Digital 3DLD Technology for Objective Evaluation of Welder Qualification and Its Application at the ARC CUP IWC International Welding Competition

Abstract

This paper presents a digital technology for evaluating practical welding skills based on 3D laser diagnostics of weld surface geometry (3DLD). The technology compares the real weld surface with a virtual defect free reference profile calculated using the fundamental Laplace capillarity equation. Welder qualification is expressed through the WQI (Welder Qualification Index), an integral criterion quantifying deviations of the real weld profile from the reference corridor. The 3DLD technology was first applied at the ARC CUP IWC International Welding Competition (Shanghai, 2017) and was officially included in the Technical File in 2018–2019. The paper presents examples of weld evaluation, comparison with traditional expert assessment, and visualization of weld surface deviations. It is demonstrated that 3DLD provides objective, reproducible, and automated evaluation of practical welding skills, eliminates subjectivity, and enables digital ranking of welders in national and international competitions.