A strain gradient plasticity theory with application to wire torsion
Type
ArticleAuthors
Liu, J. X.El Sayed, Tamer S.
KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionPhysical Science and Engineering (PSE) Division
Date
2014-06-05Online Publication Date
2014-06-05Print Publication Date
2015-05Permanent link to this record
http://hdl.handle.net/10754/594095
Metadata
Show full item recordAbstract
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.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.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.Publisher
SAGE Publicationsae974a485f413a2113503eed53cd6c53
10.1177/1056789514537920