Structuro-elasto-plasticity (StEP) model for plasticity in disordered solids*

Disordered solids all yield at a common shear strain of about 3%, but the behavior beyond yield is different for different systems and for systems with different histories. Foams can deform indefinitely without fracturing, many systems exhibit crackling noise or avalanche behavior, and still others exhibit shear banding and brittle fracture. A phenomenological model capable of capturing and predicting these behaviors from microscopic properties and interactions has long been sought. We previously studied avalanches in an athermal, jammed packing of Hertzian particles that is sheared quasistatically, and disentangled the interplay between rearrangements, strain, and softness, a machine-learned structural descriptor that predicts the propensity of a particle to rearrange. We now use those microscopic results to construct a coarse-grained structuro-elasto-plasticity (StEP) model and explore its behavior.