Fracture in mechanism-based strain gradient plasticity

Citation
H. Jiang et al., Fracture in mechanism-based strain gradient plasticity, J MECH PHYS, 49(5), 2001, pp. 979-993
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
ISSN journal
0022-5096 → ACNP
Volume
49
Issue
5
Year of publication
2001
Pages
979 - 993
Database
ISI
SICI code
0022-5096(200105)49:5<979:FIMSGP>2.0.ZU;2-S
Abstract
In a remarkable series of experiments, Elssner, Kern and Ruehle (Scripta Me tall. Mater. 31 (1994) 1037) observed cleavage fracture in ductile material s, a phenomenon that cannot be explained by classical plasticity theories; In this paper we present a study of fracture by the theory of mechanism-bas ed strain gradient (MSG) plasticity (Gao et al., J. Mech. Phys. Solids 47 ( 1999b) 1239); Huang et al., J. Mech. Phys. Solids 48 (2000a) 99). It is est ablished that, at a distance much larger than the dislocation spacing such that continuum plasticity is applicable, the stress level in MSG plasticity is significantly higher than that in classical plasticity near the crack t ip. The numerical results also show that the crack tip stress singularity i n MSG plasticity is higher than that in the HRR field, and it exceeds or eq uals to the square-root singularity. This study provides a means to explain the observed cleavage fracture in ductile material. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.