PSI - Issue 38

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 38 (2022) 546–553

© 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 Fatigue Design 2021 Organizers Abstract NiTi shape memory alloy is a kind of smart material which present unique properties of superelasticity, shape memory and excellent biocompatibility. The applications of such alloys are generally the connectors and fasteners, vibration-dampers, and endovascular stents, etc.. The cyclic deformation and fatigue failure of NiTi SMAs are key issues that need to be investigated since they usually endure complex cyclic loadings during the using process. In this paper, the evolutions of the peak/valley strains in non-proportional multiaxial fatigue loadings of NiTi SMAs are considered, and the fatigue failure mechanism is investigated. The results show that the martensite transformation and martensite re-orientation process greatly influence the transformation ratcheting and fatigue life of NiTi SMAs, and a life-prediction model that considers these deformation mechanisms particular for NiTi SMAs is also proposed to give reasonable predictions. © 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 Fatigue Design 2021 Organizers Keywords: NiTi shape memory alloys; fatigue failure; superelasticity; cyclic deformation. blished by This is an open access article under the CC BY-NC-ND license (https://creativecomm FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design The cyclic strain evolution and the fatigue prediction in non proportional multiaxial loadings of NiTi SMAs *Di Song a,b,c, *, Chao Yu d a School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi Tech Zone, 611731 Chengdu, P.R. China b Materials Mechanics Group, Department of Civil and Environmental Sciences, Technical University of Darmstadt, Franziska-Braun-Straße 3, 64285 Darmstadt, Germany c Institute of Electronic and Information Engineering of UESTC in Guangdong, No. 17, Headquarters 2nd Road, Songshan Lake High-tech Industrial Development Zone, 523808 Dongguan, P.R.China d School of Mechanics and Engineering, Southwest Jiaotong University, No. 111, North Section 1, Second Ring Road, 610031 Chengdu, P.R. China le

* Corresponding author. Tel.: +49 6151 16-23086; fax: +49 6151 16-23083. E-mail address: song@wm.tu-darmstadt.de; songdi@uestc.edu.cn

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 Fatigue Design 2021 Organizers d by

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 Fatigue Design 2021 Organizers 10.1016/j.prostr.2022.03.055