Residual stress evaluation in welded large thin-walled structures based on eigenstrain analysis and small sample residual stress measurement

This paper presents an evaluation method of residual stresses in large welded thin-walled structures based on eigenstrain analysis and small sample residual stress measurement. In this method, small samples containing weld and heat-affected zones are firstly cut from large thin-walled structures, then residual stress in the small samples are measured to determine the welding-induced eigenstrains using a finite element-aided inverse solution. Finally, residual stress in large thin-walled structures are evaluated based on the obtained eigenstrain distribution. The feasibility of the proposed method was validated by evaluating residual stresses in welded plates with different lengths or widths. The method was then applied to evaluating residual stress in a welded skin-stiffener panel. Good agreement between the evaluated residual stress and measurement by diffraction technique has demonstrated the practicability of the method.