Defect induced plasticity and failure mechanism of boron nitride nanotubes under tension

Krishnan, Anoop NM and Ghosh, Debraj (2014) Defect induced plasticity and failure mechanism of boron nitride nanotubes under tension. In: JOURNAL OF APPLIED PHYSICS, 116 (4).

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Abstract

The effects of Stone-Wales (SW) and vacancy defects on the failure behavior of boron nitride nanotubes (BNNTs) under tension are investigated using molecular dynamics simulations. The Tersoff-Brenner potential is used to model the atomic interaction and the temperature is maintained close to 300 K. The effect of a SW defect is studied by determining the failure strength and failure mechanism of nanotubes with different radii. In the case of a vacancy defect, the effect of an N-vacancy and a B-vacancy is studied separately. Nanotubes with different chiralities but similar diameter is considered first to evaluate the chirality dependence. The variation of failure strength with the radius is then studied by considering nanotubes of different diameters but same chirality. It is observed that the armchair BNNTs are extremely sensitive to defects, whereas the zigzag configurations are the least sensitive. In the case of pristine BNNTs, both armchair and zigzag nanotubes undergo brittle failure, whereas in the case of defective BNNTs, only the zigzag ones undergo brittle failure. An interesting defect induced plastic behavior is observed in defective armchair BNNTs. For this nanotube, the presence of a defect triggers mechanical relaxation by bond breaking along the closest zigzag helical path, with the defect as the nucleus. This mechanism results in a plastic failure. (C) 2014 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	JOURNAL OF APPLIED PHYSICS
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	18 Sep 2014 09:11
Last Modified:	18 Sep 2014 09:11
URI:	http://eprints.iisc.ac.in/id/eprint/49902

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