Active dynamic response tuning of adaptive composites utilizing embedded nitinol actuators

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dc.contributor.authorBarker, Daniel Keithen
dc.contributor.committeechairRogers, Craig A.en
dc.contributor.committeememberRobertshaw, Harry H.en
dc.contributor.committeememberLeonard, Robert G.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T20:32:22Zen
dc.date.adate2009-03-04en
dc.date.available2014-03-14T20:32:22Zen
dc.date.issued1989-07-04en
dc.date.rdate2009-03-04en
dc.date.sdate2009-03-04en
dc.description.abstractAdaptive composites utilizing embedded nitinol fibers have the unique ability to change their material properties, induce large internal distributed forces in a structure, and can modify the stress and strain distribution within a structure in a controlled manner. In this study, nitinol fibers are embedded in graphite-epoxy and are used as distributed actuators to actively tune the dynamic response of clamped-clamped beams. The natural frequencies of clamped-clamped nitinol composite beams are shown, experimentally. to increase linearly as a function of temperature. Beams with nitinol volume fractions of 5% 10%, and 15% can increase their first natural frequency by factors of 1.7, 2.5, and 3.0 respectively. Classical lamination theory is used to formulate a mathematical model of the dynamic response which includes the adaptive properties of the embedded nitinol fibers as a function of temperature, as well as the thermal aspects of the matrix material. Experimental characterization of nitinol for use as constrained thermosets is performed and the results are used in the mathematical model. The mathematical model is used to calculate the natural frequencies of clamped-clamped nitinol composite beams and the results are compared to experimental results. It is clear that adaptive composites represent a new concept in active control of structural responses and may act as a catalyst for future developments in both material and structures technology. Demonstrating, experimentally and computationally, the ability to alter the dynamic response using unique adaptive qualities will hopefully inspire new material/structural interaction paradigms.en
dc.description.degreeMaster of Scienceen
dc.format.extentxiii, 195 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-03042009-041038en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-03042009-041038/en
dc.identifier.urihttp://hdl.handle.net/10919/31411en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1989.B2735.pdfen
dc.relation.isformatofOCLC# 20442364en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1989.B2735en
dc.subject.lcshComposite materialsen
dc.subject.lcshLaminated materialsen
dc.titleActive dynamic response tuning of adaptive composites utilizing embedded nitinol actuatorsen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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