Experimental and numerical study on failure of resistance spot welded AA6061-T6 joint under tensile-shear test using GTN model

The main purpose of this study is experimental and numerical investigation on failure of resistance spot welded Al6061-T6 joint under tensile-shear test using damage model. Today using aluminum alloys in automobiles’ structure is increases to reduce weight and fuel consuming. The strength of an automobile’s structure completely depends on the quality of the strength and the quality of the welded joints. So, study the strength of these welded joints is very essential to obtain safe structures. In this study Gurson-Tevergaard-Needleman (GTN) model is utilized to study the failure of welded joint. A finite element (FE) model is developed to simulate failure of the welded joint under tensile-shear test. To validate the FE model, 7 series of samples are welded with different welding parameters (minimum 5.72 mm and maximum 8.41 mm) to obtain altered nugget size. The comparison between experimental and FE model results’ shows that the different between results is approximately 2% and the GTN model has a good reliability to predict the failure force. In addition the results show that the FE model can predict truly the starting of failure in the welded joint.