【摘要】 针对两种典型的封闭环焊缝焊接——圆盘镶块和平板垂直接管的多道焊焊接进行了三维数值模拟,分析采用子程序来实现高斯分布表征的热源移动,得到了焊接的热循环过程及焊后残余应力分布。分析表明,封闭环焊缝在起焊/收焊区域的残余应力状况复杂,存在较大的环向残余拉应力,往往会诱使焊缝开裂失效。相比而言,接管环焊缝的应力状况更应引起足够的重视。更多还原

【Abstract】 Two typical closed weld,circular patch weld and nozzle weld, were modeled and 3-D multi-pass welding simulation were performed using FEM. User subroutine were used to realized the moving Gauss distribution of welding heat source. The thermal cycle and residual stresses distribution were obtained.The results show that the maximum hoop tensile residual stress exists in the region of the start/stop point of the circular weld for above two models, where the stress distribution is complex and the larger hoop tensile stresses are always regarded as the driven force of weld fracture. As comparison, the case of the nozzle weld needs more attention.更多还原