Phenomenological modeling of the cyclic behavior of superelastic shape memory alloys

摘要

The cyclic hysteretic behavior of superelastic shape memory alloy (SMAs) under loading and unloading is desirable for mitigating the vibration of structures. Thus, it is necessary to investigate the cyclic behavior of SMAs. To obtain experimental data, tests of NiTi wires subjected to quasi-static cyclic loading are performed, with the completion of the transformation. The cycling effects on the hysteretic loops are formulated using the least-squares method. A modification to Lagoudas' simplified model is proposed to include the cycling effects. Based on the analysis of the experimental results, the revised cyclic model takes into consideration that the slopes of the phase transformation lines in the stress-temperature phase diagram, the residual strain and the austenite elastic modulus are cycle-dependent. Numerical simulations show that the proposed model can capture the 'classical' characteristics of the cyclic behavior of SMA, and the simulated loops closely agree with the experimental results for each cycle.