A variational multiscale constitutive model for nanocrystalline materials
Type
ArticleAuthors
Gurses, ErcanEl Sayed, Tamer S.
KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionPhysical Science and Engineering (PSE) Division
Date
2011-03Permanent link to this record
http://hdl.handle.net/10754/561720
Metadata
Show full item recordAbstract
This paper presents a variational multi-scale constitutive model in the finite deformation regime capable of capturing the mechanical behavior of nanocrystalline (nc) fcc metals. The nc-material is modeled as a two-phase material consisting of a grain interior phase and a grain boundary effected zone (GBAZ). A rate-independent isotropic porous plasticity model is employed to describe the GBAZ, whereas a crystal-plasticity model which accounts for the transition from partial dislocation to full dislocation mediated plasticity is employed for the grain interior. The constitutive models of both phases are formulated in a small strain framework and extended to finite deformation by use of logarithmic and exponential mappings. Assuming the rule of mixtures, the overall behavior of a given grain is obtained via volume averaging. The scale transition from a single grain to a polycrystal is achieved by Taylor-type homogenization where a log-normal grain size distribution is assumed. It is shown that the proposed model is able to capture the inverse HallPetch effect, i.e., loss of strength with grain size refinement. Finally, the predictive capability of the model is validated against experimental results on nanocrystalline copper and nickel. © 2010 Elsevier Ltd. All rights reserved.Citation
Gürses, E., & El Sayed, T. (2011). A variational multiscale constitutive model for nanocrystalline materials. Journal of the Mechanics and Physics of Solids, 59(3), 732–749. doi:10.1016/j.jmps.2010.10.010Sponsors
The authors are grateful to the very relevant suggestions made by the reviewers. The authors would like to thank the KAUST Research Computing team for their technical support. This work was fully funded by the KAUST baseline fund.Publisher
Elsevier BVae974a485f413a2113503eed53cd6c53
10.1016/j.jmps.2010.10.010