SMA (NiTi): The coupling between time, temperature and cycling frequency

Abstract

The main interest focuses in the necessary tools for accurate simulation of the damper behavior in their application. It's essential a well determined knowledge of the dissipated energy and of the hysteresis cycle shape for a correct simulation. The self-heating effects and the coupling between hysteresis and the relevant temperature effects associated to continuous cycling were studied. In particular, the experimental analysis concentrates in the action of cycling frequency on the hysteresis width and on the dissipated energy. The external and the self-heating temperature effects were studied. In particular, the convective actions of cooling in the conditioned air were visualized. The study of self-heating actions at extremely slow cycles, built by strain steps, shows minor latent heat dissipations in the entire sample. For trained samples, the temperature measurements establish that the transformation is "distributed" not "localized" in the complete sample. © (2013) Trans Tech Publications, Switzerland.