Effect of electric field on creep and stress-relaxation behavior of carbon nanotube forests

Jagtap, Piyush and Kumar, Amit and Kumar, Praveen (2016) Effect of electric field on creep and stress-relaxation behavior of carbon nanotube forests. In: RSC ADVANCES, 6 (72). pp. 67685-67692.

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Abstract

Carbon nanotube forests (CNTFs) are porous ensembles of vertically aligned carbon nanotubes, exhibiting excellent reversible compressibility and electric field tunable stress-strain response. Here, we report the effects of electric field on the time dependent mechanical behavior, namely creep and stress-relaxation, of CNTFs. Creep and stress-relaxation experiments were conducted under constant compressive stress and constant compressive strain, respectively, wherein variation of the strain and the stress, respectively, as functions of time were measured. Creep strain-time data of CNTFs showed a primary creep regime followed by a steady-state creep regime. The creep rate was substantially retarded upon application of electric field. The steady-state strain rate showed a power-law dependence on the stress; however, the stress exponent reduced when an electric field was applied. On other hand, electric field enhanced stress-relaxation in CNTFs, leading to a lower value of stress at a given time. However, the effect of electric field on the stress-relaxation reduced with compressive strain. Based on the Garofalo model of creep, a unified model for explaining the overall time dependent mechanical behavior of CNTFs and the observed experimental results was developed.

Item Type:	Journal Article
Publication:	RSC ADVANCES
Additional Information:	Copy right for this article belongs to the ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	08 Oct 2016 05:43
Last Modified:	08 Oct 2016 05:43
URI:	http://eprints.iisc.ac.in/id/eprint/54717

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