National Aerospace Laboratory
University of Electro-Communications Dept. of Mechanical and Control Engineering, Faculty of Electro-Communications
University of Electro-Communications Graduate School
National Aerospace Laboratory Structures Division
National Aerospace Laboratory Structures Division
The objective of this study is to investigate the properties of fatigue crack growth in a GLARE3-5/4 fiber/metal laminate and the validity of methods for analyzing the fatigue crack growth of fiber/metal laminates. GLARE3-5/4 consists of five thin sheets of 2024-T3 aluminum alloy and four layers of (0/90) glass/epoxy. Centrally notched specimens were fatigue tested under constant amplitude loading and crack length was measured using the DC potential drop method. The size of the delamination produced between aluminum alloy sheets and fiber adhesive layers was measured from C-scan pictures taken around a fatigue crack. The following conclusions were drawn. (1) The scatter in fatigue crack growth lives was a little higher than that of a 2024-T3 aluminum alloy. (2) The relationship between crack growth rate, da/dN, versus stress intensity factor range, Delta K, obtained on the assumption of a monolithic material was different from that of a single 2024-T3 aluminum alloy machined from the GLARE and showed the maximum stress dependence. (3) The relationship between da/dN and Delta K(sub fin), the stress intensity factor range analyzed by Marissen on the basis of a fiber bridging effect, approximately agreed with that of a single 2024-T3 aluminum alloy specimen regardless of the maximum stress.
ファイバー/メタル積層材料GLARE3-5/4の疲労き裂進展特性評価
naltr0001366.pdf
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