Simulation of shape memory alloy wire actuator behavior under arbitrary thermo-mechanical loading

Shape memory alloy (SMA) wires are becoming potential candidates as actuators due to their high stress-generating and strain-recovery capabilities. As actuators, these wires undergo arbitrary thermo-mechanical loading. For an efficient design, one requires a model to simulate their behavior under any stress-temperature situation. In this study, based on an existing phase kinetics dependent phenomenological model, an algorithm capable of simulating SMA wire behavior under an arbitrary loading situation has been developed and implemented. To demonstrate this, two cases have been simulated. In the first case, the behavior of an SMA wire undergoing varying stress and temperature while actuating a single degree of freedom manipulator has been simulated. The results are found to illustrate the discrepancies reported in the literature. The behavior of two antagonistically placed and independently activated SMA wires is modeled and simulated in the second case, where the results qualitatively agree with the existing experimental results.