Preprint has been published in a journal as an article
DOI of the published article https://doi.org/10.1016/j.ijmecsci.2024.109569
Preprint / Version 3

Modeling the interaction between instabilities and functional degradation in shape memory alloys

##article.authors##

  • Mohsen Rezaee Hajidehi Institute of Fundamental Technological Research, Polish Academy of Sciences (IPPT)
  • Maciej Ryś NOMATEN Centre of Excellence, National Center for Nuclear Research (NCBJ)

DOI:

https://doi.org/10.31224/3512

Keywords:

Phase transformation, Propagating Instabilities, Functional fatigue, Subloop deformation, Finite-element method

Abstract

Localization of the stress-induced martensitic phase transformation plays an important role in the fatigue behavior of shape memory alloys (SMAs). The phenomenon of return-point memory that is observed during the subloop deformation of a partially-transformed SMA is a clear manifestation of the interaction between localized phase transformation and degradation of the functional properties. The present study aims to demonstrate this structure–material interaction in the modeling of return-point memory. It seems that this crucial aspect has been overlooked in previous modeling studies. For this purpose, we developed a gradient-enhanced model of pseudoelasticity that incorporates the degradation of functional properties in its constitutive description. The model is employed to reproduce the hierarchical return-point memory in a pseudoelastic NiTi wire under isothermal uniaxial tension with nested subloops. Additionally, a detailed analysis is carried out for a NiTi strip with more complex transformation pattern. Our study highlights the subtle morphological changes of phase transformation under different loading scenarios and the resulting implications for return-point memory.

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Posted

2024-02-01 — Updated on 2024-07-24

Versions

Version justification

This is the Author Accepted Manuscript version.