An experimental investigation on the interaction effect of cyclic loading parameters on the mechanical behavior of superelastic NiTi

Shape memory alloys (SMAs) are ideal for passive vibration control systems due to their energy dissipation capability under cyclic loading and exceptional superelasticity. Existing studies show that the mechanical properties of SMAs can vary significantly depending on the cyclic loading conditions. There is a complex interaction between the combined effect of cyclic loading parameters and internal variables that primarily governs the mechanical behavior of SMAs. While the effects of individual cyclic loading parameters on the mechanical behavior of SMAs have been widely studied, the interaction of these factors remains largely underexplored in the existing literature. The current study systematically explores the interaction of loading frequency, pre-strain, and strain amplitude on the mechanical response of superelastic NiTi, particularly in terms of energy dissipation, residual strain, and effective stiffness through an experimental approach that considers two of the parameters simultaneously. Moreover, theoretical rationalization for the observed SMA wire mechanical behavior resulted from complex interactions of different loading parameters have been offered, a dimension largely omitted in existing studies. This not only explains the inconsistent observations reported in literature, but also provides a predictive perception for SMA behavior beyond the tested parameter ranges.