预应力钢框架梁柱节点抗震性能研究

Study of the seismic performance of beam-column joint of prestressed steel frame

为减少钢框架结构在地震作用下的残余变形和损伤,提出一种新型预应力钢框架梁柱节点。梁柱通过预应力钢绞线进行拼接,当拼接处弯矩超过节点的临界张开弯矩时,梁柱节点张开;卸载后节点在预应力作用下重新闭合,实现自复位功能。采用理论与试验相结合的方法,先研究了预应力钢框架梁柱节点的基本构造和工作机理,推导出梁端剪力、轴力以及弯矩表达式,建立起节点弯矩-转角关系理论分析模型。然后对3个试件进行低周往复加载试验,分析预应力和抗滑移系数对节点抗震性能的影响。试验结果表明,施加预应力能明显提高节点的抗弯能力并减小其残余变形,使试件具有一定的自复位能力;预应力节点耗能系数β_E满足大于0.25的基本要求;基于试验结果,利用ABAQUS软件对试件进行非线性有限元分析,二者吻合较好。

In order to reduce the residual deformation and damage of steel frame structure under earthquake, a new type of prestressed steel frame beam-column joint is proposed. The beam-column joint is spliced by prestressed steel strands, and when the bending moment exceeds the critical opening moment of the joint, the beam-column joints are opened;after unloading, the joint is re-closed under the action of prestress to achieve self-reset function. By combining theory with experiment, the basic structure and working mechanism of beam-column joint of prestressed steel frame were studied, and the expressions of beam end shear force, axial force and bending moment were derived, and the theoretical analysis model of the relationship between moment and angle of joint is established. Then three specimens were subjected to low-cycle reciprocating loading test to analyze the influence of prestress and slip resistance coefficient on the seismic behavior of joint. Experimental results show that the application of prestress can obviously improve the bending resistance and reduce the residual deformation of the joints, so that the specimen has a certain self-reset ability, the energy consumption coefficient of the prestressed joint can meet the basic requirements of more than 0. 25. Based on experimental results, by using ABAQUS software, nonlinear finite element analysis of the specimen was carried out, and both results match well.