（1 华东建筑设计研究总院， 上海 200002； 2 上海超高层建筑设计工程技术研究中心， 上海 200002）

［摘要］狗骨式节点能通过将塑性铰外移有效解决梁端脆性断裂破坏的问题从而保护梁柱节点区。从控制方程、设计准则、参数取值及构件验算等方面系统梳理了中美规范对于狗骨式节点的设计规定。基于假定的临界设计状态对上述规范之间的差异进行了详细的对比分析。研究结果表明：按照美国钢结构规范设计的狗骨式节点，塑性铰会优先或仅出现在削弱中心截面处，可实现塑性铰外移并保护梁柱节点区；而中国规范中的“强节点”公式中，计算节点区的承载力时使用了材料的极限强度，使得满足规范要求的截面削弱系数较小，难以保证节点区的塑性铰外移，且是否考虑钢梁腹板的抗弯作用对节点设计的影响有限。推导了弯矩梯度折减系数及框架梁抗侧刚度折减系数的计算公式，进一步明确了狗骨式节点在多遇地震设计组合下的强度复核原则和弹性分析时框架梁抗侧刚度的取值原则。最后给出了针对狗骨式节点的设计建议。

［关键词］狗骨式节点；塑性铰外移；临界设计状态；截面削弱系数；弯矩梯度折减系数；框架梁抗侧刚度折减系数

中图分类号：TU391文献标识码：A文章编号：1002-848X(2021)07-0059-07

Study on design method of reduced beam section  of rigid joint beam-to-column connection

HUANG Yongqiang1,2, YANG Chengdong1

(1 East China Architectural Design & Research Institute, Shanghai 200002, China; 2 Shanghai Engineering Technology Research Center of Super High Rise Building Design, Shanghai 200002, China)

Abstract:The reduced beam section (RBS) connection can effectively solve the problem of brittle fracture of the beam end by moving the plastic hinge away from column face, thereby protecting the beam-column connection area. From the aspects of control equations, design principle, parameter values and component checking calculations, the design requirements of the Chinese and American code for RBS connections were systematically combed. Based on the assumed critical design conditions, a detailed comparative analysis of the differences between the above specifications was carried out. The results of the study show that: for RBS connections designed in accordance with the American steel structure code, plastic hinges will be preferentially or only appearing at the weakened central section, allowing the plastic hinges to move away from column face and protect the beam-column connection; in the strong connection formula in the Chinese code, the ultimate strength of the material is used when calculating the bearing capacity of the connection area, so that the section reduction coefficient that meets the requirements of the code is small, and it is difficult to ensure the plastic hinge move away from column face. And whether to consider the flexural effect of the steel beam web has limited influence on the connection design. The calculation formulas for the bending moment reduction coefficient and the lateral stiffness reduction coefficient of frame beams were derived, the principle of strength review of RBS connections under the design combination of frequent earthquakes and the selection of frame beam lateral stiffness in elastic analysis were further clarified. Finally, design suggestions for RBS connections were given.

Keywords:reduced beam section connection;plastic hinge away from column face;critical design condition;section reduction coefficient;bending moment reduction coefficient;reduction coefficient for frame beam lateral stiffness

作者简介：黄永强，硕士，高级工程师，Email:hyq@ecadi.com；通信作者：杨成栋，硕士，助理工程师，Email:ycd24813@ecadi.com。