Improving ISO 5817 butt weld fatigue criteria with 3D geometry and stress-life residuals

Kurzfassung

The fatigue strength of welded joints is highly sensitive to local geometric variations along the weld seam; however, current standards, such as ISO 5817, are designed for manual measurements and lack guidance on how to utilize the detailed, highresolution geometric distributions now obtainable through advanced scanning technologies. This study investigates 3Dscanned butt welds, extracting key geometric features using 2D slicing techniques. Different correlation methods were employed to quantify the relationship between each feature and fatigue life, enabling the identification of the most influential parameters. These descriptors were further analyzed using the residuals of a baseline stress-life regression model to evaluate their influence on fatigue strength, offering insights for improving the weld quality criteria. The minimum nominal values of overfill and weld toe flank angle emerged as significant parameters. The proposed approach introduces new data-driven guidelines that align with the philosophy of ISO 5817 while also addressing the challenges of generalizing these findings.