随机缺陷模态法在弦支穹顶稳定性计算中的应用  

APPLICATION OF RANDOM IMPERFECTION MODE METHOD IN STABILITY CALCULATION OF SUSPEN-DOME

作　　者：郭佳民[1] 董石麟[2] 袁行飞[2] 

机构地区：[1]上海海事大学海洋环境与工程学院,上海200135 [2]浙江大学空间结构研究中心,浙江杭州310027

出　　处：《工程力学》2011年第11期178-183,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50638050;51108259);上海高校选拔培养优秀青年教师科研专项基金项目

摘　　要：初始几何缺陷对弦支穹顶的稳定性能有较大的影响。在结构整体稳定性计算中,利用随机缺陷模态法为结构施加合理的初始几何缺陷是该文的主要研究目的。首先采用一致缺陷模态法,在不同初始几何缺陷下,对肋环2型弦支穹顶结构进行稳定性能分析,然后讨论随机缺陷模态中方差的取值方法,并利用该方法对肋环2型弦支穹顶结构进行了210种不同初始几何缺陷下的稳定性能分析,两种分析方法所施加缺陷的最大值均为结构跨度的1/300。分析结果表明:结构的初始几何缺陷对结构的稳定性能影响较大,考虑初始几何缺陷后结构稳定性能为完善结构的50%左右,且采用一致缺陷模态法时也需通过考虑不同缺陷分布形式的多次计算才能合理评估结构的稳定性能,建议在跨度较大、较为复杂的结构中采用随机模态法来考虑初始几何缺陷对结构稳定性能的影响。Initial geometrical imperfections affect the stability of a suspending-dome obviously. To apply theproper initial geometrical imperfections to a suspen-dome through a random imperfection mode method during calculating structural stability is the main purpose of this paper. Firstly, the overall stability of a rib type 2 suspen-dome, considering different initial geometrical imperfections, was analysed through the consistent imperfection mode method. Then, how to select the variance value in the random imperfection mode method was discussed, and at the same time, the overall stability of the rib 2 type suspen-dome considering 210 types of initial geometrical imperfections were analysed through the random imperfection mode method, the magnitude of the imperfection considered is all 1/300 span. Results show that the structural stability is sensitive to initial geometrical imperfections, the stability factor considering initial geometrical imperfections is about fifty percent of perfect structure. When the consistent imperfection mode method is selected during calculating structural stability, the structural stability is probable to estimate by some times of calculations considering different initial geometrical imperfection distributions. Thus it is proposed that the random imperfection mode method could be adopted to calculate structural stability according to the initial geometrical imperfections when the structure has a large span and a complicated form.

关 键 词：弦支穹顶 初始几何缺陷 随机缺陷模态 稳定 6西格玛 

分 类 号：TU394[建筑科学—结构工程]