PSI - Issue 75

Mehdi Ghanadi et al. / Procedia Structural Integrity 75 (2025) 457–466 Mehdi Ghanadi et al./ Structural Integrity Procedia (2025)

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3. Weld quality analysis Traditionally, the quality of welded joints has been assessed manually using mechanical gauges (Hammersberg & Olsson, n.d.; Stenberg et al., 2017a). Digital systems facilitate reliable assessment of weld profiles based on quality standards (Stenberg et al., 2019). In ISO 5817 (ISO 5817:2023 - Welding — Fusion-Welded Joints in Steel, Nickel, Titanium and Their Alloys (Beam Welding Excluded) — Quality Levels for Imperfections, n.d.), weld quality is categorized into quality classes D, C and B, with B as the highest and D as the lowest weld quality. In the current work the test specimens were scanned with a commercial quality assurance system, Winteria® with employing a laser scanning device that moves along the weld seam to capture the 3D geometry and records the weld profile, as shown in Fig. 4. In the current study, the weld quality assessment is based on the weld quality standards ISO 5817:2023 incorporated into the software. The weld geometry parameters such as weld toe radius, weld toe angle, weld throat thickness, weld undercut, and weld leg length were extracted and analysed by using the qWeld module in the Winteria® system. This process is carried out in accordance with algorithms developed by Stenberg et al. (Stenberg et al., 2012), where the weld geometry is converted into detailed geometric definitions, providing input parameters for weld quality evaluation.

Figure 4.Weld quality inspection of a component using the Winteria® system. The laser scanning path is shown in a closeup image in the corner. (Hultgren, 2024) 4. Data Analysis Variations in weld geometry parameters obtained from measurements, are analysed for all specimens, Fig. 5. The welded joint with a 2 mm plate thickness exhibits a larger toe radius, while the 16 mm specimen has a greater weld angle, which is also reflected in the results shown in Fig. 3. As weld quality shifts from quality B to C, the weld toe radius and weld toe angle decrease. This decrease results in a sharper transition between the weld and the base plate. Consequently, this geometric change leads to an increase in stress concentration within the toe region, which can significantly impact fatigue performance. The higher stress concentration in this area makes the structure more susceptible to fatigue failure, highlighting the importance of maintaining optimal weld quality to enhance durability and structural integrity. Imperfection limits by quality level B and C are defined according to ISO 5817 in Fig. 5. For toe radius the imperfection thresholds are defined for plate thickness above 3 mm with weld toe radius equal 1 mm (B90) and 4 mm (B125). Concerning the weld toe angle, the permissible imperfection limits applicable to both 2 mm and 16 mm plate thicknesses are set at 100 for quality level C and 110 for quality level B. According to ISO 5817,