Puri2009p7074J_Mech_Mater_Struct.pdf (952.06 kB)

Modeling dislocation sources and size effects at initial yield in continuum plasticity

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journal contribution
posted on 17.06.2014, 13:14 by Saurabh Puri, Anish Roy, Amit Acharya, Dennis Dimiduk
Size effects at initial yield (prior to stage II) of idealized micron-sized specimens are modeled within a continuum model of plasticity. Two different aspects are considered: specification of a density of dislocation sources that represent the emission of dislocation dipoles, and the presence of an initial, spatially inhomogeneous excess dislocation content. Discreteness of the source distribution appears to lead to a stochastic response in stress-strain curves, with the stochasticity diminishing as the number of sources increases. Variability in stress-strain response due to variations of source distribution is also shown. These size effects at initial yield are inferred to be due to physical length scales in dislocation mobility and the discrete description of sources that induce internal-stress-related effects, and not due to length-scale effects in the mean-field strain-hardening response (as represented through a constitutive equation).

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

JOURNAL OF MECHANICS OF MATERIALS AND STRUCTURES

Volume

4

Issue

9

Pages

1603 - 1618 (16)

Citation

PURI, S. ... et al, 2009. Modeling dislocation sources and size effects at initial yield in continuum plasticity. Journal of Mechanics of Materials and Structures, 4 (9), pp. 1603 - 1618.

Publisher

Mathematical Sciences Publishers

Version

VoR (Version of Record)

Publication date

2009

Notes

First published in Journal of Mechanics of Materials and Structures in 2009 vol 4 pt. 9, published by Mathematical Sciences Publishers.

ISSN

1559-3959

Language

en

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