Investigation of the effective parameters on welding residual stress in GTAW of aluminum cylindrical shell

The present work aims to study the influence of different geometrical, technological, and material parameters on residual stress in tungsten inert gas butt-welded aluminum cylinder. In order to present a simple analytical model to estimate the welding residual stress, the Taguchi L18 array has been employed with one 6-level factor and four 3-level factors. A 3D coupled thermo-mechanical finite element model considering temperature-dependent material properties has been developed to determine the welding residual stress in all experiments. The numerical model has been validated using the hole-drilling method. Using statistical analysis, the order of factors based on their effect on residual stress has been determined as yield strength, length, thickness, heat input, and finally diameter. The residual stress increases with an increase in yield strength, diameter, and heat input, while decreases with an increase in thickness. Contribution of each parameter on residual stress has been specified using variance analysis; yield strength with 99.6% contribution is the most significant factor, while diameter has insignificant impact. Finally, high accuracy equations have been proposed to calculate the welding residual stress.