26/06/2014 - Séminaire exceptionnel PIMM/F2M
Matt Miller (Cornell University, USA) donnera un séminaire exceptionnel à l'ENSAM Paris
le jeudi 26 juin à 14 heures
151, boulevard de l'Hôpital
Matt Miller est directeur adjoint du synchrotron CHESS (http://www.chess.cornell.edu) et Professeur à Cornell. Il présentera des travaux sur l'analyse de microstructures et de la réponse mécanique de polycristaux à l'aide des rayons X haute énergie : "Studying Structural Materials Using High Energy X-rays and Finite Elements"
Mechanical design with structural materials has been well-served by traditional methods for linking microstructure to mechanical properties using image-based data and mechanical testing. Modern “micrographs” might include three-dimensional microstructural models with spatially resolved orientation and/or chemical composition. Regardless of the level of detail, however, a static image often obtained post-mortem contains no information regarding how the aggregate responds to loading. Using in situ loading, high energy synchrotron x-rays are capable of continuously probing a deforming polycrystalline aggregate. These data can be used with the mathematic formalism of finite elements to build a functional, dynamic representation of the microstructure. Bringing the experimental and simulated data into coincidence builds trust in the finite element model and its ability to enable optimizations during the material design process. In this talk, several examples employing various experimental methods and material models capable of representing the elastic-plastic response of polycrystals are described. A range of materials were examined. New high energy x-ray capabilities and structural materials initiatives at the Cornell High Energy Synchrotron Source (CHESS) are described and an overview of planned CHESS upgrades is given.