Issue 50

V. Iasnii et alii, Frattura ed Integrità Strutturale, 50 (2019) 310-318; DOI: 10.3221/IGF-ESIS.50.26 310 The effect of temperature on low-cycle fatigue of shape memory alloy V. Iasnii, P. Yasniy, D. Baran Faculty of Engineering of Machines, Structures and Technologies, Ternopil Ivan Puluj National Technical University, Ternopil, Ukraine v_iasnii@tntu.edu.ua , https://orcid.org/0000-0002-5768-5288 petroyasniy@gmail.com, https://orcid.org/0000-0002-1928-7035 jaturonkabat@gmail.com, https://orcid.org/0000-0002-2067-8164 A. Rudawska Faculty of Mechanical Engineering, Lublin University of Technology, Lublin, Poland a.rudawska@pollub.pl , https://orcid.org/0000-0003-3592-8047 A BSTRACT . The influence of temperature on the fatigue properties of pseudoelastic NiTi under low-cycle fatigue are investigated. Tests were performed under the uniaxial tensile deformation (pull-pull) at 0°С and 20°С which is above the austenite finish temperature. Experimental results indicate that the fatigue life of NiTi alloy increases with the decrease of test temperature from 20°С to 0°С in the case of presenting the results depending on the strain range and dissipated energy . Regardless the test temperature, with the increase of number of cycles to failure, the stress and strain ranges, as well as the dissipation energy decrease, and the total dissipation energy and Odqvist’s parameter increase. The slope of the fatigue curves of NiTi alloy is greater at the temperature of 0°С in comparison with the 20°С in the case of employing the stress range, strain range, Odqvist’s parameter, and total dissipation energy as the failure criteria, and is less while employing the dissipation energy as the failure criterion. K EYWORDS . Pseudoelsticity; NiTi alloy; Low-cycle fatigue; Odqvist’s parameter; Dissipated energy. Citation: Iasnii, V., Yasniy, P., Baran, D., Rudawska, A., The effect of temperature on low-cycle fatigue of shape memory alloy, Frattura ed Integrità Strutturale, 50 (2019) 310-318. Received: 26.07.2019 Accepted: 19.08.2019 Published: 01.10.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION nlike traditional structural materials, shape memory alloys (SMA) are characterized not only by mechanical and operational properties but also by functional ones. The functional properties of SMA include shape memory effect and the pseudoelasticity. Typical stress-strain curve of pseudoelastic SMAs above the austenite finish temperature shows a large hysteresis loop during loading and unloading. The hysteretic behaviour results in a high dissipation energy and stored strain energy which ensure high performance of SMA as a material for damping and storing the energy. U