Effect of different regions on fatigue crack growth behavior of 6005-T6 aluminum alloy metal inert gas (MIG) butt welded joint: experimental and numerical study

This paper presents an experimental and numerical investigation of the fatigue crack growth behavior in different regions of metal inert gas (MIG) butt welded joints of 6005-T6 aluminum alloy. A series of experiments were carried out, including the compact tensile specimen crack growth rate, microstructure, and failure fracture analysis, which reveals the crack growth mechanism in different weld regions. A fracture mechanics numerical model considering geometric features and material inhomogeneity was developed, and the crack growth life results were obtained in agreement with the test. The results show that the microstructure and inhomogeneous material properties significantly affect their crack growth behavior and life distribution. The life distribution of different weld regions was quantified based on the Weibull distribution parameters to guide crack growth life assessment.