Efecto de la geometría de la deformación en la deformación plástica de agregados policristalinosresultados experimentales en caliza de Solnhofen

Résumé

Several high temperature deformation tests in Solnhofen limestone have been run using different rock experimental configurations: axi-symmetric shortening and extension, and direct shear. The aim is to establish the relation between the strain geometry we imposed to the specimen and the type o f crystallographic preferred orientation that forms in the aggregate, taking into account that intracrystalline plasticity is the predominant deformation mechanism. We produced non-plane strain geometries, such as constrictional and flattening deformations in axi-symmetric extension and compression tests, respectively, but also geometries close to plane strain in direct shear experiments. The arrangement o f slip systems in the deformed aggregates depends on the orientation of the principal strain axes and on the boundary conditions of the experimental setting. We combined the use o f pole figures and inverse pole figures to characterise, respectively, the asymmetry of deformation and the orientation of the extension and compression directions in 3D. This approach allow us to track changes in 3D strain geometry in specimens deformed heterogeneously and to have access to geometries which are not producible separately.