Suspension Bridge Cable Shape Of Main Cable Saddle Effect Analysis And Application Development With Spatial Cables

Since the 21 st century,the rising of spatial cable suspension bridge construction,but its design theory and calculation method is mainly used traditional suspension bridge design theory,the problem of insufficient accuracy appeared more and more.This article taking SongYuan TianHe bridge as the engineering background,to carry out the spatial cable,saddle groove curve and the contact relation between the main cable of suspension bridges applied research.First of all,this article introduces the main cable shape calculation theory: the piecewise linear method,piecewise parabolic method and segmental catenary method;On the basis of the elastic catenary analytic calculation formula,combined with the Newton-Raphson iteration algorithm analysis under concentrated load calculation main cable shape;At the same time also put forward the first-order optimization algorithm to find main cable shape analysis method,based on ANSYS optimization module.Then,based on ANSYS platform,complete the state of spatial cable suspension Bridges.To bridge calculation the main tower only bear axial load,so don`t simulate the main tower,with Link10 element simulation cable system and Beam188 element simulation of main girder and combined with cable shape calculation method,adopt ANSYS parametric design language developed the state of spatial cable suspension bridge calculation procedure.According to the state of spatial main cable on the both sides of IP theory points direction vector to design of main cable saddle,respectively using the inclined plane arc line and space combination of arc line,can meet the constraint of main cable and saddle curve tangent,with the design of main cable saddle circular arc curve elements,then non-stress length of main cable from the theory of IP point correction to the main cable saddle curve,can be determine the main cable non-stress processing length.Finally,for the precise calculation of the hollow cable erection shape,this article introduces the main cable saddle curve and the main cable of the simulation method of contact: fixed IP point method,fixed tangent point method,and saddle-cable element,etc;Main cable saddle known space curve and the revised main cable non-stress cable length,precise calculation of hollow cable shape using two methods: 1.the formula of elastic catenary theory as the foundation,on the cable saddle space curve iteration to find the tangent point method to solve the main cable saddle deviator displacement andhollow cable shape.2.the only compression link elements simulation saddle curve and the contact relationship of main cable,to simulation calculation of main cable saddle deviator displacement and hollow cable shape.Engineering practice shows that based on ANSYS developed a bridge calculation procedure can accurately simulate the state of spatial cable plane suspension bridge;The traditional theory of IP point method is not accurate simulation the contact relations between the main cable and saddle curve,hollow cable shape calculation error is bigger.While using in this article,two kinds of calculate method for the main cable saddle deviator displacement and hollow cable shape,can accurately simulated hollow shape and the contact relationship of the saddle curve,in order to gain high precision of hollow cable shape,and put forward the reliable calculation basis for construction control.