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AXIAL FATIGUE OF ADHESIVELY‐BONDED LAMINATES
Author(s) -
ALIC J. A.
Publication year - 1979
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1979.tb01348.x
Subject(s) - materials science , composite material , epoxy , tension (geology) , bending , composite laminates , fatigue testing , aluminium , alloy , stress concentration , stress (linguistics) , structural engineering , fracture mechanics , ultimate tensile strength , composite number , linguistics , philosophy , engineering
Fatigue tests with axial tension loading ( R = 0.1) have been performed on aluminum alloy laminates having 8 and 22 layers. The laminates were similar to those previously reported for bending fatigue, having 7075–T6 layers joined by Hysol EA9410 epoxy. Both unnotched and notched (K t = 2.42) specimens were tested. Fatigue lifetimes for both 8‐ and 22‐layer laminates were significantly less than for monolithic specimens tested for comparison, the differences increasing as the maximum stress decreased. This was true for both the notched and unnotched tests and is the reverse of the trends previously found in bending. While the unexpected inferiority of laminates in tension fatigue appears to be at least partially a result of material variability, it is also evident that changing the type of loading can have unpredictable effects on the comparative fatigue performance of laminates. For both unnotched and notched laminates, different layers continued to crack at different locations, demonstrating the uncoupled nature of the fatigue process in the various layers.