梁柱“上焊下栓”节点受力性能

Mechanical Performance of Beam-column Connection with Upper Flange Welded-lower Flange Bolted

为研究"上焊下栓"节点梁塑性铰与拼接区滑移出现的先后顺序及拼接区耗能所占的比例,通过改变翼缘拼接板的截面面积,设计了2组试件,利用有限元软件ABAQUS对其进行了单调荷载和低周往复荷载作用下的有限元分析;同时以梁柱"上焊下栓"节点的BASE试件为例,对比分析了梁柱"上焊下栓"节点BASE试件与相同参数的"互"字形节点和传统栓焊混合节点的破坏模式、滞回曲线以及骨架曲线。结果表明:当翼缘拼接板为翼缘截面面积的2/3倍~1.0倍时,拼接区的板件变形和滑移能得到充分发展;当翼缘拼接板为翼缘截面面积的1.0倍~4/3倍时,梁拼接区的板件变形和滑移未能得到充分发展;在低周往复荷载作用下,2组"上焊下栓"节点的破坏模式相似,当梁端位移角约为0.024 rad时,梁下翼缘与拼接板开始出现滑移;当梁端位移角约为0.036 rad时,塑性铰出现在悬臂梁上;在整个加载过程中,梁拼接区的板件变形和滑移的耗能占总耗能的39%~45%;梁柱"上焊下栓"节点BASE试件的延性、耗能性能以及变形能力低于相同参数的"互"字形节点,但略高于传统栓焊混合节点。

In order to study the appearance sequence of plastic hinge and splicing slippages, and the proportion of energy dissipation of splicing, two groups of test specimens were designed by changing the cross-section area of flange splice plate. The finite element analysis of the new connection under monotonic and low cycle reversed loading was simulated by the ABAQUS software. Taking the BASE specimen of beam-column connection with upper flange welded-lower flange bolted as an example, the failure modes, hysteresis curves and skeleton curves of the BASE specimen of beam-column connection with upper flange welded-lower flange bolted were compared with those of the "HU" connection and the traditional bolted-welded hybrid connection designed with the same parameters. The results show that the deformation and the slipping of splicing can be fully developed when the cross-section area of flange splice plate is 2/3-1.0 times as large as the flange. The deformation and slipping of splicing cannot be fully developed when the cross-section area of splice plate is 1.0-4/3 times as large as the flange. Under low cycle reversed loading, the failure modes of the two groups of connections with upper flange welded-lower flange bolted are similar. When the interstory drift angle of beam end is about 0.024 rad, the lower flange and the splice plate begin to slip. When the interstory drift angle of beam end is about 0.036 rad, the plastic hinge appears on the cantilever beam. During the whole loading process, the energy dissipation of the deformation and the slipping of splicing account for 39%-45% of the total energy dissipation. The ductility, energy dissipation and deformation of BASE specimen of beam-column connection with upper flange welded-lower flange bolted are lower than those of the "HU" connection designed with the same parameters, but are slightly higher than those of the traditional bolted-welded hybrid connection.