葵花型索穹顶结构力学性能及拉索破断试验研究

EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES AND CABLE BROKEN OF LEVY CABLE DOME

通过对一直径6m的葵花型索穹顶试验模型,进行竖向对称加载、非对称加载以及拉索瞬间破断试验,研究了该结构的受力特点以及单根拉索瞬间破断时结构的响应特征。应用非线性有限元数值计算方法建立索穹顶计算模型,对葵花型索穹顶结构的力学性能进行了分析,并与试验结果进行比较。结果表明:在各加载阶段,节点竖向位移实测值普遍较计算结果偏大,拉索索力实测值与计算结果总体吻合较好;对称加载过程,结构的荷载-位移关系具有较好的线性规律;与对称加载比较,非对称加载的荷载-位移关系则表现出非线性,节点位移也较大,非对称荷载对结构竖向刚度的设计起控制作用;单根拉索瞬间破断时,结构会有微幅振动,不同位置拉索的失效对结构的影响程度不尽相同。

The cable dome with diameter of six meters was tested under a vertical symmetry loading, an asymmetrical loading, and the cable broken test was also made. The mechanical performance of the cable dome was analyzed based on the experimental study in the moment of cable broken. The mathematical model based on the nonlinear finite element numerical method was employed to analyze the main mechanical properties which were compared with the test results. The test results show that： the node displacement is larger than that of the numerical calculation results, and the inner forces of the cable have a general good agreement with the numeric ones; the vertical load-displacement has good relationship under vertical symmetry loading, and the load and the displacement has nonlinear relationship under asymmetric loading, thusly the stiffness under asymmetrical loading is the key of design; cable dome has vibration in the moment of cable broken, and the cable failure at different locations makes the different influence to the structure.