矩形钢管柱与H型钢梁单边螺栓连接节点的抗震性能与恢复力模型研究

为研究矩形钢管柱与H型钢梁单边螺栓连接节点抗震性能,对5个单边高强螺栓连接节点试件和1个常规高强螺栓连接节点试件进行了拟静力试验,研究了矩形钢管柱与H型钢梁单边螺栓连接节点破坏模式、滞回曲线、骨架曲线、延性、耗能、刚度退化等抗震性能指标,对比了单边高强螺栓与常规高强螺栓连接节点抗震性能的差异性;分析了节点构造参数对单边高强螺栓连接节点抗震性能的影响,根据节点滞回特性和单边高强螺栓受力特点提出了节点恢复力模型。研究结果表明:节点试件的破坏模式中单边高强螺栓均产生滑移现象;节点试件的滞回曲线捏缩严重,滞回曲线呈反S形,且有明显滑移直线段;节点试件初始转动刚度约为常规高强螺栓连接节点的70%,单边高强螺栓滑移使节点具有很大的转动变形能力,节点试件的极限转角为0.06~0.08 rad;节点的受弯承载力与常规高强螺栓连接节点基本一致,单边高强螺栓能够满足节点承载力设计要求;节点试件的等效黏滞阻尼系数为0.15~0.17,等效耗能系数为1.29~1.77,延性系数为1.62~2.26,其耗能和延性性能均低于常规高强螺栓连接节点;通过设置端板加劲肋可有效提高节点试件的抗震性能,设置内隔板对节点试件的抗震性能提高效果不明显;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。

Seismic behavior and restoring force model of connectionsbetween rectangular tubular columns and H-shapedbeams using single direction bolts

In order to study the seismic behavior of connections between rectangular tubular columns and H-shaped beams using single direction bolts, the pseudo-static tests of five connections using single direction high strength bolts and one connection using normal high strength bolts were carried out. The failure modes, hysteretic curves, skeleton curves, ductility, energy dissipation and stiffness degradation of connections between rectangular tubular columns and H shaped beams using single direction bolts were studied. The differences in seismic behavior of connections using single direction high strength bolts and normal high strength bolts were compared. The influence of structural parameters on the seismic behavior of connections using single direction high strength bolts was analyzed. According to the hysteretic characteristics of the connections and the stress characteristics of the single direction high strength bolts, the restoring force model of connections was put forward. The results show that the phenomenon of slip is produced by the single direction high strength bolts in all the failure modes of the connections. The hysteresis curves of the connections are pinching seriously, the shape of the hysteresis curves is reversed ‘S’ shape and the hysteresis curves produce obvious slip straight line. The initial rotational stiffness of the connection is about 70% of that of the connection using normal high strength bolts. The slip of the single direction high strength bolts makes the connections have a great rotational deformation capacity, and the limit rotation angle of the connections is 0.06~0.08 rad.The bending capacity of the connections is basically the same as that of the normal high strength bolts, and the single direction high strength bolts can meet the design requirements of the connections.The equivalent viscous damping coefficient of the connections is 0.15~0.17, and the equivalent energy dissipation coefficient is 1.29~1.77, and the ductility coefficient is 1.62~2.26, and their energy dissipation capacity and ductility performance are both not as good as that of the connection with normal high strength bolts. Setting the stiffener of endplate can effectively improve the seismic behavior of the connections, and the effect of setting up inner diaphragm on the seismic behavior of the connections is not obvious. The calculation curve of the restoring force model is in good agreement with the experimental curve.