Improvement and experimental research on the recovery stress-temperature model of NiTi shape memory alloys

To eliminate the prediction errors of the recovery stress model of NiTi SMAs caused by the incomplete reverse martensitic transformation, an improved prediction model of recovery stress was developed based on the one-dimensional constitutive behavior model proposed by Brinson for shape memory alloys (SMAs). This model regarded the martensitic recovery factor as an internal variable and took the stress and temperature into account as influencing factors to martensitic content of SMAs. The curve of recovery stress of NiTi SMAs with different initial strains versus temperature was measured by experiments. Compared with the experimental results, the computation result shows that the model has certain accuracy in calculating the recovery stress-temperature curve.