高强冷弯型钢C形截面短柱畸变屈曲和局部屈曲耦合的试验研究  

Experimental Research Investigation for on Cold-Formed High-Strength Steel C-Section Stub Columns with Interaction of Distortional and Local Buckling

作　　者：张佳慧 谭卓琼 ZHANG Jiahui;TAN Zhuoqiong(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093

出　　处：《工业建筑》2023年第11期188-195,共8页Industrial Construction

基　　金：国家自然科学基金项目(51508328)。

摘　　要：薄壁开口截面易发生畸变屈曲与局部屈曲,这两种屈曲模式的耦合对冷弯型钢构件的力学性能有显著影响,现有规范中的承载力计算方法未能准确地考虑这种相关作用。针对2根高强冷弯型钢C形截面短柱开展试验研究,通过改变翼缘加劲、翼板尺寸和板件厚度,考察畸变屈曲与局部屈曲的相关作用对构件承载性能的影响。与试验结果比较后发现:1)开口截面短柱的承载力计算也需要考虑畸变屈曲,2)对发生局部与畸变屈曲耦合构件,直接强度法和有效宽度法给出的承载力计算值过高。在现有直接强度法基础上,依据屈曲变形发生的先后顺序进行屈曲模式识别,得到的修正计算值能准确地预测发生屈曲耦合构件的极限承载力。Thin-walled open-section members are likely to occur distortional and failed by local buckling,and the interaction between the buckling modes will result in the deterioration of mechanical properties of loading capacity for cold-formed steel columns.Whereas,this interaction is not included properly in the design calculation of the current specifications.A test program of 2 high-strength cold-formed steel C-section stub columns was conducted.This experiment studied the relations between the flange stiffener,flange plate size,plate thickness and the buckling interactions,and their influence on the bearing capacity of compression members.The comparisons between the design strength and test results showed that:1)distortional buckling should be considered included in design calculation for the bearing capacity of stub columns;2)the direct strength method and the effective width method overestimated the bearing capacity of compression members that failed by interaction of local and distortional buckling.The buckling mode identification was carried out according to the sequence of occurrence of buckling deformation,and the modified design curves of current direct strength method were proposed for local and distortional buckling,respectively.These modifications could accurately predict the ultimate strength of high-strength cold-formed stub columns that failed by interaction of local and distortional buckling.

关 键 词：高强冷弯型钢 屈曲耦合 轴压构件 屈曲模式识别 直接强度法 

分 类 号：TU392.1[建筑科学—结构工程]