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dc.contributor.authorPatel, Sneha Rameshen
dc.date.accessioned2014-03-14T20:40:30Zen
dc.date.available2014-03-14T20:40:30Zen
dc.date.issued1999-06-16en
dc.identifier.otheretd-062499-200746en
dc.identifier.urihttp://hdl.handle.net/10919/33736en
dc.description.abstractThe objective of this project was to evaluate and model the effects of moisture, temperature, and combined hygrothermal aging on the durability of a graphite/epoxy woven composite material system. Imposed environmental and aging conditions were considered to be representative of service conditions for the engine of an advanced subsonic aircraft for which the composite system is a candidate material. The study was designed such that the results could be used in a residual strength based life prediction approach that accounted for both the mechanical fatigue and environmental conditions. Damage mechanisms and failure modes were determined through fatigue testing, residual strength testing, and nondestructive evaluation. The experimental data generally revealed little effect of environment on strength degradation during fatigue despite notable differences in damage accumulation processes. Modeling efforts were concentrated on initial stiffness, moisture uptake, and residual strength prediction, where the results from the first two efforts were intended to generate inputs for the life prediction. The Ishikawa and Chou fiber undulation and bridging model [22] was shown to provide an accurate stiffness prediction and was subsequently used in parametric studies to determine the effect of weave architecture and geometry. A moisture uptake model developed by Roy [16] for laminates containing single direction cracks was extended to predict moisture uptake in laminates containing cracks in directions parallel and transverse to the loading direction. The life prediction approach was based on ideas developed by Reifsnider and colleagues [36,37,43]. The intention in this case was to use the critical element paradigm to predict the combined effects of alternating environmental (temperature and moisture) conditions imposed during fatigue. Since experimental results indicated that temperature and moisture did not significantly affect the strength and life of the material, a successful life prediction analysis was performed as a function of only fatigue stress level and cycles.en
dc.publisherVirginia Techen
dc.relation.haspartkjl.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCompositesen
dc.subjectWovenen
dc.subjectFatigueen
dc.subjectEnvironmentalen
dc.subjectDurabilityen
dc.titleDurability of Advanced Woven Composites in Aerospace Applicationsen
dc.typeThesisen
dc.contributor.departmentEngineering Mechanicsen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineEngineering Mechanicsen
dc.contributor.committeechairCase, Scott W.en
dc.contributor.committeememberReifsnider, Kenneth L.en
dc.contributor.committeememberLesko, John J.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-062499-200746/en
dc.date.sdate1999-06-24en
dc.date.rdate2000-06-26en
dc.date.adate1999-06-26en


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