向心关节索杆体系弦支穹顶张拉模拟分析

Numerical simulation of prestressing construction of suspen-dome structure with radial spherical plain bearing

将向心关节索杆体系应用于弦支穹顶结构中,改变以往张拉环向索通过环向拉索滑动传递预应力的方式,利用撑杆的转动位移建立预应力,避免环索与节点摩擦出现预应力损失的问题。以东亚运动会团泊自行车馆弦支穹顶张拉分析为例,采用有限元分析软件ANSYS进行施工放样态正分析找形和反分析找形,得到了结构张拉前的放样态。结果表明,反分析找形对于该类索杆体系放样态找形更加有利。经反分析找形,最终采用混合张拉方式,即先预紧径向拉杆,再张拉环向索。对张拉过程进行了全程模拟,得到张拉过程中张拉力及网壳位移控制值,获得设计预应力态。

In order to avoid friction loss of loop cable,cable-member systems with radial spherical plain bearing was induced in suspended dome which built prestress on loop cable by the rotation of strut.It differs from the traditional loop-cable prestressing method in which prestress is built through the slip of the loop cable.In this paper,the suspended dome of the Bicycle-Gymnasium for East Asian Games was taken as the research subject.Forward analysis of form-finding and back analysis of form-finding were carried out using ANSYS and the lofting state of the structure before tension was obtained.It is proved that back analysis is more suitable for finding lofting state of cable-member systems with radial spherical plain bearing.A mixed tension method is used according to above-mentioned analytical result,which prestresses radial cable firstly and loop cable secondly.By simulating the whole process of prestressing construction,pre-tension force and nodal displacements are obtained.