{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/45317"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/45317","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Measurement of ultrasonic wave mode transition in unidirectional graphite/epoxy composites","abstract":"The wave propagation mechanism of mode transitions was studied in unidirectional composite materials. Theoretical calculations were compared with experimental measurements. Mode transitions occur when the wave vector orientation is varied in unidirectional samples of T300/5208 graphite/epoxy composite with a 0.6 fiber volume fraction. The mode transition occurs at 51.85° wave vector orientation with respect to the fiber direction. Energy flux deviation and particle displacement directions and amplitudes were also compared with theory. To show this mode transition, an attenuation study was performed. The attenuation coefficient, measured in units of reciprocal time, does not appear to depend on the wave vector orientation and the wave type (quasi-transverse and quasi-longitudinal waves) at 5 MHz frequency. But the attenuation coefficient, expressed in units of reciprocal length, does depend on the wave type and the wave vector orientation because the wave velocity is included in the calculation of this coefficient.","abstract_html":"The wave propagation mechanism of mode transitions was studied in unidirectional composite materials. Theoretical calculations were compared with experimental measurements. Mode transitions occur when the wave vector orientation is varied in unidirectional samples of T300/5208 graphite/epoxy composite with a 0.6 fiber volume fraction. The mode transition occurs at 51.85° wave vector orientation with respect to the fiber direction. Energy flux deviation and particle displacement directions and amplitudes were also compared with theory. To show this mode transition, an attenuation study was performed. The attenuation coefficient, measured in units of reciprocal time, does not appear to depend on the wave vector orientation and the wave type (quasi-transverse and quasi-longitudinal waves) at 5 MHz frequency. But the attenuation coefficient, expressed in units of reciprocal length, does depend on the wave type and the wave vector orientation because the wave velocity is included in the calculation of this coefficient.","abstract_has_math":false,"creators":["Vandenbossche, Benoit"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Engineering","degree_department":"Materials Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Kriz, Ronald D."],"committee_members":["Gordon, Ronald S.","Hendricks, Robert W.","Henneke, Edmund G."],"year":1991,"date_issued":"1991","date_published":"1991","updated_at":"2026-07-22T22:18:42Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-10242009-020340"],"render_values":[{"text":"etd-10242009-020340","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/45317","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Kriz, Ronald D."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Gordon, Ronald S.","Hendricks, Robert W.","Henneke, Edmund G."]},{"key":"dc:contributor.department","label":"Department","values":["Materials Engineering"]},{"key":"dc:creator","label":"Author","values":["Vandenbossche, Benoit"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:48:13Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:48:13Z","2009-10-24"]},{"key":"dc:date.issued","label":"Date","values":["1991"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-10242009-020340"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/45317"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The wave propagation mechanism of mode transitions was studied in unidirectional composite materials. Theoretical calculations were compared with experimental measurements. Mode transitions occur when the wave vector orientation is varied in unidirectional samples of T300/5208 graphite/epoxy composite with a 0.6 fiber volume fraction. The mode transition occurs at 51.85° wave vector orientation with respect to the fiber direction. Energy flux deviation and particle displacement directions and amplitudes were also compared with theory. To show this mode transition, an attenuation study was performed. The attenuation coefficient, measured in units of reciprocal time, does not appear to depend on the wave vector orientation and the wave type (quasi-transverse and quasi-longitudinal waves) at 5 MHz frequency. But the attenuation coefficient, expressed in units of reciprocal length, does depend on the wave type and the wave vector orientation because the wave velocity is included in the calculation of this coefficient."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Measurement of ultrasonic wave mode transition in unidirectional graphite/epoxy composites"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Kriz, Ronald D."],"dc:contributor.committeemember":["Gordon, Ronald S.","Hendricks, Robert W.","Henneke, Edmund G."],"dc:contributor.department":["Materials Engineering"],"dc:creator":["Vandenbossche, Benoit"],"dc:date.accessioned":["2014-03-14T21:48:13Z"],"dc:date.available":["2014-03-14T21:48:13Z","2009-10-24"],"dc:date.issued":["1991"],"dc:description.abstract":["The wave propagation mechanism of mode transitions was studied in unidirectional composite materials. Theoretical calculations were compared with experimental measurements. Mode transitions occur when the wave vector orientation is varied in unidirectional samples of T300/5208 graphite/epoxy composite with a 0.6 fiber volume fraction. The mode transition occurs at 51.85° wave vector orientation with respect to the fiber direction. Energy flux deviation and particle displacement directions and amplitudes were also compared with theory. To show this mode transition, an attenuation study was performed. The attenuation coefficient, measured in units of reciprocal time, does not appear to depend on the wave vector orientation and the wave type (quasi-transverse and quasi-longitudinal waves) at 5 MHz frequency. 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