树状结构三分叉铸钢节点有限元分析

Finite elment analysis of a cast-steel joint with three branches in tree-like structure

结合某实际结构工程,对三分叉铸钢节点进行有限元分析。首先设计并应用SOLIDWORKS建立考虑管径、壁厚、倒角半径、分叉角度等因素影响的计算模型,然后应用ANSYS计算轴力和弯矩共同作用下节点的应力状态,分析节点应力分布特征及最大应力出现的位置,并对影响节点受力性能及破坏模式的参数进行分析。研究结果表明:弯矩对节点最大应力的影响显著;三分叉铸钢节点主要存在主管轴向屈服、主分管交界处局部屈曲、分管撕裂破坏等3种破坏模式,节点受轴力作用且管壁相对较厚的情况下,发生主管轴向屈服破坏;节点受轴力作用、支管直径相对较大而管壁较薄的情况下,发生主分管交界处局部屈曲破坏;节点弯矩作用较大的情况下发生分管撕裂破坏。

Based on the practical project of a hotel,the cast-steel joint with three branches in the tree-like structure was studied using FEM. At first,the calculating models of the cast-steel joints with three branches considering the factors,such as tubular diameter,thickness of wall,chamfer radius and bifurcation angle were designed and constructed using SOLIDWORKS software. Then the stress distribution of joint under the combined action of the axial force and bending moment were calculated using ANSYS software. The characteristics of stress distribution and the location of the maximum stress were analyzed. Moreover,the influence of different parameters on joints was thoroughly discussed. The results show that the bending moment has remarkable influence on the maximum stress. The three main failure modes in the cast-steel joint with three branches are yield of the main tube along the axial direction( M1), local buckling at the connection of the main tube and branches( M2),and tearing out of the branch( M3). M1 happens when the wall thickness is thick under the action of axial force,M2 happens when the ratio of the diameter to its wall thickness is big under the action of axial force,and M3 happens under the action of bending moment.