钢框架结构基于变形性能的实用高等设计方法

Deformation performance-based practical advanced design method for steel frame construction

摘要:

为了研究高层钢框架结构在正常使用极限状态下的变形性能,应用有限元软件对30层钢框架进行了全过程分析．采用蒙特卡罗法考虑了结构整体和单个构件的随机初始缺陷,通过概率统计得到了框架变形的概率密度函数,并比较了多种规范分析方法．结果表明:考虑随机初始缺陷的框架变形接近于无缺陷框架的结果,初始缺陷对结构非线性影响很小,在分析中可以不考虑;二阶分析的柱顶侧移比一阶变形增加很多,在高等设计时应根据二阶变形判断结构位移是否满足正常使用极限状态的要求．由此提出一种实用的基于变形性能的钢框架结构高等设计方法．

Abstract:

To investigate the deformation performances of high-rise steel frame structures in the serviceability limit state, full-path analyses was carried out for 30-story frames using finite element method, in which the random distribution of initial geometric imperfections in structural system and its individual members were taken into account by Monte Carlo method, and the probability density functions of the structural deformations were gained in probability statistics terms. The results indicate that the effect of the random initial imperfections on the frame deformations is so small that it can be neglected in the advanced analysis. Moreover, since the deformations at top of columns obtained from the second-order analysis are much larger than those from the first-order analysis, the second-order deformations should be used to estimate whether they meet the requirements of the serviceability limit state in the advanced design. A deformation performance-based practical advanced design method is proposed accordingly.