具有外环桁架的肋环型索穹顶初始预应力分布快速计算法

目的研究具有外环桁架的肋环型索穹顶的构件布置和特点,提出确定初始预应力分布的快速计算法.方法考虑到该结构是一种轴对称结构,将结构简化为半榀平面桁架,采用节点平衡理论进行分析.结果提出了确定初始预应力分布的快速计算法,得到了不设和设有内拉环的具有外环桁架的肋环型索穹顶预应力杆初始内力的计算公式,并将对特定参数的该种结构的计算结果与非线性有限元分析结果进行了对比.结论具有外环桁架的肋环型索穹顶结构是有发展前景的新型结构,内部建筑空间利用率高,外圈索的初始内力明显减小.快速计算法可方便地确定该类结构的初始预应力分布,为设计和力学性能分析提供基础.

Quick Calculation Method for Initial Prestress Distribution of Geiger Domes with Outer Truss Torus

The purpose of this paper is to investigate characters, initial prestress distribution and its quick calculation method of Geiger dome with outer truss torus. Considering the axial symmetry of the structure, the computation model can be simplified as a planar truss. With the theory of nodal equilibrium, a quick calculation method for initial prestress distribution of Geiger dome with outer truss torus was proposed. And the general equations corresponding to domes with an inner hoop and domes without an inner hoop were derived respectively. Using these equations, the initial prestress distribution of domes with certain parameters was obtained and compared with the results obtained by FEM. The conclusion is brought forward that Geiger dome with outer truss torus is a new structure with good prospect due to the high using ratio of architectural inner space and lower prestress level of outer cable. The initial prestress distribution of Geiger dome with outer truss torus can be quickly determined with the proposed method, which provides base for further design and behavior analysis of this new dome.