关于强、弱支撑判别式的商榷

DISCUSSION ON THE CRITERION FOR STRONG BRACE AND WEAK BRACE

柱计算长度系数的计算在钢结构构件设计阶段是非常重要的内容。纯框架结构与框撑结构的柱子,在计算长度系数时差别很大。对于框撑结构,GB 50017—2003《钢结构设计规范》在5.3.3-1中提出了区分"强支撑"和"弱支撑"的判别式。通过一系列算例,证明了在常见建筑结构尺度下,凡是长细比小于150的钢斜撑,按照GB 50017—2003的条文5.3.3-1都是强支撑,弱支撑很难见到。尝试分析美国钢结构规范中并不区分"强支撑"和"弱支撑"的原因,并对即将发布的钢结构新规范提出几点期望。

The effective length factor（K value）calculation for column is very important in the steel structure design phase and is very different from moment frame and braced frame.For braced frame,the criterion in 5.3.3-1of GB 50017—2003can be used to distinguish weak braced and strong braced.A series of calculation examples were used to show that all the braces whose slenderness less than 150 were defined as strong brace according to the criterion in 5.3.3-1of GB 50017—2003,it＇s difficult to find weak brace if its slenderness is less than 150.This article also tried to explain why there was no definition for weak brace and strong brace in American＇s steel structure design code.Some suggestions were also provided for the coming Chinese steel structure design code.