索穹顶结构施工成形理论分析和试验研究

根据索穹顶结构由拉索和压杆组成的几何拓扑关系,提出一种新的施工成形方案——由外及里逐圈按阶段分批调节压杆长度到原长的成形方案;并采用抛物线单元建立已知原长的构件变形后节点坐标与构件内力之间的关系,在此基础上提出了一种基于动力松弛法、控制构件原长求解各阶段平衡态时杆件内力和节点坐标的理论分析方法;最后通过设计加工一直径为5 m的索穹顶模型试验对该施工成形方案的可行性及理论分析方法的正确性进行了模拟和验证。试验结果与理论计算值基本符合,表明基于动力松弛法、控制构件原长的找形分析方法是正确有效的、由外及里逐圈分批调节压杆长度到原长的施工成形方案是可行的。

Theoretical and experimental study on the construction of cable domes

Based on the geometric topology of the structures composed of cables in tension and struts in compression,a new construction scheme is proposed for adjusting the length of the struts from the outer to the inner hoop.The relationship between the nodal coordinates and the internal forces of the elements of known original length is established,and a method is proposed to find the internal force of the elements and the nodal coordinates of the structures in equilibrium state by controlling the original length with the dynamic relaxation method.A cable dome model with a diameter of 5.0m is formulated to test this theory.The experimental results are mostly consistent with the theoretical ones,which indicate that the proposed form-finding method by controlling the original length with the dynamic relaxation method is accurate and effective and the proposed construction scheme is reasonable.