冷成型钢轴压构件畸变屈曲承载力计算公式研究  

Research on design formula of distortional buckling capacity of cold-formed steel columns under axial compression

作　　者：周绪红[1,2] 何子奇[1,2] 

机构地区：[1]重庆大学,重庆400045 [2]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《土木工程学报》2015年第2期1-9,共9页China Civil Engineering Journal

基　　金：国家自然科学基金(50978128,51308272);兰州大学中央高校基本科研业务费专项资金(lzujbky-2013-m01)

摘　　要：对Hancock提出畸变屈曲承载力计算的两条强度曲线公式背景和试验基础进行了研究,并将现行北美规范、澳洲规范及我国行业标准《低层冷弯薄壁型钢房屋建筑技术规程》轴压构件畸变屈曲承载力计算公式与Hancock两条强度曲线之间的关系进行分析比较。在此基础上,建议畸变屈曲承载力有效宽度计算的修正公式,并将其与Hancock两条强度曲线进行比较。此外,采用最近的复杂形式卷边槽形截面的试验结果,对上述3个畸变屈曲承载力计算公式进行分析评价和预测准确性验证。结果表明:Hancock两条畸变屈曲承载力计算曲线为各国现行规范的直接强度法和有效宽度法而采用,但二者在部分区段有一定误差;建议的修正公式基本处于两条计算曲线之间,延伸了适用范围并减小了误差,解决了不同规范的较大计算差值,与直接强度计算结果吻合更好;建议的修正公式和现行规范的2个计算公式均能较好地预测板件中间加劲、边缘二次加劲等复杂截面形式轴压构件的畸变屈曲承载力。The formula and tested data concerning the two strength curves proposed by Hancock are studied,for predicting the load-carrying capacity of distortional buckling. A proposed design formula,and the two strength design curves are then compared with the current design methods including Direct Strength Method and Effective Width Method,employed by North American Specification( AISI-NAS: 2007),Australian Standard( AS / NZS 4600: 2005),and Chinese Technical Specification( JGJ 227—2011) on distortional buckling of cold-formed steel column under axial compression. The three design formula are then evaluated and validated for those cold-formed steel specimens with intermediate stiffeners and complex edge stiffeners. The results indicate that the current design standards adopt the two strength design curves of DSM and EWM respectively,and have some difference at partial extent. The new formula is proposed to solve this problem,which agrees better with the DSM design formula than the existing EWM design formula.The proposed EWM,the current EWM and DSM are all well to predict the load-carrying capacity of cold-formed thinwalled steel channel columns with complex cross-section experiencing distortional buckling under axial compression.

关 键 词：冷成型薄壁钢柱 畸变屈曲 屈曲后强度 极限承载力 计算公式 

分 类 号：TU392.1[建筑科学—结构工程]