摘要
单层网壳结构是缺陷敏感结构,经截面优化设计的单层网壳结构对初始几何缺陷分布形式更加敏感.在多种缺陷分布形式下,对截面优化后的网壳模型进行双重非线性整体稳定性分析,研究杆件截面取值与缺陷分布、结构极限承载力之间的关系.结果表明:截面优化寻优结果与初始几何缺陷分布有直接关系,增大缺陷较大处杆件截面能显著提高结构承载力;经截面优化设计的网壳仅在其设计初始几何缺陷下稳定承载力满足设计要求,在其他缺陷下承载力均下降明显.本文对这一现象进行了深入的研究,并通过优化"杆件分组"的方式改进了由截面优化设计导致的结构稳定承载能力对缺陷分布的高度敏感性,提高了结构整体稳定承载力的鲁棒性,同时降低了结构的耗钢量.
Single layer reticulated shell is a sensitive structure to imperfection,carrying section optimization to it has further aggravated the problem.In order to study the link between section size,imperfection position and bearing capacity of stability of structure,we perform an elastic plastic stability analysis on shell models that have been carried out section optimization under three varieties of imperfections.Analysis results indicated that there is a direct correlation between section optimization results and initial geometric imperfection distributions,and increasing cross-section size of the rod where the initial geometric imperfections are bigger will effectively enhance the ultimate bearing capacity of stability.For shell models that carried out section optimization,the bearing capacity is desired at designated imperfections,however,that does not come off at other imperfections.We made a thorough analysis of this problem and proposed a new strategy of bars group to improve its high sensitivity of ultimate bearing capacity of stability for geometric imperfection distributions partially caused by section optimization.Through this improvement,shell robustness of bearing capacity is enhanced accordingly.Meanwhile,it further lowers the consumption of steel.
出处
《空间结构》
CSCD
北大核心
2016年第2期16-21,43,共7页
Spatial Structures
关键词
网壳结构
初始几何缺陷
截面优化设计
缺陷敏感
极限承载力
reticulated shell structures
initial geometrical imperfections
section optimization
imperfection sensitivity
ultimate bearing capacity
