成都某“C”形屋盖提升支架非线性稳定分析

NONLINEAR STABILITY ANALYSIS OF A C-SHAPED LIFTING BRACKET IN CHENGDU

成都大魔方演艺中心大陀螺屋盖提升支架采用较为少见的"C"形开口管桁架结构形式,为了对其稳定性能进行评估,建立了该提升支架的有限元模型,在现有相关技术规范的基础上,综合考察了结构自身的几何缺陷、荷载偏心、材料屈服等多种因素的影响,对该结构进行了非线性稳定分析。研究表明:该提升支架的失稳形式表现为边柱塔架主管压弯失稳,同时伴随相应区域的整体内倾失稳;该结构的稳定承载能力满足规范相关要求,但对几何缺陷较为敏感,而荷载偏心对该结构稳定承载力影响较小,建议在实际制作和安装提升支架时,严格控制竖向管件的垂直度以及横向管件的平直度。

An uncommon C-shaped tubular truss structure was adopted to make the lifting bracket for the roof of the main venue of Chengdu large magic cube performing arts center. In order to assess the stability of the lifting bracket,the finite element models were established. The Nonlinear stability analysis of the lifting bracket was conducted based on the relevant technical specifications,considering the influence of geometric imperfections,load eccentricity,material yield and other factors. The results showed that the form of the instability of the structure was compressionbending buckling of the main pipe of cylindrical tower,along with the overall internal instability; the stability bearing capacity of the structure could meet the standard requirements,but it was sensitive to geometric imperfections and was insensitive to load eccentricity. Strictly control of the verticality of the vertical pipe and the straightness of the horizontal pipe were suggested in the production and installation of the lifting bracket.