Study On Mechanical Properties Of Prestressed Cable Spherical Reticulated Mega-structure Under Different Cable-laying Forms

Cable prestressed spherical reticulated mega-structure is a kind of reticulated mega-structure,which has the advantages of clear force transmission,light weight and large span.The cables and struts of cable prestressed spherical reticulated mega-structure can effectively improve the stability,bearing capacity and increase the stiffness of the structure.Therefore,the cables and struts are of great significance to the cable prestressed spherical reticulated mega-structure.In this paper,four cable laying methods are brought up to study the effect of various cable laying methods on the cable prestressed spherical reticulated mega-structure.The main contents are as follows:(1)The method of establishing finite element model and calculation are validated.And then by synthetically analyzing the stress,displacement and support reaction of beam string structure of 11 cable-laying forms,the cable-laying forms of S-3 and S-7are selected out from 11 cable-laying forms,and the two cable-laying forms and the other two are used as the cable-laying forms of cable prestressed spherical reticulated mega-structure.(2)Effects of four cable-laying forms on mechanical properties of cable prestressed spherical reticulated mega-structure are studied by comparing axial force and displacements of radial and latitudinal trusses of five structures under static load.And then the internal forces and displacements of five structures are analyzed under variable parameters,which include support type,ratio of rise to span and brace length.Through analysis,the models of three cable-laying forms with better mechanical properties are selected out,and the static stability analysis of them is carried out.The reasonable values of structural design parameters are determined through analysis,andthe reasonable values of parameters are applied to static stability analysis and dynamic analysis.(3)The load-displacement curves and the deformation nephograms of four structures are obtained by static stability analysis by adopting arc-length method.Then the ultimate bearing capacities and maximum displacements of 4 models are analyzed under variable parameters,which include initial geometric imperfections,support type,ratio of rise to span and brace length.Through analysis,the models of 2 cable-laying forms with better mechanical properties are selected out,and the dynamic analysis of them is carried out.(4)Modal analysis of model of 2 cable-laying forms and no cable form is carried out,and the first 30 natural frequencies and the first 10 modes of the three structures are analyzed.Then the natural vibration characteristics of three structures are analyzed under variable parameters,which include support type,ratio of rise to span and brace length.