FIRST STEPS OF EXPERIMENTAL VALIDATION OF A NUMERICAL MODEL ABOUT MECHANICAL BEHAVIOR OF NITI ENDODONTIC INSTRUMENTS

Oral Communication presented at the ";Forum des Jeunes Chercheurs";, Brest (France) 2011

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

L'effet mémoire des AMF est obtenu sous un chargement thermomécanique. Ceci peut être exploité et être à l'origine du développement d'actionneurs de nouvelle génération. Le point fort de ces actionneurs est la simplification du mécanisme mais le comportement complexe de ces matériaux rend la commande de l'actionneur plus difficile. Dans ce papier nous avons développé un modèle thermomécanique simplifié de ces matériaux pour établir un schéma de commande en prenant en compte la physique du système. Ce modèle permet la description du comportement non linéaire des AMF sous chargements thermomécaniques pour des structures simples telles que les ressorts. Nous nous intéressons aux actionneurs intégrant des ressorts à base d'AMF. Deux types d'actionneurs seront étudiés : un actionneur simple qui comporte un ressort sous une charge constante et un actionneur antagoniste comportant un ressort en AMF et un ressort élastique de rappel

Determination of the interaction energy in the martensitic state

8th International Symposium on Plasticity, WHISTLER, CANADA, JUL 17-21, 2000International audienc

Superelastic behavior modeling in shape memory alloys

The superelastic behavior of shape memory alloys is useful for several industrial applications. To dimension the SMA structures, the development of specified phenomenological constitutive models are necessary. In this case the identification of a transformation criterion is required. Unfortunately, accurate determination of the loading surface which characterizes the behavior during the martensitic transformation is experimentally difficult. A numerical simulation of this surface is proposed from a micromechanical model based on the self-consistent scale transition method. The effect of the various crystallographic textures on the shape of these surfaces is studied in CuZnAl alloys. The obtained results permit to choose the best texture according to the loading type. The validity of the normality law has been verified during the transformation procedure for studied textures

Fatigue life study of superelastic NiTi Shape Memory Alloys using self-heating under cyclic loading method

International audienceThis paper concerns the High Cycle Fatigue (HCF) properties of superelastic NiTi Shape Memory Alloys (SMA). Up till today, HCF fatigue of SMAs has not been much studied and, therefore, there is a lack of tools to design the SMA pieces and structures against fatigue. In this study, it is proposed to investigate the HCF properties of NiTi SMAs by using a new approach based, on one hand, on self-heating tests under cyclic loading and, on the other hand, on a probabilistic two-scale model. The proposed model permits to establish a link between self-heating phenomena and the fatigue properties of the material. Finally, our approach is validated by comparing the model predictions to the experimental results obtained with classical HCF fatigue tests

Out-of-hours emergency dental hospital service: Creation and preliminary results

International audienc

Out-of-hours emergency dental hospital service: Creation and preliminary results

International audienc