Thermoplastic composite consolidation

dc.contributor.authorLi, Min-Chungen
dc.contributor.committeechairLoos, Alfred C.en
dc.contributor.committeememberBaird, Donald G.en
dc.contributor.committeememberDillard, David A.en
dc.contributor.committeememberKander, Ronald G.en
dc.contributor.committeememberMorton, Johnen
dc.contributor.departmentMaterials Engineering Scienceen
dc.date.accessioned2014-03-14T21:21:50Zen
dc.date.adate2005-10-20en
dc.date.available2014-03-14T21:21:50Zen
dc.date.issued1993-10-05en
dc.date.rdate2005-10-20en
dc.date.sdate2005-10-20en
dc.description.abstractFabrication of high-quality composites from thennoplastic prepregs requires careful selection of the processing cycles so that intimate contact at the ply interfaces is achieved resulting in the formation of strong interply bonds and the process-induced residual stress is minimized to ensure superior mechanical performance. The void formation and the consolidation mechanism were studied experimentally. A refined model was developed to relate the processing parameters of pressure, temperature and time to the interply intimate contact of thermoplastic composites. The model was developed by integrating a prepreg surface topology characterization with a resin flow analysis. Both unidirectional and cross-ply lay-ups were modeled. Two-ply unidirectional laminae fabricated from graphite-polysulfone and graphite-PEEK prepregs and [0/90/0]<sub>T</sub> laminates were consolidated using different processing cycles. Optical microscopy and scanning acoustic microscopy were used to obtain the degree of intimate contact data. Agreement between the measured and calculated degree of intimate contact was good. A finite element model was developed to analyze residual stresses in thermoplastic composites by combining a plane-strain elasticity analysis and a temperature-dependent matrix properties. The residual stress model takes into account the mismatch of the thermal expansion coefficients and the crystallization shrinkage of the matrix. [O₁₀/90₆]<sub>T</sub> graphite-PEEK laminates were manufactured at different cooling rates to verify the model. The induced residual thermal defonnations were measured by a shadow moire system. The model accurately estimated the out-of-plane displacement of the non-symmetrical laminates.en
dc.description.degreePh. D.en
dc.format.extentxiii, 191 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-10202005-102827en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10202005-102827/en
dc.identifier.urihttp://hdl.handle.net/10919/40036en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V856_1993.L497.pdfen
dc.relation.isformatofOCLC# 29985324en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1993.L497en
dc.subject.lcshThermoplastic compositesen
dc.titleThermoplastic composite consolidationen
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineMaterials Engineering Scienceen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
LD5655.V856_1993.L497.pdf
Size:
40.8 MB
Format:
Adobe Portable Document Format