Bridging kinematic measurements and crystal plasticity models in austenitic stainless steels

A Guery (1, 2) , F Latourte (1) , F Hild (2) , Stéphane Roux (2)

1 EDF - EDF
2 LMT - Laboratoire de Mécanique et Technologie

A digital image correlation procedure is developed to perform kinematic measurements on the surface of 316LN austenitic steel polycrystals. A sequence of images is acquired using a Scanning Electron Microscope (SEM) during in situ tensile tests for various mean grain sizes. To enable digital image correlation, a speckle pattern adapted to the microscopic scale is deposited onto the specimen surface by microlithography. The knowledge of the microstructure at the surface allows for kinematic measurements to be performed using an unstructured finite element mesh consistent with the grain boundaries. The same mesh is then used for the simulation of each tensile test on the experimental microstructure with the measured nodal displacements prescribed as boundary conditions. A crystal plasticity law is considered to simulate the observed strain heterogeneities. An inverse identification method is proposed for the determination of the sought constitutive parameters based on both the local displacement fields and the material homogenized behavior. The parameters associated with isotropic hardening at the grain level are thus identified.

Mots clés: Austenitic Steel; Crystal Plasticity; Digital Image Correlation; Identification; SEM

Domaines: Mécanique des matériaux [physics.class-ph]

A Guery, F Latourte, F Hild, Stéphane Roux. Bridging kinematic measurements and crystal plasticity models in austenitic stainless steels. SEM 2015 Annual Conference and Exposition on Experimental and Applied Mechanics, Jun 2015, Costa Mesa, United States. ⟨hal-01171687⟩