On fracture in finite strain gradient plasticity
File(s)
Accepted version
Author(s)
Martinez-Paneda, E
Niordson, CF
Type
Journal Article
Abstract
In this work a general framework for damage and fracture assessment including the effect of strain gradients is provided. Both mechanism-based and phenomenological strain gradient plasticity (SGP) theories are implemented numerically using finite deformation theory and crack tip fields are investigated. Differences and similarities between the two approaches within continuum SGP modeling are highlighted and discussed. Local strain hardening promoted by geometrically necessary dislocations (GNDs) in the vicinity of the crack leads to much higher stresses, relative to classical plasticity predictions. These differences increase significantly when large strains are taken into account, as a consequence of the contribution of strain gradients to the work hardening of the material. The magnitude of stress elevation at the crack tip and the distance ahead of the crack where GNDs significantly alter the stress distributions are quantified. The SGP dominated zone extends over meaningful physical lengths that could embrace the critical distance of several damage mechanisms, being particularly relevant for hydrogen assisted cracking models. A major role of a certain length parameter is observed in the multiple parameter version of the phenomenological SGP theory. Since this also dominates the mechanics of indentation testing, results suggest that length parameters characteristic of mode I fracture should be inferred from nanoindentation.
Date Issued
2016-05-01
Date Acceptance
2015-09-19
Citation
International Journal of Plasticity, 2016, 80, pp.154-167
ISSN
0749-6419
Publisher
Elsevier
Start Page
154
End Page
167
Journal / Book Title
International Journal of Plasticity
Volume
80
Copyright Statement
Copyright © 2015 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000374797500009&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Technology
Engineering, Mechanical
Materials Science, Multidisciplinary
Mechanics
Engineering
Materials Science
Strain gradient plasticity
Fracture
Finite strain
Crack mechanics
Finite elements
ENVIRONMENT-ASSISTED CRACKING
SINGLE-CRYSTAL PLASTICITY
DEFORMATION ANALYSIS
CONVENTIONAL THEORY
TIP FIELD
MODEL
GROWTH
DISLOCATIONS
INDENTATION
FORMULATION
Publication Status
Published
Date Publish Online
2015-09-30