Cavitation in brittle metallic glasses - Effects of stress state and distributed weak zones

Singh, I and Guo, TF and Narasimhan, R and Zhang, YW (2014) Cavitation in brittle metallic glasses - Effects of stress state and distributed weak zones. In: INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, 51 (25-26). pp. 4373-4385.

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Abstract

Experimental studies and atomistic simulations have shown that brittle metallic glasses fail by a cavitation mechanism whose origin has been traced to the presence of intrinsic atomic density fluctuations which give rise to weak zones with reduced yield strength. It has been shown recently through continuum analysis that the presence of these zones can lower the cavitation stress considerably under equibiaxial loading. The objective of the present work is to study the effect of the applied stress state on the cavitation behavior of such a heterogeneous plastic solid with distributed weak zones. To this end, 2D plane strain finite element simulations are performed by subjecting a unit cell containing a weak zone to different (biaxiality) stress ratios. The volume fraction and yield strength of the weak zone are varied over a wide range. The results show that unlike in a homogeneous plastic solid, the cavitation stress of the heterogeneous aggregate does not reduce appreciably as the stress ratio decreases from unity when the yield strength of the weak zone is low. It is found that a non-dimensional parameter characterizing the stress state prevailing in the weak zone and its yield properties uniquely control the cavitation stress. The nature of cavitation bifurcation may change from unstable bifurcation to the left at sufficiently low stress ratio to one involving snap cavitation at high stress ratio. (C) 2014 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copyright for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Cavitation; Heterogeneous plastic solids; Stress state; Brittle metallic glass; Finite element analysis
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	12 Jan 2015 04:56
Last Modified:	12 Jan 2015 04:56
URI:	http://eprints.iisc.ac.in/id/eprint/50564

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