Actionneur à architecture antagoniste à base d'alliages à mémoire de forme : Modèle thermomécanique simplifié pour la commande

Memory effect of shape memory alloys (SMA) is obtained under a thermomechanical loading. This can be used and be at the origin of the development of new generation of actuators. The positive point of these actuators is the mechanism simplification but the complex behaviour of these materials makes their control difficult. In this paper a simplified thermomechanical model has been developed to define a scheme of control taking into account the physique of the system. This model permits the description of the non linearity of SMA behaviour under thermomechanical loadings pour simple structures like springs. Two type of actuators have been studied: a simple actuator based on a SMA spring under a constant loading and an antagonist actuator based on the combination of a SMA spring and an elastic one. Mots-clefs : Actionneurs ; alliage a memoire de forme ; commande