【摘要】 本文首先回顾了国内外不同规范与研究中平面K形圆钢管搭接节点承载力公式及理论模型，阐述了现有计算公式存在的问题。之后通过有限元参数分析，研究了不同几何形状下节点的破坏模式及其分布规律，比较和分析了节点几何参数、支管搭接顺序和隐蔽部分焊接与否对节点承载力的影响，并基于此给出了节点构造的建议。根据节点效率的概念，通过将节点承载力除以支管截面屈服承载力对节点承载力进行无量纲化，构造出形式简洁、物理意义明确的公式形式，并采用回归分析确定了节点效率系数。通过将多组试验数据与有限元分析结果进行比较，验证了该公式具有较高的精度和可靠性，并且在支管不对称的情况下也具有良好的适用性。该承载力公式已被现行《钢结构设计标准》（GB 50017—2017）所采纳。更多还原

【Abstract】 This paper introduces the evolution of ultimate capacity equations for overlapped CHS K-joint and reveals the shortcomings of existing equations. A finite element parametric analysis was conducted to study the failure modes of overlapped joints with various geometric configuration. The effects of different parameters, including joint geometric dimension, brace overlapping sequence and the presence or absence of hidden weld, on ultimate capacity were compared and analyzed, based on which the detailing suggestions on joints were proposed. Through the joint efficiency concept, the joint capacity was nondimensionalized by dividing by the brace section yielding strength, resulting in a simplified and rational capacity formula. The joint efficiency factor was determined by multiple regression analysis. Compared with several sets of experimental and numerical results, the precision and reliability of the proposed formula were proved, and meanwhile the formula can be also applicable to unsymmetrical joints. The capacity equation has been adopted in current standards for design of steel structures.更多还原