型钢混凝土异形柱框架节点承载力试验研究

Experimental study of the bearing capacity of steel reinforced concrete specially-shaped column-beam joint

为研究型钢混凝土异形柱框架节点的破坏形态和承载力,采用柱端加载的方式对9个中间层边节点、4个角节点和4个中节点进行低周反复荷载试验。观察各类型节点的受力过程和破坏形态,分析节点区水平箍筋、水平腹杆和型钢腹板的应变分布规律以及节点的受力机理。结果表明,型钢混凝土异形柱框架节点典型的破坏形态为节点区剪切斜压破坏,其受力机理为斜压杆、刚框架-钢板剪力墙和约束机理的综合作用。通过对试验数据的回归分析,得到节点在弯剪作用下的受剪承载力以及在剪扭作用下受剪及受扭承载力计算公式,计算值与试验值吻合较好。最后给出节点的设计建议。

Seventeen specimens were tested under low cyclic reversed loading to investigate the bearing capacity and failure modes of steel reinforced concrete（SRC） specially-shaped column-beam joint.The failure process and patterns were obtained.Distributions of strains in the stirrups,web members and shape steel web and the shear mechanism of the joint are analyzed.The results indicate that the typical failure mode is shear diagonal compression in the core of the joint.The shear mechanism is the combination of strut-tie mechanism,rigid frame-steel shear wall mechanism and restriction mechanism.Through regression analysis of the test data,formulas for shear capacity under bend-shear action,shear and torsion capacity of the joint under shear-torsion action were put forward.The calculation results agree well with the test results.Suggestions for improving the design of such joint are also presented.