dc.contributor.author Kalpundi, Ganesh R. en_US dc.date.accessioned 2014-03-14T21:39:16Z dc.date.available 2014-03-14T21:39:16Z dc.date.issued 1993-08-05 en_US dc.identifier.other etd-06302009-040252 en_US dc.identifier.uri http://hdl.handle.net/10919/43480 dc.description.abstract A nonlinear mixed finite element formulation based on the Hellinger-Reissner variational principle is developed for planar contact stress analysis. The formulation is based on the updated Lagrangian approach and accounts for geometric nonlinearity. In the mixed model, both displacements and stresses are approximated independently and this approach has in general been found to be more accurate than the displacement finite element model, especially for contact problems since it avoids the extrapolation of stresses computed at the Gauss points to the boundary nodes. An algorithm based on the penalty technique for equality constraints has been developed to handle the interface boundary conditions arising in a contact problem. The algorithm automatically tracks potential contact nodes, detects overlap during any load step and iteratively restores geometric compatibility at the contact surface. The classical Hertz contact problem is solved to validate the algorithm. The mixed formulation algorithm in cylindrical coordinates is applied in conjunction with the penalty based algorithm to solve the contact problem in layered cylindrical bodies. Static condensation techniques are used to condense out the discontinuous components of stresses at the element level. The contact stress distribution and variation of contact area with load is computed for different loading situations. Furthermore, the effect of the difference in the relative magnitudes of the moduli of the layers on the stability of the contact algorithm is investigated. en_US dc.format.medium BTD en_US dc.publisher Virginia Tech en_US dc.relation.haspart LD5655.V855_1993.K356.pdf en_US dc.subject Constraints (Physics) en_US dc.subject.lcc LD5655.V855 1993.K356 en_US dc.title Nonlinear mixed finite element analysis for contact problems by a penalty constraint technique en_US dc.type Thesis en_US dc.contributor.department Engineering Mechanics en_US dc.description.degree Master of Science en_US thesis.degree.name Master of Science en_US thesis.degree.level masters en_US thesis.degree.grantor Virginia Polytechnic Institute and State University en_US thesis.degree.discipline Engineering Mechanics en_US dc.contributor.committeechair Thangjitham, Surot en_US dc.contributor.committeemember Heller, Robert A. en_US dc.contributor.committeemember Kapania, Rakesh K. en_US dc.identifier.sourceurl http://scholar.lib.vt.edu/theses/available/etd-06302009-040252/ en_US dc.date.sdate 2009-06-30 en_US dc.date.rdate 2009-06-30 dc.date.adate 2009-06-30 en_US
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