Plasticity size effects in tension and compression of single crystals

VS Deshpande*, A Needleman, E Van der Giessen

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

150 Citaten (Scopus)
342 Downloads (Pure)

Samenvatting

The effect of size and loading conditions on the tension and compression stress-strain response of micron-sized planar crystals is investigated using discrete dislocation plasticity. The crystals are taken to have a single active slip system and both small-strain and finite-strain analyses are carried out. When rotation of the tensile axis is constrained, the build-up of geometrically necessary dislocations results in a weak size dependence but a strong Bauschinger effect. On the other hand, when rotation of the tensile axis is unconstrained, there is a strong size dependence, with the flow strength increasing with decreasing specimen size, and a negligible Bauschinger effect. Below a certain specimen size, the flow strength of the crystals is set by the nucleation strength of the initially present Frank-Read sources. The main features of the size dependence are the same for the small-strain and finite-strain analyses. However, the predicted hardening rates differ and the finite-strain analyses give rise to some tension-compression asymmetry. (c) 2005 Elsevier Ltd. All rights reserved.

Originele taal-2English
Pagina's (van-tot)2661-2691
Aantal pagina's31
TijdschriftJournal of the Mechanics and Physics of Solids
Volume53
Nummer van het tijdschrift12
DOI's
StatusPublished - dec.-2005

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