Rare events and disorder control the brittle yielding of well-annealed amorphous solids

Misaki Ozawa (1) , Ludovic Berthier (2) , Giulio Biroli (3) , Gilles Tarjus (4)

1 LPENS - Laboratoire de physique de l'ENS - ENS Paris
2 L2C - Laboratoire Charles Coulomb
3 Systèmes Désordonnés et Applications
4 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée

We use atomistic computer simulations to provide a microscopic description of the brittle failure of amorphous materials, and we assess the role of rare events and quenched disorder. We argue that brittle yielding originates at rare soft regions, similarly to Griffiths effects in disordered systems. We numerically demonstrate how localized plastic events in such soft regions trigger macroscopic failure via the propagation of a shear band. This physical picture, which no longer holds in poorly annealed ductile materials, allows us to discuss the role of finite size effects in brittle yielding and reinforces the similarities between yielding and other disorder-controlled nonequilibrium phase transitions.

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

Misaki Ozawa, Ludovic Berthier, Giulio Biroli, Gilles Tarjus. Rare events and disorder control the brittle yielding of well-annealed amorphous solids. Physical Review Research, 2022, 4 (2), pp.023227. ⟨10.1103/PhysRevResearch.4.023227⟩. ⟨hal-03758384⟩