenomenon.When a train is running on a long-span bridge,the derailment coefficient;rate of load reduction,and lateral force of the wheel-set can increase with the increase of wind velocity and vehicle speed.Some wheel-sets of train can jump at the junction of prestressed concrete and steel girders with the increasing of wind velocity or train speed.In the example analysis,derailment may occur at cars behind the train when the vehicle speed is 300km/h and the wind velocity is 25m/s.It is showed in the derailment analysis of the train on a long-span bridge that the coupler between the cars can improve train safety.