Numerical simulation of tensile deformation on aluminum alloy FSW lap joints

Fracture behaviour of friction stir welded lap joints in 2A12 aluminum alloy was investigated by strength test.The distribution of stress and strain around the crack tip was calculated by finite element method under stretching forces.Analysis results show that plastic deformation occurs first at crack tip and the maximum plastic deformation is found in crack tip region in upper plate which lead to the fracture of heat-affected zone in upper plate.