Analysis of aluminum sheets with multiple sites damage based on fatigue tests and DIC technique. (April 2018)

• Record Type: Journal Article
• Authors: Chen, Yajun; Sun, Shengjie; Ji, Chunming
• Is Part Of: International journal of fatigue. Volume 109(2018)
• Page Start: 37
• Page End: 48
• Publication Date: 2018-04
• Subjects: Multiple sites damage -- Digital image correlation -- Non-collinear crack -- Fatigue; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2017.12.008
• Languages: English
• ISSNs: 0142-1123

Abstract

Graphical abstract: Highlights: Fatigue life of MSD specimen increases with the increase of hole spacing. Crack propagation status can be obtained based on DIC technology. Cracks propagate firstly by Mode I type, and then by hybrid expansion. The fatigue life estimation method based on ABAQUS and Paris formula is reliable. Abstract: In order to study the multiple sites damage (MSD) under fatigue loading which was occurring in the airframe of aging aircraft, the digital image correlation (DIC) technique was used to evaluate MSD in the hollow pre-notched specimen with 2024-T4 aluminum alloy subjected to cyclic loading conditions. Fatigue lives and displacement fields obtained from digital images recorded during fatigue tests were used to analyze the crack initiation and propagation. The results show that the fatigue life increases with the increase of hole spacing and that the case of collinear cracks becomes more dangerous than that of non-collinear cracks for MSD specimens. The experiments and DIC analyses were carried out to validate the type of fatigue crack propagation, firstly by mode I, and then by the mode I and II with hybrid expansion. Based on the combination of ABAQUS and Paris formula, stress intensity factors (SIF) and fatigue lives were acquired, which provide the conservative estimation of fatigue life.