Strain gradient crystal plasticity: A continuum mechanics approach to modeling micro-structural evolution

Salim Abdallah El-Naaman, Kim Lau Nielsen, Christian Frithiof Niordson

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Abstract

In agreement with dislocation theory, recent experiments show, both quantitatively and qualitatively, how geometrically necessary dislocations (GNDs) distribute in dislocation wall and cell structures. Hence, GND density fields are highly localized with large gradients and discontinuities occurring between the cells. This behavior is not typical for strain gradient crystal plasticity models. The present study employs a higher order extension of conventional crystal plasticity theory in which the viscous slip rate is influenced by the gradients of GND densities through a back stress. A phenomenological back stress formulation is proposed, through which the effect of the GND gradient exponent can be studied. It is shown that this model can lead to more localized GND distributions.
Original languageEnglish
Title of host publicationPlastic Behavior of Conventional and Advanced Materials: Theory, Experiment, and Modeling : Proceedings of PLASTICITY ’15
EditorsAkhtar S. Khan
Number of pages3
PublisherNEAT Press
Publication date2015
ISBN (Print)978-0-9911654-8-3
Publication statusPublished - 2015
Event21st International Symposium on Plasticity and its Current Applications - Hilton Rose Hall Resort & Spa, Montego Bay, Jamaica
Duration: 4 Jan 20159 Jan 2015
Conference number: 21

Conference

Conference21st International Symposium on Plasticity and its Current Applications
Number21
LocationHilton Rose Hall Resort & Spa
CountryJamaica
CityMontego Bay
Period04/01/201509/01/2015

Cite this

El-Naaman, S. A., Nielsen, K. L., & Niordson, C. F. (2015). Strain gradient crystal plasticity: A continuum mechanics approach to modeling micro-structural evolution. In A. S. Khan (Ed.), Plastic Behavior of Conventional and Advanced Materials: Theory, Experiment, and Modeling: Proceedings of PLASTICITY ’15 NEAT Press.