采用ANSYS的热-结构间接耦合、生死单元技术模拟Y型相贯节点的焊接过程;将牛顿-拉普森法和弧长法结合,求解Y型相贯节点极限承载力,给出求解流程;分析支管外径与主管外径比、支管倾角、主管径厚比等几何参数对Y型相贯节点极限承载力的影响,将考虑和不考虑焊接残余应力的计算结果进行对比分析。研究结果表明:焊接残余应力降低了Y型相贯节点的极限承载力;支管外径与主管外径比β越大,主管的径厚比γ越小,支管倾角θ越小,则Y型相贯节点极限承载力降低越多;结构设计时,保证强度和安全的前提下选择合适的支管外径、主管壁厚和支管倾角,可减小焊接残余应力对Y型相贯节点极限承载力的影响。 The thermal-structural indirect coupling and ANSYS are used to simulate the welding process of Y-shaped joints. The Newton-Laplace method and arc-length method are combined to solve the ultimate bearing capacity of Y-shaped joints, and the solution process is given. The influence of geometrical parameters such as branch outer diameter to branch outer diameter ratio, branch dip angle and main tube diameter to thickness ratio on the ultimate bearing capacity of Y-shaped cross-section joints is analyzed. The comparative analysis of calculation results with and without consideration of welding residual stress is carried out. The results show that the residual stress of welding decreases the ultimate bearing capacity of Y-shaped cross-section joints. The larger the ratio of the outside diameter of branch pipe to the outside diameter of main pipe is, the smaller the thickness-thickness ratio γ of main pipe is and the smaller the inclination of branch pipe is. The lower the ultimate bearing capacity of the joints is; the appropriate outer diameter of the branch pipe, the wall thickness of the branch pipe and the dip angle of the branch pipe can be selected under the premise of structural design, ensuring the strength and safety, and the ultimate bearing capacity of the Y- influences.