大型柔性摩天轮轮辐索预张力确定方法研究

以北京朝天轮结构设计为背景,通过分析确定轮辐索预张力需考虑的因素,给出了确定大型柔性摩天轮结构轮辐索预张力的方法,包括预张力值域的确定方法及其调整方法,在值城范围内调整预张力需考虑的各种因素,及估算合理预张力的简便算法.指出轮辐索预张力值域上限由180度索是否满足轮辐索安全系数确定,值域下限由0度索是否松弛确定;减小轮缘自重或适当减小轮辐索的安全系数可增大值域范围,而增大轮辐索截面积可能引起调整预张力的恶性循环;轮辐索预张力的确定还需考虑轮缘平面内外的刚度及90度索的松弛;由于轮辐索预张力和轮缘自重的比值R可大致决定结构的受力特性,故大型柔性摩天轮结构可采用与北京朝天轮相近的R值初步预估轮辐索预张力值.

Spoke Cable Pre-stress Determination of Large Scale Flexible Ferris Wheels

This paper provided a practical method to decide the reasonable spoke cable pre-stress for flexible Ferris wheels. By analyzing the factors influencing spoke cable pre-stress, this paper proposed a method to determine pre-stress value range and a method to adjust the value range, pointing out that the lower limit is determined by the slack of the 0 degree cable, and the upper limit is controlled by the safety factor of the spoke cable. The reduction of wheel weight and spoke cable safety factor can both expand value range, but the increase of spoke cable section area may cause a vicious cycle in spoke cable pre-stress adjustment. Other factors affecting spoke cable pre-stress, including wheel rigidity and cable sag, were also analyzed. Besides, since the mechanical property of flexible Ferris wheels can be generally decided by the ratio R of spoke cable pre-stress and wheel weight, flexible Ferris wheels of different scales can take similar R value as Beijing Great Wheel to decide an approximate pre-stress value.