Fast finite element stress prediction for large thick-wall welded cylinder with angle-inserting elbow

Facing a huge memory space and long calculating period in finite element calculation for large thick-wall welded structure, three predictor models based on software ANSYS with simplification of bead number, moving heat source, and both of them respectively are presented. Under the three simplifications, the residual stress and the process stress of the welded cylinder with angle-inserting elbow and thickness of 125 mm are evaluated, and as a result, the similarities and differences for the welding stress are obtained. It shows that the residual stress in simplified bead model has greater error than that by simplified moving heat source model in direction of bead filled, and the stress in simplified moving heat source model has greater error than that by simplified bead model in the same bead plane. The process peak stress increases in case of simplified moving heat source model, and the process stress of the joint with many beads or a very long welding time is affected more significantly by the simplified bead model.