Issue 35

A. Mehmanparast et alii, Frattura ed Integrità Strutturale, 35 (2016) 125-131; DOI: 10.3221/IGF-ESIS.35.15 128 Double V-Groove Welded Plates A numerical sensitivity analysis was carried out by Teng T-L [11] to investigate the influence of welding sequence on residual stress distribution in SAE 1020 thick plates. Two-dimensional finite element analyses were performed in this work to simulate various combinations of multi-pass butt welding sequence. As seen in Fig. 5, simulations were conducted to predict residual stresses induced in double V-groove welded plates for three different cases of welding sequences. In this study the V-grooves at both sides of the welded plates were assumed to be the same size. The predicted residual stresses from this study were plotted against “distance from the weld center” and the results are presented in Fig. 6. It can be observed in Fig. 6 that the stress trends and peak values are relatively sensitive to the welding sequence and the changes in residual stresses are more pronounced in transverse (along X axis) direction compared to the through thickness (along Y axis) direction. The predicted results in this figure show that the highest and the lowest peak tensile residual stresses were found in Case (C) and Case (A) of welding sequences, respectively. Comparing the transverse residual stress trends at the center of the weld region in Fig. 6(b) it can be seen that the residual stress value predicted for Case (C) is almost double of that of predicted for Case (A). Comparison of the residual stresses predicted in Fig. 6(a) and (b) shows that the through thickness (along Y axis) peak tensile residual stresses for all three cases of welding sequences have been found much larger than those of predicted along X direction. Finally seen in Fig. 6 is that the through thickness (along Y axis) residual stress trend shows tensile stresses near the weld bead and compressive stresses away from the weld bead, whereas no compressive residual stress field can be observed in transverse (along X axis) residual stresses. X Y Z Figure 5 : Different cases of multi-pass butt welding sequence [11]. Y Through Thickness Residual Stress σ Y (Pa) (a) (b) Figure 6 : Predicted residual stress components along (a) Y direction (b) X direction , for three cases of welding sequences [11].