Studies On The Static And Stable Properties Of The Cable-stayed Space Trusses In A Gymnasium

Nowadays, cable-stayed structures are widely used in China. Compared with their common applications in civil engineering , the methods and theories which are used to analyze this kind of structures are comparatively lagging.In the paper the methods used in the analysis of stayed cable are expounded. And the static and stable properties of the cable-stayed space trusses in a gymnasium are discussed.Three methods often used in analyzing stayed cable are analytic method, equivalent two force members method and finite element method. In the paper, the analytic solution of stayed cable is deduced, and a new methodin deducing the equivalent elastic module E_eq is provided , then tangentstiffness matrixes of two force members are given.Based on the stiffness of the structures , long-span space structures are divided into three kinds —flexible structures , semi-rigid structures and rigid structrures . Cable-stayed space trusses belongs to semi-rigid structures. Form-finding lies in the analysis of this kind of structure .So ,in the analysis of the static properties of the trusses, on the basis of the process which the trusses undergo, three states—zero equlibrium state, intial equlibrium state and load equlibrium state—in the process of analysis of the trusses are defined. In the paper , the influence of prestress in the stayed cables on the static prosperities of the truss is discussed. And the linear static results of the trusses are compared with the nonlinear ones. Finally, some important conclusions are drawed.In the analysis of the stable properties of the trusses,the braces in the trusses are simplified as elastic bearing. In the paper, the influence of stiffness of the braces and the prestess in the stayed cable on the stable properties of the trusses is expounded. And the effect of the geometry defect and large deformation on the stability of the trusses is discussed. At last, some important conclusions are reached.