A strain gradient plasticity theory with application to wire torsion

Handle URI:
http://hdl.handle.net/10754/594095
Title:
A strain gradient plasticity theory with application to wire torsion
Authors:
Liu, J. X.; El Sayed, Tamer S.
Abstract:
Based on the framework of the existing strain gradient plasticity theories, we have examined three kinds of relations for the plastic strain dependence of the material intrinsic length scale, and thus developed updated strain gradient plasticity versions with deformation-dependent characteristic length scales. Wire torsion test is taken as an example to assess existing and newly built constitutive equations. For torsion tests, with increasing plastic strain, a constant intrinsic length predicts too high a torque, while a decreasing intrinsic length scale can produce better predictions instead of the increasing one, different from some published observations. If the Taylor dislocation rule is written in the Nix-Gao form, the derived constitutive equations become singular when the hardening exponent gets close to zero, which seems questionable and calls for further experimental clarifications on the exact coupling of hardening due to statistically stored dislocations and geometrically necessary dislocations. Particularly, when comparing the present model with the mechanism-based strain gradient plasticity, the present model satisfies the reciprocity relation naturally and gives different predictions even under the same parameter setting. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division; Physical Sciences and Engineering (PSE) Division
Citation:
Liu J, ElSayed T (2014) A strain gradient plasticity theory with application to wire torsion. International Journal of Damage Mechanics 24: 512–528. Available: http://dx.doi.org/10.1177/1056789514537920.
Publisher:
SAGE Publications
Journal:
International Journal of Damage Mechanics
Issue Date:
5-Jun-2014
DOI:
10.1177/1056789514537920
Type:
Article
ISSN:
1056-7895; 1530-7921
Sponsors:
The work of J.X. Liu was supported by the Jiangsu University and Jiangsu Specially-Appointed Professor grants, as well as by the KAUST baseline fund.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorLiu, J. X.en
dc.contributor.authorEl Sayed, Tamer S.en
dc.date.accessioned2016-01-19T13:21:31Zen
dc.date.available2016-01-19T13:21:31Zen
dc.date.issued2014-06-05en
dc.identifier.citationLiu J, ElSayed T (2014) A strain gradient plasticity theory with application to wire torsion. International Journal of Damage Mechanics 24: 512–528. Available: http://dx.doi.org/10.1177/1056789514537920.en
dc.identifier.issn1056-7895en
dc.identifier.issn1530-7921en
dc.identifier.doi10.1177/1056789514537920en
dc.identifier.urihttp://hdl.handle.net/10754/594095en
dc.description.abstractBased on the framework of the existing strain gradient plasticity theories, we have examined three kinds of relations for the plastic strain dependence of the material intrinsic length scale, and thus developed updated strain gradient plasticity versions with deformation-dependent characteristic length scales. Wire torsion test is taken as an example to assess existing and newly built constitutive equations. For torsion tests, with increasing plastic strain, a constant intrinsic length predicts too high a torque, while a decreasing intrinsic length scale can produce better predictions instead of the increasing one, different from some published observations. If the Taylor dislocation rule is written in the Nix-Gao form, the derived constitutive equations become singular when the hardening exponent gets close to zero, which seems questionable and calls for further experimental clarifications on the exact coupling of hardening due to statistically stored dislocations and geometrically necessary dislocations. Particularly, when comparing the present model with the mechanism-based strain gradient plasticity, the present model satisfies the reciprocity relation naturally and gives different predictions even under the same parameter setting. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.en
dc.description.sponsorshipThe work of J.X. Liu was supported by the Jiangsu University and Jiangsu Specially-Appointed Professor grants, as well as by the KAUST baseline fund.en
dc.publisherSAGE Publicationsen
dc.subjectgeometrically necessary dislocationen
dc.subjectlength scale effecten
dc.subjectstrain dependenceen
dc.subjectStrain gradient plasticityen
dc.subjectTaylor dislocation relationen
dc.subjecttorsionen
dc.titleA strain gradient plasticity theory with application to wire torsionen
dc.typeArticleen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalInternational Journal of Damage Mechanicsen
dc.contributor.institutionFaculty of Civil Engineering and Mechanics, Jiangsu University, 301 Xuefu RoadZhenjiang, Jiangsu, Chinaen
kaust.authorEl Sayed, Tamer S.en
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