方钢管混凝土柱-钢梁栓焊混合节点抗震性能试验研究

Experimental Research on Seismic Performances of Bolt-Welded Hybrid Joints for Concrete-Filled Square Steel Tube Columns with Steel Beams

钢管混凝土柱-钢梁节点符合装配式结构发展需求,在工程中得到广泛应用。而以往震害发现,钢梁与柱壁焊缝在地震中易断裂而导致结构破坏。因此,将外肋环板与隔板贯通节点相结合,提出一种上环下贯式方钢管混凝土柱-钢梁栓焊混合节点。设计5个不同连接方式、柱形式和竖向肋板尺寸的方钢管混凝土柱-钢梁节点构件,通过低周往复荷载试验分析节点的破坏模式、滞回性能、延性和耗能能力。研究结果表明:所提出的新型方钢管混凝土柱-钢梁栓焊混合节点具有良好的抗震性能,等效黏滞阻尼系数比全螺栓节点高30%以上,满足强柱弱梁设计准则。上环下贯式比环板式节点具有良好的延性性能,方钢管混凝土柱能有效提高节点的承载能力和刚度,改变竖向肋板厚度和采用全螺栓连接形式对节点破坏模式影响显著。

The joints of concrete-filled steel tube columns with steel beams have been widely used in engineering,which meet the development requirements of prefabricated structures.However,it has been found that welding seams between steel beams and column walls were easy to fracture in earthquakes resulting in structural damage.Therefore,combined outer rib ring plates with the through-diaphragm connections,a new kind of bolt-welding hybrid joints for connecting concrete-filled square steel tube columns and steel beams,with upper ring plates and lower through-diaphragms was proposed.The failure modes,hysteretic performances,ductility and energy dissipation capacity of the five joint specimens with different connection types,column forms and vertical rib sizes were analyzed through quasi-static loading tests.The results showed that the proposed new joints had good seismic performances and could meet the design criteria requirement of“strong columns and weak beams”.The equivalent viscous damping coefficient of the joints was more than 30%higher than that of full-bolted joints.Compared with the ring plate joints,the upper ring plate and lower through-diaphragm joints had better ductility,and the concrete-filled steel tube columns could effectively improve the bearing capacity and stiffness of the joints.Changing the thickness of the vertical rib plate and using full-bolted connections had a significant influence on the failure mode of the joints.