dc.contributor.author	Lavoie, J. André	en
dc.contributor.committeechair	Morton, John	en
dc.contributor.committeecochair	Curtin, William A. Jr.	en
dc.contributor.committeemember	Cramer, Mark S.	en
dc.contributor.committeemember	Jackson, Karen E.	en
dc.contributor.committeemember	Reifsnider, Kenneth L.	en
dc.contributor.committeemember	Morris, Don H.	en
dc.contributor.department	Engineering Science and Mechanics	en
dc.date.accessioned	2014-03-14T20:21:55Z	en
dc.date.adate	1997-04-04	en
dc.date.available	2014-03-14T20:21:55Z	en
dc.date.issued	1997-04-04	en
dc.date.rdate	1997-04-04	en
dc.date.sdate	1998-07-18	en
dc.description.abstract	The damage development and strength of ply-level scaled carbon/epoxy composite laminates having stacking sequence of [+Tn/-Tn/902n]s where constraint ply angle, T, was 0, 15, 30, 45, 60, and 75 degrees, and size was scaled as n=1,2,3, and 4, is reported in Part I. X-radiography was used to monitor damage developments. First-ply failure stress, and tensile strength were recorded. First-ply failure of the midplane 90 deg. plies depended on the stiffness of constraint plies, and size. All 24 cases were predicted using Zhang's shear-lag model and data generated from cross-ply tests. Laminate strength was controlled by the initiation of a triangular-shaped local delamination of the surface angle plies. This delamination was predicted using O'Brien's strain energy release rate model for delamination of surface angle plies. For each ply angle, the smallest laminate was used to predict delamination (and strength) of the other sizes. The in-situ tensile strength of the 0 deg. plies within different cross-ply, and quasi-isotropic laminates of varying size and stacking sequence is reported in Part II. No size effect was observed in the strength of 0 deg. plies for those lay-ups having failure confined to the gauge section. Laminates exhibiting a size-strength relationship, had grip region failures for the larger sizes. A statistically significant set of 3-point bend tests of unidirectional beams were used to provide parameters for a Weibull model, to re-examine relationship between ultimate strength of 0 deg. plies and specimen volume. The maximum stress in the 0 deg. plies in bending, and the tensile strength of the 0 deg. plies (from valid tests only) was the same. Weibull theory predicted loss of strength which was not observed in the experiments. An effort to model the durability and life of quasi-isotropic E-glass/913 epoxy composite laminates under steady load and in an acidic environment is reported in Part III. Stress-rupture tests of unidirectional coupons immersed in a weak hydrochloric acid solution was conducted to determine their stress-life response. Creep tests were conducted on unidirectional coupons parallel and transverse to the fibers, and on ±45°. layups to characterize the lamina stress- and time-dependent compliances. These data were used in a composite stress-rupture life model, based on the critical element modeling philosophy of Reifsnider, to predict the life of two ply-level thickness-scaled quasi-isotropic laminates.	en
dc.description.degree	Ph. D.	en
dc.format.extent	x, 145 leaves	en
dc.format.mimetype	application/pdf	en
dc.identifier.other	etd-4131162939721181	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-4131162939721181/	en
dc.identifier.uri	http://hdl.handle.net/10919/30510	en
dc.language.iso	en	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	etd-part1.pdf	en
dc.relation.haspart	etd-part2.pdf	en
dc.relation.haspart	etd-part3.pdf	en
dc.relation.haspart	etd_full.pdf	en
dc.relation.isformatof	OCLC# 38726086	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	stress-corrosion cracking	en
dc.subject	stress relaxation	en
dc.subject	strength scaling	en
dc.subject	size effects	en
dc.subject	microcracking	en
dc.subject	first-ply failure	en
dc.subject	delamination	en
dc.subject	composite material	en
dc.subject	weibull statistics	en
dc.subject	tension testing	en
dc.subject	flexural testing	en
dc.subject	carbon/epoxy	en
dc.subject	glass/epoxy	en
dc.subject	creep	en
dc.subject	stress0cupture	en
dc.subject	creep-rupture	en
dc.subject	durabilty	en
dc.subject	life	en
dc.subject.lcc	LD5655.V856 1997.L386	en
dc.title	Scaling Effects on Damage Development, Strength, and Stress-Rupture Life on Laminated Composites in Tension	en
dc.type	Dissertation	en
dc.type.dcmitype	Text	en
thesis.degree.discipline	Engineering Science and Mechanics	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Ph. D.	en

Scaling Effects on Damage Development, Strength, and Stress-Rupture Life on Laminated Composites in Tension

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