矩形钢管混凝土异形柱-钢梁框架节点抗震性能试验研究

为研究矩形钢管混凝土异形柱-钢梁框架节点的破坏特征和抗震性能, 进行了5个中节点、2个边节点和2个角节点的低周反复加载试验。观察了节点的受力过程及破坏形态, 分析了试件的荷载-位移滞回曲线、承载能力、强度和刚度退化、层间位移角和延性以及耗能能力等力学特性。结果表明: 矩形钢管混凝土异形柱-钢梁框架节点的典型破坏形态是节点域腹板的剪切破坏、节点核心区腹板与柱翼缘连接的竖向焊缝断裂; 试件滞回曲线饱满，层间位移延性系数介于1.44~2.74，弹塑性极限层间位移角约为1/43~1/21；等效黏滞阻尼系数介于0.227~0.316，表明节点域的变形和耗能能力较强。当柱截面肢高肢厚比为3、4时，破坏时节点核心区的剪切角约为0.01~0.03；当柱截面肢高肢厚比为2时，破坏时节点核心区的剪切角约为0.08~0.10。

Experimental study on seismic performance of joints between concrete-filled square steel tubular special-shaped columns and steel beams

In order to investigate the failure modes and seismic behavior of the joints between concrete-filled square steel tubular special-shaped columns and steel beams, 9 specimens were tested under reversed cyclic loading. The failure process and patterns were obtained. The failure characteristics, mechanical behavior such as the load-displacement hysteretic loops, load carrying capacity, degradation of strength and rigidity, inter-story drift, ductility and energy dissipation of the joints were analyzed. It is shown that the main failure patterns are shear failure of web in joint zone, vertical weld fracture between the web of the joint and the flange of the column. The hysteretic loops of the joints are in plump-shape. The story displacement ductility factors are between 1.44 and 2.74. The ultimate elasto-plastic inter-story drift is about 1/43 to 1/21. The equivalent viscous damping coefficient is about 0.227 to 0.316, indicating that the joint has good energy dissipation capacity. When the ratio of height to thickness of column section is 3 and 4, the shear deformation of joint core is about 0.01 to 0.03 at joint failure. When the ratio of height to thickness of column section is 2, the shear deformation of joint core is about 0.08 to 0.10 at joint failure.