拉索失效后的弦支穹顶结构稳定性能研究

Research on the stability of suspen-dome after cables failure

弦支穹顶是近几年迅速发展起来的一种新型空间结构体系,它是一种典型的空间型弦支结构形式.本文总结弦支穹顶布索特点,对弦支穹顶局部拉索破断失效后的结构进行了特征值屈曲分析和非线性稳定性分析,得到了不同拉索失效后的非线性稳定分析临界荷载和一阶屈曲特征值,前者小于后者但在规律上是一致的.最外圈拉索失效对弦支穹顶一阶屈曲特征值和非线性稳定分析临界荷载改变最大,表明最外圈拉索对弦支穹顶稳定性影响最为显著.最后给出了不同拉索失效情况下拉索内力分布图,揭示了某一圈拉索失效后内力重分布情况,可得最外圈拉索在不存在失效单元时索力始终最大,存在失效单元的拉索索力一般最小.这些结果为弦支穹顶结构在抗连续倒塌能力方面提供一定的基础,同时也对弦支穹顶结构的推广应用具有一定参考意义.

Suspen-dome is a newly developing space structure and typical spatial cable supported structure.This paper summarized characteristic of cable distribution in suspen-dome.The eigen value buckling analysis and nonlinear stability analysis of suspen-dome after cable failure were carried out.The buckling critical load and first order buckling eign value were obtained.The former was smaller than the latter,but they were unified.The change of buckling critical load and first order buckling eigen value was the largest if the outside cable failured.In other words,the outside cable had the biggest influence on stability of suspen-dome.Finaly,the cable force redistribution with different cable failure was obtained.The outside cable force was the largest only if it did not include the failure element.The smallest cable force existed if it included the failure element.The analytical results can provide a guideline for the relevant progressive collapse study on suspen-dome.