Five angle-ply laminates ([0₄₈], [(±10)₁₂]<sub>s</sub>, [(±20)₁₂]<sub>s</sub>, [(±30)₁₂]<sub>s</sub>, and [(±45)₁₂]<sub>s</sub> with central circular holes were tested under uniaxial compressive loading. The results from these tests show that the [(±45)₁₂]<sub>s</sub> laminate exhibited plastic deformation, with ultimate applied strains exceeding -1%. All other laminates failed in a brittle manner with ultimate strains of less than -0.5%.
A three-dimensional finite element stress analysis was performed for the same laminates. A failure analysis based on the three-dimensional stress tensor polynomial predicted that failure will initiate at the intersection of the ply interface with hole edge for all laminates, and be due to a combination of the out-of-plane and in-plane shear stresses. Use of the state of stress directly on the hole edge in the prediction of laminate failure resulted in predictions of laminate ultimate strengths which were less than experimentally observed values by as much as a factor of ten.
In addition, symmetry considerations for three-dimensional finite element modelling of composite laminates are discussed, and a two-dimensional finite element model based on shear-deformable plate theory is predicted. / M.S.
Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/104298 |
Date | January 1985 |
Creators | Burns, Stephen W. |
Contributors | Engineering Mechanics |
Publisher | Virginia Polytechnic Institute and State University |
Source Sets | Virginia Tech Theses and Dissertation |
Language | English |
Detected Language | English |
Type | Thesis, Text |
Format | xv, 252 leaves, application/pdf, application/pdf |
Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
Relation | OCLC# 13068573 |
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