De l'impression 3d en céramique
Mesurer la déformation du sel, pour l'aménagement de réservoirs en cavités salines
Electromagnetic forming process for metallic pieces
Amélioration de la performance des éoliennes
Vers un stockage géologique du C02 avec impuretés
Lutz ZYBELL, en visite au Centre des Matériaux, donnera un séminaire exceptionnel le 2 juin 2015 à 11h.
Résumé : The ductile failure behavior of nodular cast iron is well understood for loading under intermediate and high stress triaxiality. This process is usually governed by nucleation, growth and coalescence of voids. In nodular cast iron, the graphite particles debond under tension loading from the metallic matrix and thereby relatively large voids develop. However, there is only little knowledge about the failure mechanisms under shear loading. Therefore, in situ experiments with large flat shear specimens have been performed at beamline ID15a of the European Synchrotron Radiation Facility (ESRF). By using X-ray laminography for 3D observation, the nodular cast iron can be studied during the entire deformation process in a region of interest within the specimen. The mechanisms leading to ductile failure under shear loading such as shear band formation, void shape and void volume evolution are investigated in detail with micrometer resolution. Furthermore, the results are compared to predictions of a shear-modified GTN model.