Stability analysis of prestressed space truss structures based on the imperfect truss element

Abstract

Prestressed space truss structures have been widely used in various public buildings in recent years. However, because of its large span, the length of its members also increases. Therefore the member initial curvature will probably affect the stability of the structure. This paper focuses on the truss element with initial geometrical imperfection under high axial load. The relation between axial force and deformation, the expression of axial tangent stiffness, and the concept of initial curvature coefficient for truss element are established. With the example of prestressed cable-stayed arch-truss structure, the influence of member initial curvature on nonlinear stability performance of the structure under various prestress values is studied. The result indicates that member initial curvature has little influence on global stiffness of the structure before buckling, but has great influence on the performance of the structure after buckling and on limit load of the structure. Under different prestress values, the limit load-member initial curvature curves are parallel and almost linear. The proposed method in this paper can be widely applied into nonlinear stability analysis of various prestressed space truss structures with large span, so that the influence of member initial curvature on structural stability can be estimated.