腹板中心开长圆孔可更换剪切耗能梁段的承载力研究  

Study on bearing capacity of replaceable shear link with an elongated circular opening at web centerline

作　　者：冯大哲 殷占忠[1,2] 吴宏凯 任国超 FENG Dazhe;YIN Zhanzhong;WU Hongkai;REN Guochao(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of China Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050

出　　处：《建筑结构学报》2024年第10期193-205,共13页Journal of Building Structures

基　　金：甘肃省优秀博士生项目(22JR5RA234);国家自然科学基金项目(51968044)。

摘　　要：通过在腹板上开孔削弱耗能梁段截面的抗剪强度,可以达到在不改变梁段端部连接处截面大小的情况下调控梁段受剪承载力的目的。为此,对4个腹板中心开长圆孔的可更换剪切耗能梁段进行了循环加载试验及有限元分析,得到了梁段在剪切荷载作用下的应力分布、破坏模式、滞回性能以及承载力,探讨了水平加劲肋的布置对腹板开口角部局部屈曲的改善情况,研究了孔长变化对设置水平加劲肋的梁段的应力分布及破坏模式的影响,并基于破坏模式给出了该类构件的受剪承载力理论计算式。结果表明:梁段截面的极限塑性转角均超过了ANSI/AISC 341-16规定的塑性转角限值0.08 rad;无肋梁段最终在开口部位发生剪切屈曲破坏,体现为长圆孔边缘四个圆弧过渡区域形成屈曲拉力带;腹板水平加劲肋的布置可有效抑制长圆孔周边屈曲拉力带的形成,长圆孔宽度方向两侧的腹板均达到了钢材的抗拉强度,梁段的破坏模式表现为开口处的剪切和空腹破坏;设置水平加劲肋的腹板中心开长圆孔剪切耗能梁段比相同开口参数的无肋梁段具有更高的承载力和耗能能力,梁段的受剪承载力随孔长的增加而降低,实现了通过调整孔长控制梁段受剪承载力的目标。采用建议的受剪承载力计算式的计算结果与试验值比值的标准偏差为0.076,变异系数为0.075,可见,该计算式能够提供可靠的受剪承载力预测结果。The shear strength of the shear link is weakened by opening a hole in the web to accomplish the bearing capacity regulating without changing its cross-sectional size at the link ends.The cyclic loading tests and finite element analyses were conducted on four replaceable shear links featuring an elongated circular hole at the center of the web.The stress distribution,failure modes,hysteretic behavior,and bearing capacity of the links under shear force were obtained,as well as the role of horizontal stiffeners in reducing localized buckling at the corner of the web opening.Additionally,the effects of changes in hole length on the stress distribution and damage modes of horizontally stiffened links were investigated.The theoretical formulas for the shear capacity of such members were developed based on the observed damage modes.The results indicate that the inelastic rotation of the links all exceeds O.08 rad specified in the ANSI/AISC 341-16 provisions.Unstiffened links eventually experience shear buckling damage at the opening site,characterized by buckling tension bands forming in the four circular arc transitional regions at the edges of the elongated circular opening.Horizontal stiffeners in the web effectively prevent the formation of buckling tension bands around the periphery of the elongated circular opening.The webs on both sides of the width direction of the elongated circular opening reach the tensile strength of the steel,with the damage modes of the link involving shear and vierendeel damage at the perforation.Horizontally stiffened links exhibit higher bearing and energy dissipation capacities compared with unstiffened links with the same opening parameter.Additionally,the ultimate bearing capacity of the links decreases as the hole length increases,allowing for the control of shear capacity by adjusting the opening length.The standard deviation of the ratio between calculated and experimental values using the proposed formula for shear bearing capacity is 0.076,with variation coefficient of 0.075.It

关 键 词：腹板开长圆孔可更换剪切耗能梁段 循环加载试验 有限元分析 破坏模式 受剪承载力 

分 类 号：TU391[建筑科学—结构工程] TU317.1