双伸臂巨型结构整体稳定性分析  

Stability of double-outrigger-braced mega-structure

作　　者：苏健[1] 童根树[1] 

机构地区：[1]浙江大学土木工程系,浙江杭州310058

出　　处：《建筑结构学报》2010年第12期32-39,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(50578140)

摘　　要：通过对伸臂位于顶部及中部任意高度的巨型结构进行整体稳定性分析,提出了双伸臂巨型结构中伸臂和边框架柱相互作用的独立弹簧和关联弹簧模型。推导了双伸臂巨型结构整体失稳的临界方程,通过具体算例的分析得出:双伸臂巨型结构失稳时,伸臂巨型结构层总的临界轴力与轴力在核心筒与伸臂端的边框架柱之间分布基本无关。分析还表明,伸臂结构失稳时伸臂巨型结构层之间存在较大的相互作用。将基于整体以及层的荷载负刚度理论运用到伸臂巨型结构中进行分析,研究伸臂巨型结构与普通框架结构失稳性质的异同,揭示了伸臂巨型结构在本质上更加接近于框架结构而非整体弯曲型结构。This paper analysed the buckling of outriggger-braced structures.By analyzing a simplified model of doubleoutrigger-braced structure,a model composed of independent rotational spring and relative rotational spring was proposed for the outrigger-column systems.The critical buckling equation was presented where the axial force of the core and the exterior columns may be varied.Using an example,this paper revealed that the total buckling load of each mega-story was independent of the load distribution between the core and the exterior columns.The analysis also revealed the strong inter-story interaction of the double-outrigger braced structures.By comparing the buckling of the normal frame and the double-outrigger-braced structures,and also by using the approximate buckling analysis based on the negative stiffness concept of gravity loads,which is very successful in normal frame buckling analysis,it is concluded that the the double-outrigger braced mega-structure is closer to a normal frame in its buckling behaviour,although it has a stronger inter-storey interaction than normal frames.

关 键 词：巨型结构 伸臂 关联弹簧 层失稳 结构稳定性 临界轴力 负刚度 

分 类 号：TU973.14[建筑科学—结构工程] TU311.2