装配式梁柱外环板高强螺栓连接节点抗震性能试验研究

Experimental study on seismic behavior of prefabricated beam-to-column high-strength bolted joint with external diaphragms

针对装配式梁柱外环板高强螺栓连接节点抗震性能开展了拟静力加载试验,研究节点试件的破坏模式、滞回曲线、骨架曲线、延性、耗能、刚度退化等抗震性能指标;并对影响节点试件抗震性能参数进行分析;研究节点试件层间位移角及转动能力;提出节点恢复力计算模型。研究结果表明:节点试件失效模式为外环板与梁翼缘连接螺栓剪断、梁翼缘钢板断裂、外环板与柱连接处焊缝开裂3种形式;4个节点试件的滞回环面积较为饱满并呈"Z"形,具有较强的耗能能力;4个节点试件均有显著的刚度退化现象,下降坡度平缓;4个节点试件的层间位移角为0.09~0.12rad超过抗震规范的要求,表明节点具有良好的转动能力和延性性能;外环板的厚度和宽度对节点抗震性能有一定影响;提出的节点恢复力计算模型与节点试件的试验曲线吻合较好。

A quasi-static loading test on seismic behaviors of the prefabricated beam-to-column high-strength bolted joint with external diaphragms was conducted.The failure mode,hysteretic curve,skeleton curve,ductility,energy dissipation and stiffness degeneration were analyzed.The influences of structural parameters on seismic behavior of joint specimen were also discussed.The story drift and rotational capacity of joint specimen were analyzed.Consequently,a hysteretic model of the joint was proposed.Results indicate that three failure modes may develop in joint specimens,namely shearing failure of connecting bolt between external diaphragm and flange of bolt,tensile failure of flange of beam,and weld failure at connection between the external diaphragms and column.The hysteretic curves of joint specimens appear to be"Z-shape"with great area,implying their strong energy dissipation capacities.The 4 joint specimens suffer from significant stiffness degeneration with gentle descending gradient.The story drifts of 4 joint specimens varies in the range of 0.09~0.12 rad which exceed the requirements in seismic code,reflecting good rotational capability and ductility of the proposed joint.Seismic behaviors of the joint can be influenced to some extent by the thickness and width of external diaphragms.The resilience calculation model of the proposed joint agrees well with test curves of joint specimens.