Stress-dependent calibration of a thermoelastic constitutive model for Cu-Zn-Al shape memory alloys

Shape memory alloys (SMAs) have gained significant attention for their unique thermomechanical properties. This paper presents a phenomenological model for the thermoelastic strain–temperature response of Cu-Zn-Al SMAs. The constitutive equations are derived from thermodynamics, and parameters are calibrated at two constant stresses (65 and 100 MPa) using data for the same alloy from the literature. The simulations reproduce, after calibration, the transformation-strain amplitude and the hysteresis width at each stress. A key observation is that fitted parameters vary with the applied stress, which highlights the model’s descriptive capability under specified loading and its limitations as a predictive tool without additional functionalization and data.