冷弯型钢拼合柱局部屈曲后板组效应研究  

STUDY ON PLATE GROUP EFFECTS AFTER LOCAL BUCKLING OF COLD-FORMED STEEL COMPOSITE COLUMNS

作　　者：韩爱红 陈娇娇 李艳春 谢艳芬 HAN Aihong;CHEN Jiaojiao;LI Yanchun;XIE Yanfen(School of Civil Engineering and Communication,North China University of Water Resources and Electric Power,Zhengzhou 450045,China)

机构地区：[1]华北水利水电大学土木与交通学院,郑州450045

出　　处：《低温建筑技术》2024年第9期122-126,146,共6页Low Temperature Architecture Technology

基　　金：河南省高等学校重点科研项目(23A560011);河南省高等学校重点科研项目(22A560013);河南省重点研发与推广专项(242102321151)。

摘　　要：为明确冷弯薄壁型钢(CFS)双肢闭合拼合柱局部屈曲后板组效应,文中对18根通过ST4.8自攻螺钉将单肢C形截面及单肢U形截面构件连接而成的CFS双肢闭合拼合柱进行轴压性能试验,获得试件破坏特征和极限承载力,研究了试件受力的弹性阶段和局部屈曲后继续承载阶段的各组成板件变形情况。结果表明受力阶段前期,拼合柱发生明显的局部屈曲现象;荷载继续增加,拼合柱进入屈曲后阶段,但各组成板件之间仍然存在板组效应的影响,使得C形截面翼缘与U形截面翼缘的屈曲变形方向一致,即协调屈曲,但这种屈曲作用已不再具有线性特性。基于试验结果,对GB 50018—2016和AISI-S100—2012中直接强度法(DSM)进行了验证。由于这两种方法计算理论中均未考虑承载试件局部屈曲后非线性的受力状况,使得两种方法的计算结果均存在误差,随着高厚比的增大,GB 50018—2016计算的试件承载力逐渐偏于保守,DSM计算结果逐渐偏于不安全。To clarify the plate group effects after local buckling of cold-formed thin-walled steel(CFS)double-leg closed composite columns,this study conducts axial compression tests on 18 CFS double-leg closed composite columns formed by connecting single-leg C-shaped and U-shaped sections with ST4.8 self-tapping screws.The tests provide insights into failure characteristics,ultimate bearing capacity,and the deformation of individual plates during the elastic and post-buckling stages.Results show significant local buckling in the early loading stages.As the load increases,the composite columns enter the post-buckling phase,with plate group effects still influencing the deformation,causing the buckling direction of the C-shaped and U-shaped section flanges to align,demonstrating coordinated buckling.However,this buckling is no longer linear.Based on the experimental results,the study verifies the Direct Strength Method(DSM)as outlined in China's GB 50018—2016 and the American AISI-S100—2012 standards.The findings reveal that both methods do not account for the non-linear behavior after local buckling,resulting in errors.Specifically,as the width-to-thickness ratio increases,GB 50018—2016 becomes increasingly conservative,while DSM results become progressively less safe.

关 键 词：冷弯薄壁型钢 局部屈曲后 双肢闭合拼合截面 板组效应 

分 类 号：TU392.1[建筑科学—结构工程]