点式幕墙索桁架支撑体系结构判定分析

Analysis on the judge of cable truss system of point supported curtain wall

索桁架是指由张力索和压杆组成的、具有预应力自平衡的新颖结构体系,是点式支承玻璃幕墙采用的主要结构形式之一。结构体系的完整描述必须借助矩阵平衡理论。本文利用矩阵平衡理论把铰接杆系分成了4种体系,指出索桁架必须是超静定结构(体系Ⅲ)或静不定且动不定结构(体系Ⅳ)。索桁架是柔性结构,只有施加预应力时才能抵抗荷载。索桁架结构的刚度依靠预应力予以保证,本文对此进行了阐述。

Cable truss is the prestress equilibrium system composed by tensional cable and rod, and it is one of the main structural forms of point supported glass curtain wall. The integrated description of structure draws support from the matrix equilibrium theory. The geometric construction of rod system joined with a hinge is divided into four types by virtue of the matrix equilibrium theory. And it is pointed out that cable truss must be type Ⅲ or type Ⅳ in this treatise. Cable turss supports load only when it is exerted prestress on account of it is gentleness. Thus the stiffness of cable truss depends on prestress, which is discussed in this paper.