高占远　郭彦林

摘要：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。

关键词：Y型相贯节点；极限承载力；牛顿拉普森法；弧长法；焊接残余应力；参数分析

中图分类号：TU392文献标志码：A

Abstract： The welding process of Yjoint was simulated by using thermal structure indirect coupling and birthdeath element in ANSYS. Combined NewtonRaphson method and arclength method， the ultimate bearing capacity of Yjoints was solved， and solution flow was given. The influence of geometric parameters such as the ratio of diameter of branch pipe and diameter of pipe， angle of branch pipe， ratio of diameter and thickness of pipe， on the ultimate bearing capacity of Yjoints with considering welding residual stress was analyzed. Ultimate bearing capacities of Yjoints with welding residual stresses and without welding residual stresses were compared and analyzed. The results show that the ultimate bearing capacity of Yjoint is reduced by welding residual stress； because values of the β are larger， or values of the γ are smaller， or values of the θ are smaller， the ultimate bearing capacity of Yjoint is more reduced. In structural design， to ensure the strength and safety of structure， choosing the suitable diameter and angle of branch pipe， wall thickness of pipe， the effect of welding residual stress on ultimate bearing capacity of Yjoint can be reduced.

Key words： Yjoint； ultimate bearing capacity； NewtonRaphson method； arclength method； welding residual stress； parameter analysis

0引言

钢管结构主要应用于桁架、结构柱、支撑、格构式结构、大跨空间结构等[12]。桁架结构的应用比较广泛，这类结构具有造型美观、布置灵活、受力明确等特点，通过节点将主管和支管连接起来，节点性能的好坏直接影响结构的承载力。节点种类较多，如螺栓球节点、焊接空心球节点、铸钢节点、相贯节点等。相贯节点是常见形式之一，具有构造简单、易于连接、受力性能较好、传力路径清晰、外表美观、易于维护保养、节省用钢量等优点，越来越受到人们的青睐[3]。

相贯节点通过焊接而成，在结构中产生较大的残余应力，对结构的承载力和安全造成影响，因此分析相贯节点的焊接残余应力分布及其对节点静力性能和极限承载力的影响规律对结构的设计和施工是十分有意义的。……