T形钢管混凝土柱-工字钢梁框架顶层边节点抗震性能试验研究

选择T形截面钢管混凝土异形柱-工字钢梁框架顶层边节点为研究对象，按1∶2的缩尺比例设计并制作3个“弱节点”模型和1个“强节点”模型，通过施加恒定轴压比的竖向荷载和低周往复水平荷载，对节点模型进行加载破坏试验，观察节点模型的受力过程和破坏形态，得到水平荷载-柱端位移滞回曲线和骨架曲线，分析节点荷载特征值、延性、耗能以及刚度退化等。试验结果和分析表明：弱节点试件破坏形态主要为节点核心区在剪压复合应力作用下的剪切破坏，随轴压比增大，试件受剪承载力提高，但其延性和耗能能力有所下降；强节点试件破坏形态为钢梁的局部屈曲破坏，节点区基本完好，滞回曲线饱满，延性系数为3.89；合理地设计钢管混凝土异形柱-钢梁框架边节点，可满足抗震延性要求，实现“强柱弱梁，节点更强”的抗震设计目标。

Experimental research on seismic behavior of top corner joints in composite frame consisting of CFST T-shaped columns and steel beams

Taking the top corner joint in a composite frame consisting of concrete-filled steel tube(CFST) T-shaped columns and steel beams as the research object, one half scaled models of three weak joints and one strong joint were designed and manufactured, and the destruction tests on the models were carried out under constant vertical load and lateral cyclic load. The loading process and the failure modes were observed, and the horizontal load versus displacement hysteretic loops and skeleton curves were obtained. Based on the experimental results, the mechanical properties of the models such as the characteristic values of loads, ductility, energy dissipation, stiffness degradation were analyzed. The failure mode of the weak joints is the shear failure subjected to axial load, bending moment and shear force in the core area, and that of the strong joints is the local buckling of the beam. With the increase of axial compression ratio, the shear bearing capacity of the weak joints increases, however, the ductility and the energy dissipation capacity decrease. The core of the strong joint is undamged, and the hysteretic loops are plump. The effective ductility factor of the model is 3.89. The top corner joint in the composite frame consisting of CFST T-shaped columns and steel beams has the ductile failure mode by the rational design, and meets the strong column-weak beam-strong joints requirement of seismic design.