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A micromechanical model of hardening, rate sensitivity and thermal softening in BCC single crystals

Stainier, L. and Cuitiño, A. M. and Ortiz, M. (2002) A micromechanical model of hardening, rate sensitivity and thermal softening in BCC single crystals. Journal of the Mechanics and Physics of Solids, 50 (7). pp. 1511-1545. ISSN 0022-5096.

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The present paper is concerned with the development of a micromechanical model of the hardening, rate-sensitivity and thermal softening of bcc crystals. In formulating the model, we specifically consider the following unit processes: double-kink formation and thermally activated motion of kinks; the close-range interactions between primary and forest dislocations, leading to the formation of jogs; the percolation motion of dislocations through a random array of forest dislocations introducing short-range obstacles of different strengths; dislocation multiplication due to breeding by double cross-slip; and dislocation pair annihilation. The model is found to capture salient features of the behavior of Ta crystals such as: the dependence of the initial yield point on temperature and strain rate; the presence of a marked stage I of easy glide, specially at low temperatures and high strain rates; the sharp onset of stage II hardening and its tendency to shift towards lower strains, and eventually disappear, as the temperature increases or the strain rate decreases; the parabolic stage II hardening at low strain rates or high temperatures; the stage II softening at high strain rates or low temperatures; the trend towards saturation at high strains; the temperature and strain-rate dependence of the saturation stress; and the orientation dependence of the hardening rate.

Item Type:Article
Related URLs:
URLURL TypeDescription
Stainier, L.0000-0001-6719-6616
Cuitiño, A. M.0000-0002-5180-9147
Ortiz, M.0000-0001-5877-4824
Additional Information:© 2002 Elsevier. Received 28 March 2001, Accepted 18 August 2001, Available online 19 October 2001. The support of the DOE through Caltech's ASCI Center for the Simulation of the Dynamic Response of Materials is gratefully acknowledged. LS also wishes to acknowledge support from the Belgian National Fund for Scientific Research (FNRS).
Funding AgencyGrant Number
Department of Energy (DOE)UNSPECIFIED
Fonds National de la Recherche Scientifique (FNRS)UNSPECIFIED
Subject Keywords:A. Dislocations; B. Constitutive behavior; B. Crystal plasticity; B. Finite strain
Issue or Number:7
Record Number:CaltechAUTHORS:20171208-155120960
Persistent URL:
Official Citation:L. Stainier, A.M. Cuitiño, M. Ortiz, A micromechanical model of hardening, rate sensitivity and thermal softening in BCC single crystals, In Journal of the Mechanics and Physics of Solids, Volume 50, Issue 7, 2002, Pages 1511-1545, ISSN 0022-5096, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:83769
Deposited By: Lydia Suarez
Deposited On:20 Dec 2017 23:12
Last Modified:23 Nov 2020 20:30

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