张弦巨型网格结构布索方案研究

Research on Cable-strut Arrangement of String Reticulated Mega-structure

针对由张弦梁概念和巨型网格结构组合而成的一种新型超大跨空间结构,提出了5种可能的索杆布置方案.研究了矢跨比对不同布索方案结构变形的影响,并对同一矢跨比下各布索方案结构的最大挠度、杆件内力峰值、支座水平反力、挠度和内力分布情况、稳定承载力及失稳模态等方面进行了综合分析,且与同样形式未布索结构作比较.结果表明,预应力体系的引入可以显著改善巨型网格结构的整体变形、杆件内力峰值和整体稳定承载力.在各方案中,拉索交叉的索杆对称布置于立体桁架拱跨中大部分范围(非满布)的布索方式能最有效地改善结构静力与稳定性能,为最佳方案.

For a new type of string reticulated mega-structure based on the concept of beam string structure and cylindrical reticulated mega-structure,five types of cable-strut arrangements were presented, and the influence of rise-span ratio on structural deformation in different cable-strut arrangement styles was also investigated.The maximum deflection,peak value of member internal force,horizontal support reaction,distribution of deflection and member internal force,ultimate load and buckling mode of the structure were analyzed and then compared with those of the corresponding structure without cables.The results indicate that the adoption of the prestressing system can significantly improve the structural deformation,peak value of member internal force and ultimate load.The static performance and stability of the structure can be improved most effectively when the struts and cables are arranged crosswise and symmetrically along the central wide range of span of the trussed arches,which is hereby the optimal arrangement scheme.