Journal
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
Volume 33, Issue 14, Pages 1834-1845Publisher
SAGE PUBLICATIONS LTD
DOI: 10.1177/1045389X211072233
Keywords
NiTi SMAs; thermomechanical cycling; phase transformation; fatigue; upper cycle temperature
Categories
Funding
- Scientific and Engineering Research Board, Department of Science and Technology, India [CRG/2019/002267]
Ask authors/readers for more resources
This study investigates the influence of upper cycle temperature and applied stress on the functional properties of an SMA during partial thermomechanical cycling. The results show that decreasing the upper cycle temperature and stress level can improve the stability and lifespan of SMAs.
In this study, the influence of upper cycle temperature (maximum temperature in a cycle) and the magnitude of applied stress on the functional properties of an SMA during partial thermomechanical cycling has been studied. A near-equiatomic NiTi SMA was chosen and tested under different upper cycle temperatures (between martensite finish (M-f) and austenite finish (A(f)) temperatures) and stress level (below and above the yield strength of the martensite). The upper cycle temperature was varied by controlling the magnitude of the current supply. The results show that a raise in the upper cycle temperature causes the permanent strain to increase and also lowers the stability. However, decreasing the stress imposed to a value lower than the yield strength of the martensite improves cyclic stability. The upper cycle temperature was found to influence the crack nucleation, whereas the applied stress level the crack propagation during partial thermomechanical cycling of SMAs. Therefore, decreasing the upper cycle temperature as well as the magnitude of stress applied to lower than the yield stress of martensite have been found to be suitable strategies for increasing the lifespan of SMA-based actuators during partial thermomechanical cycling.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available