PSI - Issue 33

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

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ScienceDirect

Procedia Structural Integrity 33 (2021) 1035–1041

IGF26 - 26th International Conference on Fracture and Structural Integrity Cycling model for a NiTi Shape Memory Alloy

V. Di Cocco 1  , C. Bellini 1 , F. Iacoviello 1 , L.P Mocanu1, F. Berto 2 , R. Panetta 3 1 Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via G. Di Biasio 43, 03043 Cassino, Italy 2 NTNU, Richard Birkelands vei 2b, 7491, Trondheim, Norway 3 AMEmgineering, Via Tofaro 42, 03043 Sora (FR), Italy Di Cocco 1 ll 1 1 ocanu , 2 3

Abstract

© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the IGF ExCo Shape memory alloys are more and more used in many fields of mechanics and medicine. The reason of the success is the ability to recover the initial shape also after high values of deformation. During the deformation, the SMA are able to change the structure from an initial structure, often named as austenite, to a final structure named martensite. Neither austenite and martensite are the same of the equivalent structures of iron alloy, bit it is only a convention. That transformation takes place a low temperature, and no recrystallization occurs, but the bulk of grains is interested by the structure changing. For that, this phenomenon can’t be qualified as a traditional structure transformation, but it is much more correct talk about the transition of phase. The transition Austenite-Martensite is reversible allowing a perfect recover of the shape shown in the austenite phase. In this work a model able to describe the microstructure evolution related to the mechanical behaviour of a SMA has been proposed. Results of FEM simulations have been compared with experimental results both in terms of microstructure modifications and in terms of mechanical behaviour © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo Keywords: Shape Memory Alloy; Cycling; Phases transitions. e

 Corresponding author. E-mail address: v.dicocco@unicas.it

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review Statement: Peer-review under responsibility of the scientific committee of the IGF ExCo

2452-3216 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the IGF ExCo 10.1016/j.prostr.2021.10.115