Arc Efficiency Assisted Finite Element Model for Predicting Residual Stress of TIG Welded Sheet

Predicting and controlling residual stresses are critical issues in welding engineering. With advancements in computer technology, a numerical simulation technique can predict welding residual stress. To accurately simulate temperature and stress fields, the thermal cycle obtained from the finite element model must be in coincidence with an actual heat source. This study performed a Gaussian distribution of the heat flux with an effective arc radius that was selected for the finite element analysis to accurately describe the distributive nature of the heat source provided by the welding arc. The results showed that arc efficiency has an effect on temperature history during welding. The computational results of the temperature history and residual stress showed very good agreement with the corresponding experimental data. This study proposes that the simulation errors in finite element analysis can be eliminated by adjusting the Gaussian distributed spatial heat source and arc efficiency.