An evaluation on high cycle fatigue fracture characteristics of 2024-T351 Al alloy with different surface defects. (January 2022)

• Record Type: Journal Article
• Authors: Liu, A.; Xu, Z.W.; Liang, Z.; Wang, X.S.
• Is Part Of: Mechanics of materials. Volume 164(2022)
• Publication Date: 2022-01
• Subjects: 2024-T351 Al alloy -- S–N curve -- Residual stress -- Fatigue limit -- 3D K-T diagram; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2021.104133
• Languages: English
• ISSNs: 0167-6636

Abstract

Abstract: The integrity of structural components and fatigue performances of materials directly affect the service life in their applications. 2024-T351 Al alloy is one of main series aluminum alloys for manufacturing which are prone to be pitted during aircraft applications. Therefore, it is significant to study the influence of surface defects on the fatigue damage behaviors and performances of 2024-T351 Al alloy. In this paper, the influence of the surface artificial defect on the high cycle fatigue (HCF) behavior and fracture characteristics of 2024-T351 Al alloy was quantitatively discussed. A fatigue limit prediction method of 2024-T351 Al alloy with the different surface defects was proposed by using the mensurable geometric parameters of defect. These estimated upper and lower fatigue limits were validated by the numerous fatigue test data. These results indicated that the estimated fatigue (upper and lower) limits were superior to that predicted by using Murakami formula. A safe fatigue loading domain of 2024-T351 Al alloy with surface defects was established by using three-dimensional Kitagawa-Takahashi (3D K-T) diagram. Highlights: The slope α is about 0.012 in N f exp ( α σ ) = C for HCF of 2024-T351 Al alloy with different surface defects. The indentation defects can induce the fatigue multi-cracking positions in higher stress amplitude. The residual stress change near the indentation defect was quantitatively by using FEM. The upper and lower fatigue limits can be quantitatively estimated by using the parameters of defects. A 3D K-T diagram of 2024-T351 Al alloy as a safe domain of fatigue was obtained.