刚性网格索穹顶结构组合形式及其协同工作非线性力学性能研究

Static behavior analysis and combined forms of rigid grid cable dome based on cooperative work

提出了一种刚柔相济的组合空间结构-刚性网格索穹顶结构,该结构不仅充分发挥了索穹顶的力学性能,而且易于利用刚性网格铺设屋面板材,既具有结构优势又便于屋面安装。给出了肋环型、葵花型两种典型索穹顶与以四边形和三角形为基本构成单元刚性网格的3种组合形式。对刚性网格与索穹顶协同工作机理进行分析,将结构进行有限元离散和合理简化,建立了刚性网格索穹顶结构协同工作非线性静力分析的计算模型。以组合Ⅰ型为例,探讨了结构在满跨均布荷载和非对称荷载作用下内力和位移变化规律,以及初始预应力水平对结构力学性能的影响。计算结果表明:刚性网格的协同工作提高了结构整体刚度和承载力,减小了索穹顶对非对称荷载的敏感性;初始预应力水平对索穹顶内力影响显著,但对结构整体刚度影响非常不明显。

A kind of combination of flexibility spatial structure-a rigid grid cable dome was put forward ; the composite structure makes full use of mechanical characteristics of cable dome and easy assemblage of roofing material in rigid grid. Three types of composite structures combined of Geiger. Levy cable domes and corresponding rigid grid were given. The collaborative work mechanism of the rigid grid cable dome was analyzed, the rigid grid cable dome was rationally discrete and simplified, and then nonlinear static analysis model was established based on cooperative work. Correspondingly the Geiger form of rigid grid cable dome was taken as an example, and its static behavior under full span and semi span uniform load was analyzed. The effects of collaborative work of rigid grid on the stiffness of the whole structure were also studied. Numerical results show that the stiffness and bearing capacity of structure was enhanced by the cooperative work of rigid grid, and the sensibility of cable dome was decreased. The effect of the initial prestress level is significant to the force of cable dome, but is not same to the structure stiffness.