The Study Of The Response Of Vehicle-bridge Coupling System Under The Action Of The Wind And The Prediction Of The Bridge Fatigue Life

With the deadweight and speed of modern train having been improved, it hasmade the load and frequency of bridge structure increase continuously. And it bringsthe damage worsening for bridge. In addition, wind load has an important impact onthe bridge structure safety, vehicle operating, and even structural fatigue. Therefore,the study of the law of vehicle-bridge system coupled vibration under the action ofthe wind and the bridge structure fatigue calculation method which is under theincentives of wind are important.This paper sets up the prestressed bridge model. And based on it, we focus onstudying about the interaction in the vehicle-bridge system coupled vibration underthe action of the wind. The main research work is as follows:1In this paper, we improve the traditional bridge modeling methods which notconsiders the influence of prestress. And we use prestressed element to build bridgemodel. Finally, we check the prestressed structural dynamic model by modalcalibration.2We set up the calculation models of the vehicle-bridge coupling system underthe action of the wind; calculate the response of the system with NEWMARK valuecalculation method.Taking the beam bridge as an example, we calculate the law thatthe stationarity is low as the increasing of the speed of the wind and the vehicle, theinfluence of the crane beam’s and pier’s stiffness and the span of the bridge on thestationarity of vehicle in the vehicle-bridge coupling system under the action of thewind. We bring the improvements of bridge structure and the scheme of vehiclesrunning after analysis.3In this paper, we obtain the time history of load information by usingvehicle-bridge coupling calculation procedure. We use the improved rain-flowcounting method to screen data, combined with fatigue calculation methods ofstructural fatigue calculation to forecast the fatigue life of bridge. And we analyzefatigue properties and its laws of the arch bridge structure.4We set up a long-span suspension bridge model, and check the method ofsetting up the prestressed model and the calculation of vehicle-bridge coupling system under the action of the wind and structural fatigue. At the same time, weresearch the law of vehicle stationarity changing with the wind, bridge structurefatigue life changing with the exciting force of the vehicle and wind. What’s more, thelaw of lateral displacement of long-span suspension bridge which caused by thedifference of vehicle speed under the action of the wind in the vehicle-bridgecoupling system. Finally, we give our suggestions about the vehicle operating.