In welding fixture design, ensuring accessibility for manual Metal Active Gas (MAG) welding is essential for achieving required weld quality, proper welding angles, operator efficiency, and overall manufacturability. Manual welding operations depend on handheld torches, where limitations in reachability, torch orientation, and confined working spaces can significantly impact production feasibility.
Automotive body structures are typically composed of numerous small and complex components within a largely monolithic assembly. For welding such smaller parts, hand jigs are used as independent tools to ensure proper positioning and stability. Accessibility and usability of these hand jigs play a crucial role, particularly in tight and restricted areas, directly affecting operator ergonomics and weld consistency. Traditionally, validation of welding torch accessibility and hand jig usability is performed during the physical try-out stage, often leading to late identification of design issues, fixture modifications, increased lead time, and higher development costs.
This study proposes a Virtual Reality (VR)-based validation methodology to evaluate manual MAG welding accessibility and hand jig usability during the fixture design phase. CAD models of fixtures and components are integrated into an immersive VR environment, enabling real-time simulation of operator interaction. Critical parameters such as reachability, collision detection, welding angle, torch orientation, operator posture, and hand jig accessibility are assessed. The VR-based approach enables realistic evaluation of human interaction and ergonomic conditions, which are not effectively captured using conventional simulation tools. Early validation through VR significantly reduces design iterations, minimizes rework, and improves fixture design robustness.
Overall, the proposed methodology enhances productivity, reduces costs, and accelerates project execution in welding fixture development.
To provide a quantitative ergonomic assessment, the study introduces an Ergonomic Accessibility Index based on Green and Red Zone weld classification. In the Bus Middle UB fixture case study, the EAI improved from 70.8% to 95.8% after the product geometry was repositioned upward, demonstrating improved welding accessibility and operator ergonomics.