改进扩大型焊接孔梁柱节点子结构动态抗倒塌性能研究  

Experimental and numerical study on dynamic collapse resistance of steel beam-column connections with enlarged weld access holes

作　　者：陈英[1] 霍静思[1,2] 王海涛[1] CHEN Ying;HUO Jingsi;WANG Haitao(Key Laboratory of Building Safety and Energy Efficiency of China Ministry of Education, Hunan University,Changsha410082,China;College of Civil Engineering,Huaqiao University,Xiamen 361021,China)

机构地区：[1]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082 [2]华侨大学土木工程学院,福建厦门361021

出　　处：《建筑结构学报》2019年第3期230-239,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51078139);教育部新世纪优秀人才计划项目(NCET-11-0123)

摘　　要：对试验中采用改进扩大型焊接孔的2个钢结构全焊接梁柱节点分别施加静力荷载和落锤冲击作用,以模拟得到子结构的静、动态倒塌响应,考察静态和动态两种不同加载方式对此类梁柱节点抗倒塌性能的影响。通过试验获得节点的破坏模式及其冲击作用和位移时程曲线等,分析冲击过程中静、动态响应规律以及节点转动能力。试验结果表明:改进扩大型焊接孔构造的节点,其主要破坏形态是钢梁上翼缘屈曲,下翼缘纵向塑性拉伸大变形以及沿焊接孔边缘的开裂等。另外,改进后的焊接孔构造对节点转动性能的影响显著; 2个节点均具有良好的转动性能,其最大转角远超过FEMA 351标准抗倒塌设计的转角限值(θ=0.064 rad)要求。对比以往研究成果,给出了冲击作用下刚性节点的归一化冲击能与转角拟合公式。采用ABAQUS软件建立了扩大型焊接孔构造节点的有限元分析模型,通过不同加载时刻子结构内力分布情况可知,冲击加载初期的局部响应对节点子结构的整体响应影响可忽略,表明采用落锤冲击加载方法研究结构抗倒塌具有可行性;通过分析节点在冲击作用下内力发展规律可知,改进扩大型焊接孔构造节点良好的转动性能有利于悬链线的形成。Two steel beam-column connections with improved enlarged weld access holes were designed and tested, and both static and dynamic collapse behavior of the fully welded connections were considered and investigated under static load and drop-hammer impact force. The fundamental behavior and rotational capacities of the connections under both static and dynamic loads were analyzed by examining the failure modes and time histories of the impact force and deformation of the specimens. The test results show that the failure modes of the steel beam-column connections mainly include buckling of the top flange of the beam, longitudinal plastic tensile deformation of the bottom flange, as well as crack along the edge of the weld access hole. Additionally, the details of the weld access hole have a significant effect on the rotational capacity of the connection. Both connections have good rotational capacity and their maximum rotations are much larger than the design limit of FEMA 351(θ=0.064 rad). A fitting formula describing the relationships between the normalized impact energy and connection rotation was proposed by summarizing the test results in previous and present studies. A finite element(FE) model of the steel beam-column connection with enlarged weld access holes was established using ABAQUS. The distributions of the internal forces of the connection at different impact loading stages show that the local response of the connection at the initial loading stage has no influence on the overall response at later stage, indicating the feasibility of using drop-hammer impact loading for studying the structural anti-collapse behavior. Furthermore, the development of the internal force of the connection under impact loading demonstrates that the good rotational capacity of the steel beam-column connection with improved enlarged weld access holes contributes to the formation of the catenary action.

关 键 词：梁柱节点子结构 扩大型焊接孔 冲击试验 悬链线效应 抗倒塌能力 

分 类 号：TU392.1[建筑科学—结构工程] TU317.1