Influence of Aspect Ratio of Joint on Behavior of Interior R/C Beam-Column Joint

根据试验结果和基于有限元的三维非线性分析结果，讨论了节点高宽比对内部钢筋混凝土梁柱节点性能的影响。纵横比是梁深度除以柱深度的值。试验试件为节点破坏类型，节点长宽比取值在0.6~2.0之间。从试验结果和分析结果可以得出以下结论：1.对于高宽比较大的梁柱节点，不能用梁高与柱高相近的高宽比方法对节点的破坏模式进行分类；2.采用常规设计方法无法用经验公式估算高宽比较大的梁柱节点的抗剪强度。根据节点和柱的受力状态的相似性，可以用柱的极限抗剪强度经验公式计算节点的抗剪强度。3从节点压应力的检验可以预测，在节点极限抗剪强度时，压杆作用是主要的作用机制。4提出的柱和梁变形经验公式可以分别计算节点最大强度时的层位移和节点变形的实测值。5三维非线性分析结果表明，在相同的节点剪切水平下，大高径比试件的节点压应力和节点剪切变形较大。

The influence of aspect ratio of joint on behavior of interior R/C beam-column joint is discussed from the experimental results and the results of three-dimensional nonlinear analysis based on Finite Element Method. The aspect ratio is the value that divides beam depth by column depth. The test specimens are joint failure type with the value of aspect ratio of joint from 0.6 to 2.0. The following conclusions are obtained from the test results and the results of analysis:1 It is impossible to classify the failure modes of beam-column joints with large aspect ratio by means of proposed method for aspect ratio which beam depth is nearly equal to column depth.2 The joint shear strength of beam-column joint with large aspect ratio cannot be estimated by experimented formulas using conventional design practice. From the similarity between the stress state of joint and column, the joint shear strength can be calculated by experimental formula for ultimate shear strength of column.3 From the examination of compressive stress in joint strut, it can be predicted that strut action is main mechanism at the ultimate joint shear strength.4 Story displacement at maximum strength can be calculated by means of the proposed experimental formula for column and beam deformations, and the measured value for joint deformation, respectively.5 The results of three-dimensional nonlinear analysis indicate that the strut compressive stress in joint and the joint shear deformation for specimen with large aspect ratio is large at the same joint shear level.