PEC柱-异形钢梁框架中节点抗震性能试验研究  

EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF PEC COLUMN-SPECIAL SHAPED STEEL BEAM INNER-FRAME JOINTS

作　　者：李补拴 路瑶 赵根田 闻洋 LI Bu-shuan;LU Yao;ZHAO Gen-tian;WEN Yang(School of Civil Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学土木工程学院

出　　处：《工程力学》2020年第1期126-134,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(51268042,51768056);内蒙古科技大学土木工程学院攀登计划项目(KY-01)

摘　　要：为研究 PEC 柱(partially encased concrete composite column)-型钢梁框架中节点破坏特征及抗震性能,完成了 3 个 PEC 柱-型钢梁中节点及 1 个钢框架梁柱中节点对比试件的低周往复加载试验。分析了试件中节点的破坏形态、滞回耗能、承载能力、延性性能、强度退化、刚度退化、节点域力学机理,研究了轴压比及梁截面变化对该类中节点抗震性能的影响。研究结果表明:PEC 柱-型钢梁中节点滞回曲线呈纺锤形,具有钢框架节点的力学特性;型钢柱内部填充混凝土后试件初始刚度、承载力分别提升约 40%、31.1%,且试件仍具有较好的延性性能及耗能能力;当轴压比试验值为 0.25~0.35 时,随着轴压比增加,试件承载力显著增加,延性性能有所下降,耗能能力则有所提升;试件均为梁弯曲破坏,损伤程度无明显变化。改变柱一侧梁的截面尺寸后,试件的承载能力、延性性能有一定提升,耗能能力、强度及刚度退化规律无明显影响,但 PEC 柱-变截面型钢梁中节点发生节点核心区剪切破坏,主要原因为改变柱一侧梁截面高度后,造成节点域输入剪力增大所致。按常规节点设计的变截面梁中节点不能满足“强节点弱构件”的抗震设计要求,在进行工程设计时应予以重视。To study the failure pattern and seismic performance of PEC column(partially encased concrete composite column)-steel beam inner-frame joints,three PEC column-steel beam inner-frame joints and one steel frame beam-to-column inner-frame joint were tested under low-cycle reversed loading.Several parameters including the failure mode,hysteretic behavior,load carrying capacity,ductility performance,degradation of strength and stiffness and mechanical mechanism of the inner joints were analyzed.The effect of axial load ratio and beam section variation on the seismic performance of the joints were studied.Experimental results indicated that the hysteresis curve of PEC column-steel beam inner-frame joints was of a spindle shape,and these joints had similar mechanical characteristics to steel frame joints.The initial stiffness and capacity increased about 40%and 31.1%respectively,while steel column filled with concrete.The specimens still had good ductility performance and energy dissipation ability.As the test axial load ratio increased from 0.25 to 0.35,the bearing capacity and the energy dissipation capacity of the specimens increased while the ductility performance decreased.The failure feature of specimens are the bending of beams and no obvious change in the degree of damage.The capacity and ductility performance of specimens were improved when the beam section on one side of the column were changed.The energy dissipation capacity,strength and stiffness degradation have no noticeable changes due to the variation in the beam section, but the failure patterns of the inner-frame joints were shearing diagonal compressionin joint zones. The main reason for the failure patterns was the increase in the input shear force in the joint withthe variation of the beam height on one side of column. The variable section beam joints designed according to theconventional joints cannot meet the seismic design requirements of the "strong node weak member", and itshould be taken into serious account in engineering design.

关 键 词：PEC柱-型钢梁 低周往复加载试验 轴压比 梁截面变化 抗震性能 

分 类 号：TU398[建筑科学—结构工程]