Round-robin study on the determination of weld geometry parameters—part B: analysis of welded specimen

Abstract The local geometry of the weld toe or the weld seam has a high influence on the fatigue strength of welded joints. Two main parameters for the geometrical description of the weld toe are the weld toe radius and the weld toe angle. Currently, there is no uniform definition or standardized measurement approach for the assessment of these parameters. For this reason, the presented extensive round-robin (RR) study focusses on the influence of different evaluation techniques and measurement systems regarding the mentioned parameters based on 3D surface scans. In total, 20 participants take part in this two stage RR (19 participants in the second part). In this work, the results of the second part (part B) of the RR, namely the evaluation of weld toe radius and weld toe angle on real welded joints, are presented, where the actual weld toe geometry is not known a priori. For this, 22 data sets were evaluated. The data sets consist of measured values for the radius and angle of the weld toe in relation to the position along the weld seam. In general, significant variations are determined for the evaluated weld geometry parameters, especially for the weld toe radius. It is also shown that the condition of the weld toe transition has a high influence on the parameter. Particularly for weld seams with a low weld toe angle, the measurement results for the radius of the individual participants show high variations. For small weld toe radii, the results are quite comparable between the participants. The results for the weld toe angle are comparable for flat welds, but a wide range of results is observed for sharp weld toes. The degree of automation of the measurement method also has a high influence on the results. The most accurate results are expected from manual measurements, while the fully automatic and semi-automatic methods show larger deviations.