Parametric finite element analysis of stress evolution during friction stir welding

Abstract

It is well known that the residual stress of the friction-stir-welded joint affects the fatigue strength and life, and the corrosion performance. In this paper, a three-dimensional finite element model is established to study the thermal history and stress evolution in the butt welding of aluminium alloy 6061-T6, which will comprehensively provide insight into the friction-stir-welding process. The mechanical action of the shoulder and the thermomechanical effect of the tool (including shoulder and probe) are included in the comprehensive model. The orthogonal stress evolution of the weld is given in this paper. The relationship between the calculated residual stresses of the weld and the process parameters such as the tool traverse and rotational speeds, and the fixture release are investigated and presented.