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Combined effect of matrix cracking and stress-free edge on delaminationThe effect of the stress-free edge on the growth of local delaminations initiating from a matrix crack in (O sub 2/90 sub 4) sub s and (+/- 45.90 sub 4) sub s glass epoxy laminates is investigated using 3D finite element analysis. The presence of high interlaminar normal stresses at the intersection (corner) of the matrix crack with the stress-free edge, suggests that a mode I delamination may initiate at the corners. The strain energy release rates (G) were calculated by modeling a uniform through-width delamination and two inclined delaminations at 10.6 deg and 45 deg to the matrix crack. All components of G have high values near the free edges. The mode I component of G is high at small delamination length and becomes zero for a delamination length of one-ply thickness. The total G values near the free edge agreed well with previously derived closed form solution. The quasi-3D solutions agreed well with the 3D interior solutions.
Document ID
19920056391
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Salpekar, Satish A.
(Analytical Services and Materials, Inc. Hampton, VA, United States)
O'Brien, T. K.
(U.S. Army, Aerostructures Directorate; NASA, Langley Research Center Hampton, VA, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1991
Subject Category
Structural Mechanics
Accession Number
92A39015
Funding Number(s)
CONTRACT_GRANT: NAS1-18599
Distribution Limits
Public
Copyright
Other

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