索支撑柔性摩天轮结构抗倒塌性能分析

Collapse resistance behavior of Ferris wheel with stay cables

研究了稳定索以某种模式失效时摩天轮结构的动力响应,考察是否会引起其他稳定索的连续失效,导致结构丧失侧向刚度而倒塌。通过动力分析得出,结构侧向位移和索力变化周期与该摩天轮结构的第一阶自振周期T1相近,且稳定索失效后0.5 T1时,索回弹动力效应对摩天轮结构的影响最显著;稳定索在失效模式FM3-1(单侧3根稳定索失效)下,索回弹动力效应对摩天轮结构影响最大,且一侧稳定索最大索力达到64%的破断力,另一侧稳定索几乎处于松弛状态;在任一稳定索失效模式下,都不会造成其他稳定索的破断继而发生连续性破坏,此类大型柔性摩天轮结构具有抗倒塌性能。

The dynamic responses of an actual Ferris wheel system induced by failure of some stay cables are investigated.Whether the failure of some stay cables can cause further failure of other stay cables,or lost of the lateral stiffness of the wheel,even collapse is discussed.Constructive results are obtained by means of dynamic analysis.The variation periods of the lateral displacement of the wheel and the stay cable force are almost equal to the first natural vibration period（Tl）of the wheel.It is about half of Tlafter the failure of the stay cables,the effect of the resilience of the failure stay cables on the dynamic behavior of the wheel becomes obvious and reach to an upper limit.The predominant failure model is the failure of three stay cables in one side at the same time.In this situation,the maximal tension force of the stay cables laying in one side reaches 64% of it breaking force;while the stay cables laying in the other side are almost in slack state.In conclusion,any specific failure mode of the stay cables would not cause the further failure of other stay cables,which might result in collapse of the wheel.Numerical results show that the collapse resistance of the Ferris wheel is strong enough.