Quantitative characterization on fatigue fracture features of A6005 aluminum alloy welded joints. (November 2021) - Zhang, Zhiyi
Highlights: Reliability estimations of fatigue life and the linear fatigue stress-life model. The changes in fractal dimension and the two-dimensional roughness Ra . Qualitative relationship between fractal dimension and crack propagation rate. Quantitative relationship between the fractal dimension and fatigue life. Abstract: Fatigue performance is important for materials and welded joints in engineering structures. A fatigue test of A6005 aluminum alloy welded joints was conducted. When confidence level was 50%, fatigue lives were reliable for reliability levels of 50% and 97.7%. Statistical F-test evaluation proved that the linear fatigue stress-life model was rational. Metallic oxides or discrete bar-like materials led to crack nucleation. Fractal dimension characterized the fracture features, initially increased and then decreased at all stress levels. However, crack propagation rates were inversely proportional to fractal dimension. Further, fractal dimension integration equalled the fatigue life. A linear relationship was established with a good R 2 obtained 0.978.