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.

中文翻译：

---

基于不完善桁架单元的预应力空间桁架结构稳定性分析

近年来，预应力空间桁架结构已广泛用于各种公共建筑中。但是，由于其跨度较大，其成员的长度也会增加。因此，构件的初始曲率可能会影响结构的稳定性。本文重点研究在高轴向载荷下具有初始几何缺陷的桁架单元。建立了轴向力与变形的关系，轴向切线刚度的表达式以及桁架单元初始曲率系数的概念。以预应力斜拉拱桁架结构为例，研究了构件初始曲率对结构在各种预应力值下非线性稳定性能的影响。结果表明，构件初始曲率对屈曲前结构的整体刚度影响很小，但对屈曲后结构的性能和结构的极限载荷影响很大。在不同的预应力值下，极限荷载构件的初始曲率曲线是平行的，几乎是线性的。本文所提出的方法可以广泛地应用于各种大跨度预应力空间桁架结构的非线性稳定性分析，从而可以估算构件初始曲率对结构稳定性的影响。