Study On Linear Shape And Seismic Performance Of The Wind Cable Of A Pedestrian Suspension Bridge

Currently,Suspension bridges are more and more welcomed by bridge engineers all over the world,because of their great span capacity,material saving,light weight and beautiful appearance,etc.In some scenic spots or cities,a lot of suspension bridges are emerging for sightseeing.Cable as a flexible material,it is prone to deformation under load.As a new type of structure,the wind cable system not only ensures the overall stiffness of the suspension bridge,but also takes into account the beauty of the bridge.But because of its use in the form of space curves,and the research on the theory of parallel cable plane applied in space is more lacking,it is necessary to study it.Based on the filial piety Bridge in Fengya Mountain,this paper combines the theory of stress free state and the theory of seismic resistance,which mainly carries on the following research:(1)The history and development of the suspension bridge are reviewed,and the research status of wind resistant cable and the development of seismic theory are introduced in detail.(2)The calculation theory of wind cable alignment is elaborated,and the calculation program of the wind cable alignment of the pedestrian suspension bridge is compiled by using MATLAB.The convergence problem of the traditional influence matrix method in the calculation of the spatial cable plane is optimized,and the feasibility of the algorithm is verified by the example of the filial piety bridge.(3)The pedestrian suspension bridge of filial piety bridge as the engineering background,elaborated the mechanism of wind cable system;based on the original wind cable structure,by changing the wind cable form,stiffness and initial tension,the wind cable structure is optimized;and tension scheme of the wind cable is explored.(4)The finite element software Midas civil was used to simulate the filial piety bridge before and after the wind resistant cable was applied.Through eigenvalue analysis,response spectrum and dynamic time history analysis,natural frequencies,displacements and internal forces of two kinds of bridge models are obtained,and their most unfavorable seismic responses are determined.Through comparative analysis,it can be concluded that wind resistant cable can not only raise the natural frequency of suspension bridge,improve the overall stiffness of the structure,but also enhance the seismic performance of the bridge,which can play a good damping effect in the earthquake action.