Analysis by Meshless Local Petrov-Galerkin Method of Material Discontinuities, Pull-in Instability in MEMS, Vibrations of Cracked Beams, and Finite Deformations of Rubberlike Materials

dc.contributor.authorPorfiri, Maurizioen
dc.contributor.committeechairBatra, Romesh C.en
dc.contributor.committeememberLindner, Douglas K.en
dc.contributor.committeememberLibrescu, Liviuen
dc.contributor.committeememberHyer, Michael W.en
dc.contributor.committeememberHenneke, Edmund G. IIen
dc.contributor.departmentEngineering Science and Mechanicsen
dc.date.accessioned2014-03-14T20:11:12Zen
dc.date.adate2006-05-08en
dc.date.available2014-03-14T20:11:12Zen
dc.date.issued2006-04-27en
dc.date.rdate2006-05-08en
dc.date.sdate2006-04-28en
dc.description.abstractThe Meshless Local Petrov-Galerkin (MLPG) method has been employed to analyze the following linear and nonlinear solid mechanics problems: free and forced vibrations of a segmented bar and a cracked beam, pull-in instability of an electrostatically actuated microbeam, and plane strain deformations of incompressible hyperelastic materials. The Moving Least Squares (MLS) approximation is used to generate basis functions for the trial solution, and for the test functions. Local symmetric weak formulations are derived, and the displacement boundary conditions are enforced by the method of Lagrange multipliers. Three different techniques are employed to enforce continuity conditions at the material interfaces: Lagrange multipliers, jump functions, and MLS basis functions with discontinuous derivatives. For the electromechanical problem, the pull-in voltage and the corresponding deflection are extracted by combining the MLPG method with the displacement iteration pull-in extraction algorithm. The analysis of large deformations of incompressible hyperelastic materials is performed by using a mixed pressure-displacement formulation. For every problem studied, computed results are found to compare well with those obtained either analytically or by the Finite Element Method (FEM). For the same accuracy, the MLPG method requires fewer nodes but more CPU time than the FEM.en
dc.description.degreePh. D.en
dc.identifier.otheretd-04282006-102241en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04282006-102241/en
dc.identifier.urihttp://hdl.handle.net/10919/27420en
dc.publisherVirginia Techen
dc.relation.haspartporfiri_etd.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectRubberlike Materialsen
dc.subjectDiscontinuitiesen
dc.subjectVibrationsen
dc.subjectMEMSen
dc.subjectMLPG methoden
dc.titleAnalysis by Meshless Local Petrov-Galerkin Method of Material Discontinuities, Pull-in Instability in MEMS, Vibrations of Cracked Beams, and Finite Deformations of Rubberlike Materialsen
dc.typeDissertationen
thesis.degree.disciplineEngineering Science and Mechanicsen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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