Molecular simulation study of the transition from anelasticity to plasticity in amorphous solid

Anelasticity, an inherent characteristic of amorphous solids, holds a significant role in comprehending how these materials relax and deform. Nevertheless, owing to the absence of long-range order in amorphous solids, unravelling the structural origins of anelasticity and distinguishing it from plasticity has remained a challenging task. In this research, we delve into the transition from anelasticity to plasticity within a two-dimensional model glass, making use of the frozen matrix method. Through manipulation of control parameters in the amorphous solid, we succeed in identifying three distinct mechanical behaviours: elasticity, anelasticity, and plasticity. Our exploration of how finite size influences these mechanical behaviours unravels a clear distinction between anelasticity and plasticity. Anelasticity acts as a crucial bridge, connecting the domains of elasticity and plasticity within amorphous materials. Moreover, our observations indicate that anelastic events remain localized, whereas plastic events exhibit subextensive characteristics. The transition from anelasticity to plasticity mirrors the entanglement of long-range interactions among element excitations. This study contributes valuable insights into the fundamental nature of anelasticity as an essential property of element excitations in amorphous solids.