【摘要】 框架顶层角节点在低周反复荷载作用下梁柱交角将增大或减小。通过6个钢筋混凝土框架顶层角节点在低周反复荷载作用下的受力性能试验,分析了梁上层筋在节点内弯曲锚固长度、节点配箍量、柱筋端部锚固形式及节点内角斜拉筋量等试验参数对角节点的破坏类型、变形特征及强度等抗震性能的影响。试验结果表明:与框架中间层中节点及中间层边节点不同,框架最上层角节点的受力变形不但有剪切变形而且包含弯曲变形成分;梁柱交角增大或减小时,角节点受弯破坏特性表现迥异且节点强度有很大差异;在梁筋锚固充分的前提下,梁柱交角减小时的节点破坏为弯剪破坏,节点强度由柱筋锚固形式、节点配箍量等参数决定;梁柱交角增大时,节点破坏表现为弯曲破坏特征,节点强度受节点箍筋量、节点内角斜拉筋量的影响很大。文中还对中日两国规范节点强度设计值与试验值进行了比较。更多还原

【Abstract】 Reinforced concrete frames under reverse loading may lead to angle variations between beams and columns,especially for the Knee-joints at the top level of the frames.Experiments were carried out for six reinforced concrete Knee-joints subjected to cyclic loading.The effects of the anchorage length of the top bars in the beam bended into the joint,the amount of joint hoops,the anchorage methods of column bars and the amount of diagonal reinforcement in the joint on seismic behavior of Knee-joints were discussed,including failure modes,deformation features and joint strength.The experimental results show that compared with interior joints or Tee-joints,Knee-joints experience both shear deformation and flexural deformation.When the angle between the beam and the column framing into the joint varies inversely,significant differences in failure mechanisms and failure strength of the joint are observed.In the case of beam bars with adequate anchorage length,the joint shows flexural-shear failure pattern when the angle between the beam and column framing into the joint decreases and the failure strength is governed by the anchorage column bars,the amount of the joint hoops.When the angle between the beam and column increases,it shows flexural failure pattern and the failure strength is influenced mainly by the amount of joint hoops and the amount of the diagonal tensile bars.The comparison between the test results and the calculated values of the joint strength based on the Chinese code and the Japanese code was also carried out.更多还原