A phenomenological model for superelasticity in NiTi alloys

摘要

A phenomenological model to simulate the superelastic effect in nickel-titanium (NiTi) alloys is proposed. The model is able to simulate the stress-strain hysteretic behaviour of the material in a phenomenological way by using the Prandtl-Ishlinskii operator. The parameters of the phenomenological model are identified by simple and efficient numerical procedures, from a set of experimental measurements. The model was developed in the commercial software package Simulink and is able to simulate complete and incomplete stress-induced martensitic transformations, as well as the effects of temperature on the stress-strain hysteretic behaviour. Systematic comparisons between experimental measurements, carried out for several stress paths, and numerical predictions are presented. The results show good accuracy and the model needs little computational time, which allows its use in real-time applications.