Abrupt Events in Crystal Plasticity : From Uniaxial Compression to Nanoindentation

Orateur : Stefanos PAPANIKOLAOU (Department of Physics, West Virginia University, USA)

Crystal plasticity is stochastic and characterized by rare events when there are stiff spatial constraints. In nanopillars under uniaxial compression, size effects are accompanied by plastic deformation that is predominantly stochastic and abrupt with complex probability distributions of rare events. In nanoindentation studies of crystalline surfaces, size effects are accompanied by abrupt “pop-in” events that are strongly related to the constrained dislocation dynamics near a surface. The connection and range of the validity and agreement of the character of crystalline stochastic events will be discussed. We will present minimal discrete dislocation plasticity and continuum models that aim to unify observations across crystal plasticity geometries and scales. We will also discuss our experimental efforts towards the statistical understanding of nanoindentation in FCC polycrystals.

Télécharger dans mon agenda