方钢管混凝土柱-钢梁外加强环节点滞回性能的实验研究

Experimental studies on hysteretic behaviors of steel beam to concrete filled SHS column connections with stiffening ring

进行了8个方钢管混凝土柱-钢梁外加强环式节点试件在恒定轴力和水平往复荷载作用下的滞回性能实验研究,考察了钢管混凝土柱轴压比和环板宽度对节点力学性能的影响。结果表明:柱轴压比对节点的水平承载力和抗震性能影响较大,随着轴压比的增大,节点的水平极限承载力下降,位移延性和耗能能力降低;不同环板宽度节点的滞回曲线均为饱满的梭形,强度和刚度退化不明显;本次试验的8个节点试件的层间位移延性系数μ=3.00～7.41,弹性极限位移角θy≈2.03[θe]～5.30[θe],弹塑性极限位移角θu≈1.78[θp]～3.90[θp],等效黏滞阻尼系数he=0.3576～0.5339,均满足抗震设计要求。

Eight specimens of steel beam to concrete filled SHS （Square Hollow Section） column connections stiffened by outside rings were experimentally studied on the hysteretic behavior under combined constant axial load and cyclically lateral load. The axial load level of the concrete filled SHS columns and the width of the joint stiffening tings are considered as the experimental parameters of their seismic behavior. The results show that the axial load level of the column has an obvious effect on both the strength and seismic behavior of the connections. With the increase in axial load on the columns, the lateral ultimate strength of the connections become lower, and the ductility in displacement and the capacity of energy dissipation also decrease. The lateral load （P） versus lateral displacement （△） hysteretic curves of all the specimens with different width of outside stiffening tings are of a plump shuttle shape. The curves show no obvious strength deterioration and stiffness degradation. The story drift ductility index μ fluctuates between 3.00 and 7.41, the elastic limit of story drift angle θy between 2.03 [θe] and 5.30 [θe], the elastic-plastic limit of story drift angle θu between 1.78 [θp] and 3.90 [θp], and the equivalent damper coefficient he between 0.3576 and 0.5339. It can be concluded that the tested connections in the study demonstrate good seismic performance.