For investigating the applicability of shell elements for FE analysis of distortion and residual stress generated by fillet welding, a series of experiments and numerical analyses were carried out. Considering the temperature distribution in the thickness direction, the heat input model for fillet welding with changing the thickness of shell elements was proposed. The prediction accuracy of the welding out-of-plane deformation and residual stress by the model with shell elements was within 12% and 17% of those of the model with solid elements respectively. The computing time by the model with shell elements was around 4% to 13% of that by the model with solid elements.
