One-Dimensional Heat Source Reconstruction Applied to Phase Transforming Superelastic Ni-Ti Wire

0525135 - ÚJF 2021 RIV US eng C - Conference Paper (international conference)
Jury, Antoine - Balandraud, X. - Heller, Luděk - Alarcon, Eduardo - Karlík, M.
One-Dimensional Heat Source Reconstruction Applied to Phase Transforming Superelastic Ni-Ti Wire.
Conference Proceedings of the Society for Experimental Mechanics Series. Vol. 6. New York: Springer, 2020, s. 33-40. ISBN 978-3-030-30098-2.
[2019 SEM Annual Conference and Exposition on Experimental and Applied Mechanics. Reno (US), 03.06.2019-09.06.2019]
R&D Projects: GA MŠMT EF16_013/0001794
Institutional support: RVO:61389005
Keywords : heat source reconstruction * infrared thermography * NiTi * shape-memory alloy * superelasticity
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
https://doi.org/10.1007/978-3-030-30098-2_6

The study deals with the reconstruction of heat sources originating from deformation processes in metals. A one-dimensional method to be applied on wires or bars is introduced and tested on superelastic NiTi wire subjected to force-controlled loading and unloading. Infrared thermography was used for this purpose. Thermal data were then processed by heat source reconstruction technique using a one-dimensional version of the heat diffusion equation. Attention was paid to the identification of the heat exchanges with the specimen’s environment, in particular by convection to the air of ambient temperature. The sensitivity of the method to the degree of spatio-temporal filtering was also tested. Finally, the localization of martensitic transformation in superelastic NiTi was evaluated using the proposed method. It is shown that under force-control regime the phase transformation proceeds in two time-shifted bursts, where each of bursts consists in several displaced and nearly simultaneous transforming zones. This transformation sequence is rationalized by fast latent heat release from the transforming zone upon load control regime, which leads to overheating of surrounding zones thus temporarily suppressing their transformation.
Permanent Link: http://hdl.handle.net/11104/0309341