Determination of welding stress and distortion in discontinuous welding by means of numerical simulation and comparison with experimental measurements

Discontinuous welding is the most common welding type used in the fabrication of structural members in shipbuilding, automobile and other industries. Fillet-welded joints usually suffer from various welding deformation patterns, such as longitudinal shrinkage, transverse shrinkage, angular distortion and longitudinal bending. Welding deformation has negative effects on fabrication accuracy, external appearance and various strengths of the welded structures. This study describes the thermal elasto-plastic analysis using finite element techniques to analyze the thermo-mechanical behavior and evaluate the residual stresses and distortion of 5A06 aluminum alloy structure in discontinuous welding. Furthermore, this work employs the technique of submodeling and substructure to guarantee the simulation accuracy and improve computational efficiency. Also discussed are the effects of welding sequence and weld length on the residual stresses and distortions. In addition, the generation mechanism of angular distortion is clarified through numerical simulation.