Digital visual inspection of welded joints for fatigue assessment and post-weld treatment

This paper explores the use of digital visual testing (D-VT) for quality assurance and to assess weld surface geometry and its impact on the fatigue performance in welded joints. Traditional methods, reliant on manual audits, lack precision and efficiency, often failing to capture subtle variations that influence fatigue strength. This study highlights the advantages of advanced digital tools, such as high-resolution laser scanning, for accurate weld surface geometry measurements. The integration of these measurements with probabilistic and numerical modelling enhances fatigue life predictions and reduces uncertainty. Additionally, robotic post-weld treatments, including TIG remelting and HFMI, are examined for their ability to improve fatigue strength through automated, precision-driven interventions. The findings demonstrate that these methods significantly enhance the reliability and sustainability of structural designs by addressing the variability inherent in welding processes. The results further indicate that the weld toe radius requirements in ISO 5817 Annex B reduce the likelihood of high local stress, whereas sharper transitions may still yield low stresses but with significantly higher variability, and parameters such as weld toe angle show no strong independent trend, emphasising the role of combined geometric effects.