树状结构二分叉铸钢节点抗弯极限承载力的几何影响因素及计算方法研究

STUDY OF GEOMETRICAL FACTORS AND COMPUTING METHOD FOR THE ULTIMATE FLEXURAL CAPACITY OF CAST-STEEL JOINT WITH TWO BRANCHES IN TREE-LIKE STRUCTURE

用ANSYS有限元分析方法分析了树状结构二分叉铸钢节点在两类弯矩(节点核心区受压或受拉)分别作用下的几何因素对抗弯极限承载力的影响,并在此基础上拟合出该类节点抗弯极限承载力计算式。分析结果表明:在两类弯矩分别作用下,当节点几何尺寸相同时,节点抗弯极限承载力相差不大;主、分管之间夹角,主、分管之间倒角半径,分管之间外壁倒角半径,分管之间内壁倒角半径对节点抗弯极限承载力影响不大;主管径厚比对节点抗弯极限承载力影响较大;随分管与主管外径比增大,节点承载力近似线性增大;随分管与主管壁厚比的增大,节点抗弯极限承载力近似线性增大。

The effect of geometrical factors on the ultimate flexural capacity of the spatial cast-steel joint with two branches in the tree-like structure loaded respectively by two kinds of bending moment（ joint core area under tension or compression） has been intensively studied using the finite element method. The ultimate flexural capacity formula for caststeel joint with two branches in tree-like structures was derived based on the analysis. The results showed that the difference of the ultimate flexural capacity of joint loaded by two kinds of bending moment was small when the geometrical dimensions of joints were same; the effect of the inner angle between chord and branch,chamfering radium between chord and branch,inside and outside chamfering radium between branches on the ultimate flexural capacity of joint was small; the effect of the diameter to thickness ratio of chord on the ultimate flexural capacity of joint was large; the bearing capacity of joint increased approximately linearly with the increase of the branch diameter to the chord diameter ratio; the ultimate flexural capacity of joint increased approximately linearly with the increase of the branch thickness to the chord thickness ratio.