Résumé
The present work deals with solid-solid phase change in shape memory alloys and is founded on a global and local construction of energy balance during load-unload cycles. Such constructions require information derived from digital image correlation (DIC) and infrared thermography (IRT). Indeed, these techniques provide discrete field measurements, invaluable to characterize and identify the material behaviour but also lead to a better distinction between "material" and "structure" effects at the observation scale imposed by the optical systems. DIC gives access to kinematic data and to the heterogeneous character of deformation fields. Associated with IRT, it allows tracking the temperature of material elements and estimating the dissipation and/or coupling heat sources that accompany the deformation mechanisms. During cyclic tensile tests, the energy fields associated with CuAlBe and CuZnAl single crystals revealed the propagation of the phase change front. The heat involved in the transformation was essentially latent heat of phase change, the mechanical energy dissipation remaining calorimetrically negligible. A deliberately simple mono-variant model is proposed within the framework of the generalized standard materials formalism in which phase change appears as an anisothermal coupling mechanism, with zero intrinsic dissipation.