Discontinuous yielding of pristine micro-crystals - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Comptes Rendus. Physique Année : 2021

Discontinuous yielding of pristine micro-crystals

Résumé

We study the mechanical response of a dislocation-free 2D crystal under homogenous shear using a new mesoscopic approach to crystal plasticity, a Landau-type theory, accounting for the global invariance of the energy in the space of strain tensors while operating with an infinite number of equivalent energy wells. The advantage of this approach is that it eliminates arbitrariness in dealing with topological transitions involved, for instance, in nucleation and annihilation of dislocations. We use discontinuous yielding of pristine micro-crystals as a benchmark problem for the new theory and show that the nature of the catastrophic instability, which in this setting inevitably follows the standard affine response, depends not only on lattice symmetry but also on the orientation of the crystal in the loading device. The ensuing dislocation avalanche involves cooperative dislocation nucleation, resulting in the formation of complex microstructures controlled by a nontrivial self-induced coupling between different plastic mechanisms.
Fichier principal
Vignette du fichier
CRPHYS_2021__22_S3_A19_0(4).pdf (12.94 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03366231 , version 1 (05-10-2021)

Identifiants

Citer

Oguz Umut Salman, Roberta Baggio, Brigitte Bacroix, Giovanni Zanzotto, Nikolai Gorbushin, et al.. Discontinuous yielding of pristine micro-crystals. Comptes Rendus. Physique, 2021, ⟨10.5802/crphys.77⟩. ⟨hal-03366231⟩
40 Consultations
14 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More