平面K型圆管节点新的承载力计算公式

A New Formula for Loading Capacity of Unstiffened CHS K-joints

建立了平面K型节点非线性有限元分析模型,综合考虑两支管搭接顺序和内隐蔽部分焊缝是否焊接等影响因素,并得到了试验验证,适应性良好.应用该模型,对4类圆管K型节点型式进行了分析计算,通过多元非线性回归,导出K型节点极限承载力新的计算公式,进而提出承载力设计值建议公式.采用国际管节点数据库中试验数据,与现有国内外规范公式进行比较评价,证明该公式有较高的精度和广泛的适用性,能综合反映影响承载力的诸多因素,公式可同时计算间隙型和搭接K型节点,可计算两腹杆具有不同几何参数以及弦杆有轴力作用的K型节点承载力等特点.

A nonlinear finite element model simulating the behavior of unstiffened circular hollow section （CHS） K-joints was first developed and validated by experiments, in which two influencing factors were considered such as an overlap sequence between two braces and a hidden weld to be connected or not. Then, this model was used to analyze four types of CHS K-joints. By means of multiple nonlinear regression analysis techniques, a new formula for ultimate capacity of CHS K-joints was proposed and then a design formula was recommended. Finally, by using the experimental data of tubular joints from an international database, the proposed design formula was compared with some existing design formulae from codes in the world. It is concluded that the proposed formula shows better accuracy and wider application, including the consideration of all effectson loading capacity. It is suitable for both the gap and overlap K-joints, and also suitable for the K-joints with two different braces and subjected to an axial force in the chord.