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The mechanics of delamination in fiber-reinforced composite materials. I - Stress singularities and solution structureThe fundamental mechanics of delamination in fiber composite laminates is studied. Mathematical formulation of the problem is based on laminate anisotropic elasticity theory and interlaminar fracture mechanics concepts. Stress singularities and complete solution structures associated with general composite delaminations are determined. For a fully open delamination with traction-free surfaces, oscillatory stress singularities always appear, leading to physically inadmissible field solutions. A refined model is introduced by considering a partially closed delamination with crack surfaces in finite-length contact. Stress singularities associated with a partially closed delamination having frictional crack-surface contact are determined, and are found to be different from the inverse square-root one of the frictionless-contact case. In the case of a delamination with very small area of crack closure, a simplified model having a square-root stress singularity is employed by taking the limit of the partially closed delamination. The possible presence of logarithmic-type stress singularity is examined; no logarithmic singularity of any kind is found in the composite delamination problem. Numerical examples of dominant stress singularities are shown for delaminations having crack-tip closure with different frictional coefficients between general (1) and (2) graphite-epoxy composites. Previously announced in STAR as N84-13221
Document ID
19840039478
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Wang, S. S.
(Illinois Univ. Urbana, IL, United States)
Choi, I.
(Illinois, University Urbana, IL, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1983
Subject Category
Composite Materials
Report/Patent Number
AD-B177722L
Accession Number
84A22265
Funding Number(s)
CONTRACT_GRANT: NAG1-286
Distribution Limits
Public
Copyright
Other

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