冷弯薄壁型钢四肢拼合梁柱节点抗弯性能研究_温会平.pdf

第 20 卷 第 4 期2023 年 4 月铁道科学与工程学报Journal of Railway Science and EngineeringVolume 20 Number 4April 2023冷弯薄壁型钢四肢拼合梁柱节点抗弯性能研究温会平，刘艳芝，邓飞云，张芬芬(湖南大学 土木工程学院，湖南 长沙 410082)摘要：基于梁、柱截面拼合形式提出一种新型梁柱连接节点，以实现其拼合截面梁柱的快速装配。为研究其抗弯性能，对4组节点试件进行单调加载试验。通过试验得到节点的破坏模式、弯矩-转角关系，分析柱板厚、节点域螺钉数量、连接件端板厚度对节点抗弯性能的影响，为之后建立有效的冷弯薄壁型钢节点性能分析模型库提供数据，并对节点承载力进行理论计算。研究结果表明：该类节点的破坏模式主要有螺钉拔出或剪断、端板抗弯失效。柱板厚度增加1倍后，节点初始刚度增加26%，极限弯矩提高39.3%；节点域螺钉数量由3排(6个)增加到4排(8个)后节点初始刚度仅增加9.9%，极限弯矩仅提高6.4%；连接件端板厚度由4 mm增加到8 mm时，节点初始刚度提高45.5%，极限承载力没有明显变化。说明柱板厚和连接件端板厚度对节点初始刚度的影响较大，柱板厚对节点极限承载力也有一定的影响，而螺钉数量对节点的初始刚度和极限承载力影响不大。柱板厚度同时翻倍后，增加节点域螺钉数量可以提高节点的初始刚度和极限承载力。4组节点的弯矩转角曲线呈现明显的非线性特征，基于欧洲钢结构Eurocode3规范确定该类节点为半刚性节点。通过对节点进行受力分析计算节点极限弯矩，将计算值与试验值进行对比发现，理论计算值与试验值较为吻合。试验研究的连接件也可用于箱型冷弯轻钢梁柱连接节点，有利于快速装配。关键词：冷弯薄壁型钢；四肢拼合截面；梁柱节点；自攻螺钉连接；单调加载试验；弯矩转角(M-)曲线中图分类号：TU391 文献标志码：A 开放科学(资源服务)标识码(OSID)文章编号：1672-7029（2023）04-1445-11Flexural behavior of cold-formed thin-walled steel quadruple-limb build-up beam-column connectionsWEN Huiping,LIU Yanzhi,DENG Feiyun,ZHANG Fenfen(School of Civil Engineering,Hunan University,Changsha 410082,China)Abstract:Based on the combination of beam and column sections,a new type of beam-column connections wasproposed in order to realize the rapid assembly of the beam-column with its combination section.In order to study its flexural performance,monotonic loading tests were carried out on four groups of connections,and the failure modes and bending moment-rotation relationship of the connections were obtained through the tests.The influences of column thickness,the number of screws in the connection domain and the thickness of the end plate of the connection on the flexural performance of the connection were analyzed.This provided data for 收稿日期：2022-04-19基金项目：湖湘高层次人才聚集工程-创新人才资助项目(2021RC5005)通信作者：刘艳芝(1982)，女，湖南新化人，副教授，博士，从事钢结构、组合结构与工程结构的极限荷载研究；E-mail：DOI:10.19713/ki.43-1423/u.T20220771铁 道 科 学 与 工 程 学 报2023 年 4月establishing an effective performance analysis model library of cold-formed thin-walled steel connections,and theoretically calculated the bearing capacity of the connection.The results show that the failure modes of this kind of connections mainly include screw pulling out or shearing,and bending failure of end plates.When the thickness of the column is doubled,the initial stiffness of the connection increases by 26%and the ultimate bending moment increases by 39.3%.When the number of screws in the connection domain is increased from three rows(6)to four rows(8),the initial stiffness of the connection only increases by 9.9%,and the ultimate bending moment only increases by 6.4%.When the thickness of the end plate increases from 4 mm to 8 mm,the initial stiffness of the connection increases by 45.5%,and the ultimate bearing capacity has no obvious change.It shows that the thickness of the column plate and the end plate of the connection have great influence on the initial stiffness of the connection,and the thickness of the column plate also has certain influence on the ultimate bearing capacity of the connection,while the number of screws has little influence on the initial stiffness and ultimate bearing capacity of the connection.When the thickness of the column is doubled at the same time,increasing the number of screws in the connection domain can improve the initial stiffness and ultimate bearing capacity of the connection.The bending moment-angle curves of four groups of connections show obvious nonlinear characteristics,and this kind of connections is determined to be semi-rigid based on Eurocode3 specification for steel structures in Europe.The ultimate bending moment of the connection is calculated through the stress analysis of the connection.By comparing the calculated value with the experimental value,it is found that the theoretical calculated value is in good agreement with the experimental value.The tested connections can also be used for box-type cold-formed light steel beam-column connections,which is conducive to rapid assembly.Key words:cold-formed thin-walled steel;quadruple-limb build-up section;beam-column connections;self-drilling screw connections;monotonic loading test;moment-rotational curve 冷弯薄壁型钢结构体系有轻质高强、舒适节能、全预制化、施工便利、绿色美观、安全可靠等优点。与热轧型钢相比，冷弯型钢薄壁型构件更容易制造，具有高强度重量比，易于运输和安装1。冷弯薄壁型钢结构住宅基本构件主要是 U型、C型以及L型截面3种截面形式，C型常用做梁柱承重构件2。单肢C型和U型钢截面构件加工简单，构件自重轻，装配速度快，但是单肢C型截面构件承载力较小，截面的形心与剪心不重合，因此容易发生扭转失稳。在实际工程中，对一些受力复杂的构件承载力要求较高，薄壁单肢截面承载力通常是不够的3。随着对冷弯薄壁梁柱构件承载力要求的提高，人们研究了多种拼合截面形式的冷弯薄壁构件。郭建勋等4研究了双U拼合以及腹板弯折的双 C 拼合的 I 型截面梁，对试件在ITF荷载条件下进行腹板压屈试验。研究发现试件均发生了受压腹板平面外屈曲破坏，腹板弯折的双C拼合试件还出现了整体屈曲，双C拼合试件的腹板屈曲承载力比双 U 拼合 I 型梁更大。MEZA等5对12个2种拼合形式的梁进行了四分点静载试验，一种是双U型钢工字形截面，另一种是在前者基础上加一个U形上导梁，试件均使用M6螺栓拼合组成，试验发现试件的破坏多为跨中腹板及上翼缘的局部屈曲，螺栓间距对构件承载力有影响。LAM等6进行了 4种截面形式梁的纯弯性能试验，分别是单肢C型、双肢抱合箱型(R型)、卷边I型和四肢抱合双腔箱型(2R型)。观察发现，C形和唇形I型截面梁的破坏形式主要是侧向扭转屈曲，而畸变屈曲是R型和2R型梁的主要破坏模式。ZHOU等7通过试验结合有限元的方法研究了 CU双肢抱合箱型截面柱的轴压性能，研究发现该类型柱在轴向压缩条件下发生了明显的局部屈曲变形，最后提出了一种预测组合箱形截面柱极限强度的简化设计方法。杜兆宇等8研究了由自攻螺钉1446第 4 期温会平，等：冷弯薄壁型钢四肢拼合梁柱节点抗弯性能研究将2个C型钢和2个U型钢拼合成箱型截面的拼合柱，进行了12根拼合箱型柱的轴压试验，试验试件在柱中部附近发生了局部破坏，通过试验数据结合数值模拟的方法对构件长度进行了参