Abstract
Multiaxial whole-life transformation ratchetting and fatigue failure of superelastic NiTi SMA micro-tubes are observed in the non-proportionally multiaxial stress-controlled cyclic tests at the human-body temperature (310K) under five different multiaxial loading paths. The effects of the axial peak stress and stress amplitude on the transformation ratchetting and fatigue life are addressed. It is found that the super-elastic NiTi SMA micro-tubes sustain more significant path-dependent fatigue failure in the multiaxial cyclic tests with lower axial peak stress and stress amplitude, while the fatigue lives of the NiTi micro-tubes under different loading paths are gradually converged with the increasing axial peak stress and stress amplitude. Based on the experimental findings, a fatigue failure model is proposed to predict the multiaxial fatigue life of the super-elastic NiTi SMA micro-tubes by considering the initial/saturated dissipation energy and the non-proportionality of the loading paths. It is shown that the predicted multiaxial fatigue lives agree with the experimental ones fairly well.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
