装配式混凝土框架混合连接中节点抗震性能模拟

Numerical simulation on seismic performance of hybrid-connection joints in prefabricated concrete frame structures

基于框架结构“强节点弱构件”的抗震需求和节点易于实现可靠连接,提出一种新型钢筋混凝土框架装配式混合连接节点形式。考虑梁端刚/柔性两种连接方式,采用有限元软件ABAQUS建立2个新型钢筋混凝土框架装配式混合连接中节点模型和1个现浇对比试件模型,并对其进行水平循环往复荷载下的抗震性能模拟。根据模拟数据整理,对试件滞回性能、节点转动刚度、耗能能力和破坏模式进行对比分析。研究结果表明:装配式混合连接节点采取钢管混凝土实现了节点区混凝土斜压带和钢板斜拉带协同抗剪机理,提高了节点核心区抗剪能力,更好地满足“强节点”的抗震需求;装配式连接节点梁端刚/柔性连接方式均不同程度实现了梁端塑性铰区远离节点区;梁端刚性连接装配式连接节点试件的塑性铰区距离节点区最远,其整体性最好,初始抗弯刚度最大;梁端柔性连接装配式连接节点试件的塑性铰区范围较大,损伤耗能发展持续,而梁端刚性连接试件的塑性铰区相对集中,损伤耗能发展快速充分。

To meet the seismic requirements of“strong joint and weak member”of frame structures,facilitate convenient construction,and achieve the reliability of joints,this paper proposes a novel beam-column joint of prefabricated concrete frames.Considering the rigid/flexible connection mode at the beam end,two specimens of interior joints of prefabricated reinforcement concrete frames and a cast-in-place specimen for comparison were designed using the finite element software ABAQUS.The seismic performance of these specimens under lateral cyclic loading was simulated.Their hysteretic behavior,rotational stiffness,energy-dissipation capacity,and failure mode were compared and studied.The results show that the concrete-filled steel tube adopted in the prefabricated beam-column joint realizes the cooperative shear mechanism of the concrete compression field and the steel tension field in the panel zone,improves its shear capacity,and meets the seismic requirement of“strong joint.”The prefabricated beam-column joints with rigid/flexible connection mode at the beam ends keep the plastic hinge zone of the beam end away from the connection area.The prefabricated beam-column joint with a rigid connection at the beam end has the largest initial bending stiffness and the best integrity.The plastic hinge zone of the specimen with a flexible connection at the beam end is large,and its damage energy-dissipation process is sustainable,whereas the plastic hinge zone of the specimen with a rigid connection is concentrated,and its damage energy dissipation is developed rapidly.