Numerical Assessment of High-Cycle Fatigue Behavior of Notched Cast Aluminum Alloy A357-T6 Based on Affected Depth

This article aims to estimate the high-cycle fatigue (HCF) behavior of a circumferential notched A357-T6 cast aluminum alloy based on the affected depth (AD) approach. This technique is applied as a useful way to anticipate the fatigue life of notched components using the multiaxial fatigue criterion proposed by Crossland. Simulations of the cyclic finite element (FE) calculations in Abaqus involve implementing an elastic–plastic combined Chaboche model. Calculations lead to determining the Kitagawa–Takahashi diagram for this type of defect under the load ratio R_σ = 0.1, showed good agreement with the experimental data. The study provides a clear quantification of the effect of the notch on fatigue resistance. The fatigue limit of the notched specimen decreases by about 16% when the radius of the notch is equal to 3 m. This cast aluminum alloy has revealed a low sensitivity to notches. The notch sensitivity factor (q) was estimated for different defects and conditions, indicating that a factor value closer to zero suggests the material is insensitive to the notch. Additionally, the findings of Takaji’s coarse microstructures are contrasted with the evaluation of the notch sensitivity factor q for fine microstructures. The findings show that the fatigue resistance of notched A357-T6 specimens is not significantly impacted by the microstructural scale, suggesting that fatigue initiation in this alloy is primarily controlled geometrically.