Modeling of the size effect in the plastic behavior of polycrystalline materials

dc.contributor.advisor Johnson, W. Steven
dc.contributor.advisor Cherkaoui, Mohammed
dc.contributor.advisor Qu, Jianmin
dc.contributor.author Capolungo, Laurent en_US
dc.contributor.committeeMember Garmestani, Hamid
dc.contributor.committeeMember McDowell, David
dc.contributor.department Mechanical Engineering en_US
dc.date.accessioned 2007-08-16T17:57:35Z
dc.date.available 2007-08-16T17:57:35Z
dc.date.issued 2007-06-11 en_US
dc.description.abstract This thesis focuses on the study of the size effect in the elastic-viscoplastic response of pure face centered cubic polycrystalline materials. First, the effect of vacancy diffusion is studied via the use of a two-phase self-consistent scheme in which the inclusion phase represents grain interiors and the matrix phase represents grain boundaries. The behavior of the inclusion phase is driven by the activity of dislocations, described with typical strain hardening laws, and by the activity of Coble creep. The behavior of the matrix phase is modeled as elastic-perfect plastic. This model is then extended to account for the possible activity of Lifschitz sliding. The active role of grain boundaries to the viscoplastic deformation is studied with the introduction of a novel method allowing the scale transition from the atomistic scale to the macroscopic scale. A model describing the mechanism of grain boundary dislocation emission and penetration is informed with molecular simulations and finite element simulations. The macroscopic response of the material is then predicted with use of several self-consistent schemes, among which two novel three-phases schemes are introduced. The most refined micromechanical scheme proposed is based on a two-phase representation of the material and is valid in the elastic-viscoplastic regime and accounts for the effect of slightly weakened interfaces. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/16276
dc.publisher Georgia Institute of Technology en_US
dc.subject Dislocations en_US
dc.subject Grain boundary en_US
dc.subject Micromechanics en_US
dc.subject Nanocrystalline en_US
dc.title Modeling of the size effect in the plastic behavior of polycrystalline materials en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Johnson, W. Steven
local.contributor.corporatename George W. Woodruff School of Mechanical Engineering
local.contributor.corporatename College of Engineering
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relation.isOrgUnitOfPublication c01ff908-c25f-439b-bf10-a074ed886bb7
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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