Hi,

When the spring returns immediately on unloading in ANSYS, the most likely cause is that the chosen material model and analysis temperature correspond to superelastic austenite rather than low temperature martensite. In ANSYS ensure you have selected an SMA formulation that supports thermally activated shape memory (not only superelastic behavior), and correctly entered the transformation temperatures Ms, Mf, As, Af the austenite and martensite moduli, the maximum transformation strain and the stress–temperature coupling parameters.

respected sir i selected the shape memory effect model.

I have a spring of od 5mm number of turns 18 height 20 mm and wire diameter 0.8mm. I stretch it by a weight 214gm. It gets deformed to 45 mm when I remove load it regains shape only upto 35mm. Untill I heat it upon heating it becomes 20mm. but in ansys by applying the same weight(2.1N) my spring deformed only upto 5mm. any suggestions. the transformation temperature is 65C

Try this

Temperature-dependent

• Row 1: T = 10 °C → H = 500 MPa, T_ref = 23 °C, σ_el = 120 MPa, temp_scaling = 8.3 MPa/°C, ε_tr = 0.06, E_M = 6000 MPa
• Row 2: T = 40 °C → same as Row 1
• Small viscous regularization = 1e-4 (optional; helps convergence)