Constitutive Modeling of SMA in Constrained Recovery Mode

Shape memory alloys (SMA) can develop large stresses in the constrained recovery mode. Heating generates tension in the material, depending upon the cooling temperature some residual stress may remain after actuation. Brinson’s one dimensional phenomenological model can be used to predict the stress/temperature loading paths in constrained recovery; however the model shows some discrepancies with experimental data when the SMA is cooled at low temperatures. This paper examines this behavior and proposes a modification to the Brinson model that better represents constrained recovery at low temperatures.