A numerical study of the indentation mechanics of shape memory alloys in different temperature regimes

Anuja, J and Narasimhan, R and Ramamurty, U (2019) A numerical study of the indentation mechanics of shape memory alloys in different temperature regimes. In: MECHANICS OF MATERIALS, 139 .

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Abstract

Instrumented indentation is a versatile technique to quantify not only the mechanical properties but also the phase transformation and recovery characteristics of shape memory alloys (SMAs). The objective of this work is to investigate the effect of temperature on the mechanics of spherical indentation of SMAs as manifested through stress induced martensite transformation (SIMT) and plastic yielding. To this end, finite element simulations of spherical indentation response of Ni-Ti based SMAs are carried out using a constitutive model that incorporates the combined effects of superelasticity and plasticity. A range of temperatures from well below to above the austenite finish temperature A(f) is considered. It is found that while SIMT is the governing deformation mode during indentation at temperatures below A(f), plastic yielding becomes significant at temperatures close to and above A(f). The load and mean contact pressure increase with temperature above A(f) at a given indentation depth. Also, the remnant depth ratio for a given load is lowest close to A(f). SIMT and plastic deformation influence the stress distribution differently depending on the temperature.

Item Type:	Journal Article
Publication:	MECHANICS OF MATERIALS
Publisher:	ELSEVIER
Additional Information:	Copyright for this article belongs to Elsevier.
Keywords:	Indentation mechanics; Shape memory alloys; Temperature effect; Numerical investigation; Superelasticity
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	13 Jan 2020 07:59
Last Modified:	13 Jan 2020 07:59
URI:	http://eprints.iisc.ac.in/id/eprint/64093

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