ARTICLE
Modeling of dynamic growth of a micro-scaled void based on strain gradient elasto-plasticity
| 1 | Jiangsu University, Faculty of Civil Engineering and Mechanics, Zhenjiang, Jiangsu Province, China |
| 2 | Wuhan University of Science and Technology, The State Key Laboratory of Refractories and Metallurgy, Wuhan, Hubei
Province |
| 3 | Institute of Applied Physics and Computational Mathematics, Beijing, China |
CORRESPONDING AUTHOR
Submission date: 2019-10-21
Final revision date: 2020-02-11
Acceptance date: 2020-02-25
Online publication date: 2020-10-15
Publication date: 2020-10-15
Journal of Theoretical and Applied Mechanics 2020;58(4):927–941
KEYWORDS
TOPICS
ABSTRACT
Void initiation and growth serve as an important mechanism in ductile failures in metals.
Particularly, on the micron-level, the extra hardening effect associated with strain gradient
is accounted for by adopting strain gradient elasto-plasticity instead of the conventional
plasticity. Effects of inertial, strain gradient hardening and thermal softening are formulated
analytically for the case where a spherical void expands under external hydrostatic stress.
As demonstrated by our results, the inertia effect firstly tends to hinder but then promotes
the void growth. The threshold stress required for rapid void growth is lifted due to extra
hardening of strain gradient so that the growth of a smaller void is delayed more remarkably.
A considerable thermal softening phenomenon is observed here, which is caused by plastic
work during the deformation process. The final void growth rate is mainly related to the
maximum loading, which is consistent with the prediction based on the classical plastic
theory.
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