型钢混凝土L形柱-混凝土梁框架节点滞回性能试验研究

为研究型钢混凝土L形柱-混凝土梁框架节点的滞回性能，以柱截面配钢形式、轴压比、水平加载角度及 有无楼板参与工作为变化参数，进行4个平面和7个空间L形柱-混凝土梁框架节点的拟静力试验；比较分析试件的 破坏形态、滞回曲线、承载能力、刚度退化、耗能能力、位移延性以及层间位移角等抗震性能指标。研究结果表 明：平面节点和空间节点的破坏形态分别为核心区发生剪切破坏和梁端出现塑性铰，带楼板工作的钢筋混凝土梁 柱空间节点出现板的弯曲破坏以及梁底出现塑性铰的破坏模式；配实腹式型钢试件的滞回曲线比配空腹式型钢试 件的饱满；平面节点的承载能力比空间节点的大，但耗能能力、位移延性及抗倒塌能力均不及空间节点；楼板的 存在对节点承载能力的提高和维持刚度的稳定均具有有利作用；轴压比可提高节点的承载力和初始刚度；L形柱 框架节点的层间变形能力大于规范规定的层间位移角限值。通过引入加载角度，提出了型钢混凝土L形柱-梁空间 节点受剪承载力计算模型，其能较好地反映节点核心发生剪切破坏的传力机制。

Experimental study on hysteretic behavior of L-shaped SRC column-concrete beam joints

To study the hysteretic behavior of L-shaped steel reinforced concrete (SRC) column- concrete beam joints, four planar joint specimens and seven 3D joint specimens were tested under the quasi-static state, and the varying parameters included steel form for cross section of column, axial compression ratio, horizontal loading angle and participation of floor slab. The failure mode, hysteresis curve, bearing capacity, stiffness degradation, energy dissipation capacity, displacement ductility and storey drift angle were compared and  analyzed for those specimens. The test results show that for planar joints, the main failure mode is the shear failure, while for 3D joints, their failures are attributed to the plastic hinge appeared in the beam end. For RC 3D joints with floor slab participated, the main failure modes  shall be the flexural failure of floor slab and the plastic hinge appeared at the bottom of beam. The hysteresis curves of specimens with solid-web steel shall be more plump than those of specimens with hollow-web steel. The bearing capacity of planar joints is larger than that of 3D joints, but their energy dissipation capacity, displacement ductility and collapse resistance shall be inferior to those of 3D joints. The existence of floor slab shall be beneficial to the enhancement of bearing capacity and the stability of stiffness for the joints. A large axial compression ratio can increase the bearing capacity and the initial stiffness of specimens. The storey deformation capacity of L-shaped column frame joints is larger than the storey drift angle limit specified by code. By introducing the loading angle, the calculation model of shear capacity is proposed for L-shaped SRC column-beam 3D joints, and the model can reflect the forcing mechanism of shear failure in the core of joint.