圆钢管混凝土K形相贯节点承载力计算模型研究

A Study on the Bearing Capacity Calculation Model of Concrete-Filled Circular Steel Tubular K-joints

以圆钢管混凝土平面K形相贯节点试验数据为基础,以弦杆径厚比γ、腹杆与弦杆管径比β、壁厚比τ和夹角θ为研究参数,建立有限元参数分析模型,进行非线性有限元参数分析,得到该类型节点的典型破坏模式,并建立了节点的极限承载力计算模型。结果表明:圆钢管混凝土K形相贯节点典型破坏模式是腹杆失效和弦杆冲剪破坏,控制指标是腹杆与弦杆的壁厚比τ和夹角θ。在CIDECT建议的空心圆钢管相贯节点基于冲剪破坏的极限承载力计算公式基础上,采用最小二乘法得到圆钢管混凝土K形相贯节点的冲剪承载力计算模型,并通过回归校验得出建立的公式具有较高精度。

Based on the test data of planar concrete-filled circular steel tubular K-joints,the diameter-thickness ratioγof the chord member,the diameter ratioβ,the thickness ratioτand the angleθbetween the web members and the chord member are the study parameters,finite element models are built,nonlinear finite element analyses are carried out to obtain the typical failure modes of this kind of joint and the ultimate bearing capacity calculation models are studied.The results show that the typical failure modes for the concrete-filled circular steel tubular K-joints include the buckling and yielding failure of the web members,and the punching shear failure for the chord member,while the control failure modes mainly depend on the thickness ratioτand the angleθbetween web members and chord member.Based on the ultimate bearing capacity formula for punching shear failure of a hollow circular steel tubular joints proposed by CIDECT,the capacity calculation model of the concrete-filled circular steel tubular K-joints is obtained by least square method.It is shown that the formula established in this paper has a good accuracy by regression calibration.