计算长度系数的物理意义及对各种钢框架稳定设计方法的评论  

Physical Meaning of Column Effective Length and An Evaluation of Stability Design Methods of Frames

作　　者：童根树[1] 施祖元[1] 李志飚[2] 

机构地区：[1]浙江大学土木系 [2]浙江省建筑设计研究院

出　　处：《建筑钢结构进展》2004年第4期1-8,共8页Progress in Steel Building Structures

摘　　要：本文将有侧移失稳的框架柱计算长度系数与结构力学的D值法联系 ,论证了柱子计算长度系数计算柱子抗侧刚度系数 ,通过柱子计算长度系数可以较精确地确定整个楼层的抗侧刚度。本文计算表明考虑同层各柱的相互支援对框架柱计算长度系数进行修正后 ,薄弱层柱子的计算长度系数能够得到略偏安全的精度。利用整体分析时各个柱子的计算长度系数存在的关系就可以得到所有其它非薄弱层柱子的计算长度系数 ,且同样略偏安全。通过例子发现框架层与层相互作用的一个重要性质 :层对层的支援 ,对同一层的每个柱子而言 ,获得的好处 (临界力增加 )或贡献出来的刚度 (临界荷载的减小 )具有相同的比例。本文对当前各种框架稳定性计算方法 (传统的线性分析计算长度系数法、线性分析层整体稳定计算法、结构整体稳定计算法和二阶分析法 )This paper provided a new explanation of the physical meaning of the column effective length coefficient, that is, it is a lateral stiffness coefficient of frame columns. The story lateral stiffness may be accurately predicted by using the column effective length coefficient. Through examples it is found that the column effective lengths in the weakest story of frame may be predicted with current widely applied monograph, modified considering interaction of columns in one story, with small errors on the safe side. The effective length of other columns may be obtained considering the system buckling nature.It is revealed that the buckling loads of columns in one story increase or decrease in the same proportion if story-to-story interaction is considered, compared with the buckling loads without the inclusion of the story-to-story interaction.Brief comments are made on the current design methods of frame stability,including column effective length method, story buckling and system buckling approach, and advanced analysis.

关 键 词：计算长度系数 柱子 稳定设计 框架柱 钢框架 整体稳定 薄弱层 物理意义 整体分析 方法 

分 类 号：TU391[建筑科学—结构工程] TU318