Research On The Stability And Seismic Behaviors Of Cable-Supported Truss Structures

ABSTRACT: The cable-supported structure is a new type of spatial structure of tension system and it is generated on the basis of summarizing the merit and demerit of cable-stayed structure and suspended structure. The cable-supported structure refers to the cables, uninterrupted and sliding, holding structure from the bottom of the structure. Contrasted with the cable-stayed, the horizontal force of cable-supported structure is effectively reduced, for the sake of reasonable bearing force, high cable utilization, safety and economics.Basing on the finite element analysis program ANSYS11.0 in this paper, the cable-supported joint system is simply considered by coupling freedom of nodes between the cable and the truss bracket in the normal direction, and friction loss is simulated by variable stiffness spring elements. On this basis, the finite element analysis model of cable-supported truss (CST) structure is built, the stability and seismic behaviors of CST structures is researched.The main contents of this study are as follows:(1) mechanical characteristics and mechanism of cable-supported truss structure are discussed, And measures of reducing friction loss of the cable-supported joint system and the methods which make the cable uninterrupted are summarized.(2) The eigenvalue buckling and nonlinear buckling of CST structure are studied by the finite element analysis model of CST structure, and are made contrast with stability of truss structure. In the process, effects of the parameters (prestress level, cable angle, cable areas and location of cable supported joints) on calculation of stability are studied.(3) Effects of prestress level and cable angle on dynamic property and seismic behaviors of CST structure are studied. Also, force of chord and web member is calculated by time-history method.Results show that compared with the truss structures, the stability of CST structures significantly improves, and the angle of cable exerts a greatly influences on the stable bearing capacity of CST structures. The time-history analysis results show that a suitable prestress level value and cable angle value can effectively reduce the earthquake response of the structure. Basing on the above analysis results, this paper gives Suggestions of structure prestress level and cable value, which can be helpful to the further research of CST structure system.