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Predictions of Poisson's ratio in cross-ply laminates containing matrix cracks and delaminationsA damage-dependent constitutive model for laminated composites has been developed for the combined damage modes of matrix cracks and delaminations. The model is based on the concept of continuum damage mechanics and uses second-order tensor valued internal state variables to represent each mode of damage. The internal state variables are defined as the local volume average of the relative crack face displacements. Since the local volume for delaminations is specified at the laminate level, the constitutive model takes the form of laminate analysis equations modified by the internal state variables. Model implementation is demonstrated for the laminate engineering modulus E(x) and Poisson's ratio nu(xy) of quasi-isotropic and cross-ply laminates. The model predictions are in close agreement to experimental results obtained for graphite/epoxy laminates.
Document ID
19890057944
Document Type
Reprint (Version printed in journal)
Authors
Harris, Charles E. (NASA Langley Research Center Hampton, VA, United States)
Allen, David H. (NASA Langley Research Center Hampton, VA, United States)
Nottorf, Eric W. (Texas A & M University College Station, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Journal of Composites Technology and Research
Volume: 11
ISSN: 0885-6804
Subject Category
STRUCTURAL MECHANICS
Funding Number(s)
CONTRACT_GRANT: AF-AFOSR-84-0067
Distribution Limits
Public
Copyright
Other