钢管混凝土柱-混凝土梁外加强环搭接节点抗震性能试验研究及有限元分析

Experimental research and finite element analysis on seismic performance of lap connections between concrete-filled steel tube column-concrete beam with external ring

对东莞某37层商业中心的钢管混凝土柱-混凝土梁外加强环搭接节点进行了拟静力抗震性能试验研究,根据实际工程设计制作了4组8个1∶5的节点试验模型,采用219的Q345无缝钢管混凝土柱-混凝土梁节点。第1,2组试件为刚接节点,焊接在外加强环的外伸牛腿上,用以分析不同轴压比作用下节点的抗震性能;第3,4组试件为搭接节点,梁主筋搭接在外加强环的外伸牛腿上,牛腿长度不同,用以分析牛腿长度不同对节点抗震性能的影响。考虑地震的P-Δ效应,加载时采用柱端加载方式进行拟静力试验,得到了节点的滞回曲线及破坏情况,分析了其延性系数、等效粘滞系数、强度与刚度退化等抗震指标以及破坏机理,并利用ABAQUS软件对节点进行了周期加载模拟,计算所得骨架曲线与试验结果吻合良好,可为实际工程设计提供参考依据。

Based on a 37-floor business center in Dongguan, a quasi-static seismic performance experimental research was carried out on lap connections between concrete-filled steel tube column-concrete beam with external ring. Four groups of eight test models with 1 ： 5 scale ratio were made according to the actual engineering design and connections adopt seamless steel tube column （strength of Q345 and diameter of dp219） -concrete beam. Specimens of group 1 and 2 were welded on the overhanging corbel of external ring in the form of rigid connection to analyze seismic performance of the connection under different axial compression ratios. Specimens of group 3 and 4 were lapped on the overhanging corbel （different lengths） of external ring in the form of rigid connection to analyze seismic performance of the connection under different lengths of overhanging corbel. Considering seismic P-A effect, quasi-static test was carried out in the loading way at the end of the column. Hysteresis curve and the damage situation were obtained. The ductility factor, equivalent viscous coefficient, seismic indexes such as strength and stiffness degradation, and failure mechanism were analyzed. Cycle loading simulation was carried out on connections using ABAQUS finite element software to get skeleton curves that are in good agreement with test results, providing a reference basis for practical projects.