Mechanical noise dependent Aging and Shear Banding behavior of a mesoscopic model of amorphous plasticity

Damien Vandembroucq (1) , Stéphane Roux (2)

1 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
2 LMT - Laboratoire de Mécanique et Technologie

We discuss aging and localization in a simple ''Eshelby'' mesoscopic model of amorphous plasticity. Plastic deformation is assumed to occur through a series of local reorganizations. Using a discretization of the mechanical fields on a discrete lattice, local reorganizations are modeled as local slip events. Local yield stresses are randomly distributed in space and invariant in time. Each plastic slip event induces a long-ranged elastic stress redistribution. Mimicking the effect of aging, we focus on the behavior of the model when the initial state is characterized by a distribution of high local yield stress values. A dramatic effect on the localization behavior is obtained: the system first spontaneously self-traps to form a shear band which then only slowly widens. The higher the ''age'' parameter the more localized the plastic strain field. Two-time correlation computed on the stress field show a divergent correlation time with the age parameter. The amplitude of a local slip event (the prefactor of the Eshelby singularity) as compared to the yield stress distribution width acts here as an effective temperature-like parameter: the lower the slip increment, the higher the localization and the decorrelation time.

Mots clés: plasticity; glass; localization; shear band; mesoscopic

Domaines: Autre [cond-mat.other]

Damien Vandembroucq, Stéphane Roux. Mechanical noise dependent Aging and Shear Banding behavior of a mesoscopic model of amorphous plasticity. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2011, 84, pp.134210. ⟨10.1103/PhysRevB.84.134210⟩. ⟨hal-00588610v2⟩