Functional Fatigue of Shape Memory Alloys

Abstract

Shape Memory Alloys (SMAs) provide an exceptional opportunity for the design of novel actuators, however their application is limited by the fatigue mode of failure. Fatigue prediction is relatively well defined for traditional materials, however, shape memory alloys display two distinct fatigue failure modes. These are structural fatigue (fracture in traditional materials) and functional fatigue (loss of shape memory effect). Functional fatigue of shape memory alloys are not well defined in literature. This work provides a novel method of analysing SMA functional fatigue data, especially when comparing a large range of potential operating conditions.