Fatigue Damage Analysis of Aluminum Alloy 6061 Based on CT Scanning

Dynamic spatial distribution and evolution of three-dimensional (3D) voids/cracks in engineering materials are crucial information to predict fatigue damage and residual life. A method of fatigue damage analysis was proposed and used to estimate low-cycle fatigue damage. First, multi-stage fatigue damage defects were measured based on x-ray computed tomography (XCT). 3D voids/cracks were reconstructed and analyzed by VG Studio and Diego algorithm. Then, 3D voids/cracks were transferred into finite element model along with material domain for numerical analysis. Thirdly, the damage transformation process was achieved by means of 3D finite element analysis. And the numerical and experimental results were compared. The estimated damage variables in terms of effective elastic modulus were in agreement with experimental results. It is indicated that the proposed numerical prediction method is valid for damage evolution in low-cycle fatigue.