Research On Natural Vibration Characteristic And Vehicle-bridge Coupling Vibration Of Long-span Lightweight Concrete-Filled Steel Tube Arch Bridge

The emergency of the CFST(Concrete-Filled Steel Tube) bring a new vitality to the development of the history of bridge.The steel tube is filled with a certain level concrete.Due to the radial constraint of steel, the concrete filled in the steel is in the state of three dimensional stress,and then the compressive strength performance of concrete is elevated. The advantages of concrete performance encourage the arch developing toward large span and light weght.As flexible structure,dynamic performance of CFST should be given adequate attention.So dynamic analysis of CFST arch bridge is necessary. Vibration of the bridge is divided into earthquakes,wind vibration and vehicle bridge coupling vibration.With the development of bridge,the issues of interplay between the vehicle and arch bridge are more and more obvious. The article which has received help from State Natural Science Fund of China(No. 51278069),studied dynamic characteristic of half-through CFST bridge on the background of HeJiang Yangtzea river bridge.Beginning of this paper described the history and present situation of CFST arch bridge, outlined the status of research of natural vibration and vehicle-bridge coupling.And then modeling method of two finite element software(Midas civil and Ansys) were explored to compare the difference between the two models which set foundation for later analysis.As we known,natural vibration is a basic research on dynamic analysis.This paper used modal analysis to research natural vibration of He Jiang Yangtzea river bridge and the impact of changing the bridge parameters of the natural vibration characteristics.Finally,this paper used the time history analysis of midas to simulate dynamic reaction of bridge under different situations.The vehicle load was simplified into fixed force in the equable speed.Dynamic response was researched in different vehicle speed 、vehicle distance and carrying capacity.For the impact coefficient of the bridgewas also made a discussion.Conclusion which will contribute to the practical application was got in the analysis.