Experimental Determination of Welding Residual Stress Through Image Processing Technique

Residual stresses induced by gas tungsten arc welding (GTAW) significantly influence the structural integrity and service life of welded components. Traditional residual stress measurement techniques, such as X-ray diffraction and hole-drilling, are often complex, costly, or destructive, necessitating the development of alternative methods. This study proposes a nondestructive, cost-effective approach for residual stress analysis using image processing techniques. By comparing pre- and post-welded images of laser-engraved specimens, surface deformations were quantified to determine longitudinal and transverse residual stresses. The experimental results demonstrated good agreement with validated numerical simulations, with maximum deviations of approximately 10.5% for longitudinal stresses and 8.1% for transverse stresses at peak stress locations. Compared to conventional methods, the proposed technique offers enhanced efficiency and accessibility, making it suitable for industrial applications such as aerospace and automotive manufacturing. This research highlights the potential of image processing for residual stress evaluation and emphasizes the importance of future advancements in standardization and real-time application development.