Analysis on the Behavior of Nonpropagating Fatigue Cracks under Steep Stress Gradients. (5th June 2014)

• Record Type: Journal Article
• Authors: Wu, Hao; Lu, Qiuying
• Other Names: Vilar Rui Academic Editor.
• Is Part Of: Advances in materials science and engineering. Volume 2014(2014)
• Publication Date: 2014-06-05
• Subjects: Materials science -- Periodicals; Materials science; Periodicals; 620.11
• DOI: 10.1155/2014/487410
• Languages: English
• ISSNs: 1687-8434

Abstract

Abstract : A mechanism for the formation of nonpropagating fatigue cracks ahead of a notch root is presented. The stress gradients near the elongated notch root along with the propagation of short crack and the resulting nonpropagating crack lengths a npc are estimated. The local stress which is higher than the unnotched material fatigue limit S 0 initiates the crack from a notch root and local steep stress gradient as a very important element leads to the nonpropagating crack. The value of a npc depends on the material properties, and specimen geometry as well as applied loading. The characteristic size of the short crack a 0 which depends on the material properties associates with the fatigue stress concentration factor K f . The estimated values of a npc are in fairly good agreement with the experimental values available.