Combined Compression and Shear Structural Evaluation of Stiffened Panels Fabricated Using Electron Beam Freeform Fabrication

dc.contributor.authorNelson, Erik Walteren
dc.contributor.committeechairKapania, Rakesh K.en
dc.contributor.committeememberPhilen, Michael K.en
dc.contributor.committeememberHyer, Michael W.en
dc.contributor.committeememberTaminger, Karen M.en
dc.contributor.departmentAerospace and Ocean Engineeringen
dc.date.accessioned2014-03-14T21:39:44Zen
dc.date.adate2008-07-30en
dc.date.available2014-03-14T21:39:44Zen
dc.date.issued2008-06-17en
dc.date.rdate2008-07-30en
dc.date.sdate2008-07-08en
dc.description.abstractUnitized aircraft structures have the potential to be more efficient than current aircraft structures. The Electron Beam Freeform Fabrication (EBF3) process can be used to manufacture unitized aircraft structures. The structural efficiency of blade stiffened panels made with EBF3 was compared to panels made by integrally machining from thick plate. The panels were tested under two load cases in a combined compression-shear load test fixture. One load case tested the panels' responses to a higher compressive load than the shear load. The second load case tested the panels' responses to an equal compressive and shear load. Finite element analysis was performed to compare with the experimental results. The EBF3 panels failed at a 18.5% lower buckling load than the machined panels when loaded mostly in compression but at an almost two times higher buckling load than the machined panels when the shear matched the compressive load. The finite element analysis was in good agreement with the experimental results prior to buckling. The results demonstrate that the EBF3 process has the capabilities of manufacturing stiffened panels that behave similarly to machined panels prior to buckling. Once the EBF3 panels buckled, the buckled shape of the EBF3 panels was different from the machined panels, generally buckling in the opposite direction of what was observed with the machined panels. This was also expected based on the finite element analysis. The different post-buckling response between the two manufacturing techniques was attributed to the residual stress and associated distortion induced during the EBF3 manufacturing process.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-07082008-145820en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07082008-145820/en
dc.identifier.urihttp://hdl.handle.net/10919/43583en
dc.publisherVirginia Techen
dc.relation.haspartVT_Final_Thesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectstiffeneren
dc.subjectbucklingen
dc.subjectstiffened panelsen
dc.subjectshearen
dc.subjectcompressionen
dc.subjectFinite element methoden
dc.subjectElectron Beam Freeform Fabricationen
dc.titleCombined Compression and Shear Structural Evaluation of Stiffened Panels Fabricated Using Electron Beam Freeform Fabricationen
dc.typeThesisen
thesis.degree.disciplineAerospace and Ocean Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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