Localized Plateau-Based Validation of Classical Phenomenological Models for Superelastic Shape Memory Alloys

The superelastic behavior of shape memory alloys (SMAs) arises from stress-induced martensitic transformation and plays an important role in the design of smart engineering systems, including aerospace components. Reliable constitutive modeling is therefore essential for accurately predicting their mechanical response in numerical simulations of SMA-based engineering systems. In this study, a localized plateau-based comparative evaluation framework is employed to compare the classical Brinson and Liang–Rogers phenomenological models using published experimental stress–strain data of superelastic NiTi alloys under isothermal tensile loading–unloading conditions at two different temperatures. Model performance is assessed using global RMSE, localized plateau RMSE, and hysteretic energy dissipation. The results show that both constitutive models provide close agreement with the overall superelastic hysteresis response and predict comparable hysteretic energy dissipation. However, the Liang–Rogers model consistently provides lower localized RMSE values within the forward and reverse transformation plateau regions. The principal contribution of this work is the introduction of a localized comparative evaluation framework that complements conventional global error measures for comparing phenomenological SMA constitutive models.