Hinkle, AdamRycroft, ChristopherShields, MichaelFalk, Michael2019-09-062017-05-05Hinkle, Adam R., Chris H. Rycroft, Michael D. Shields, and Michael L. Falk. 2017. Coarse Graining Atomistic Simulations of Plastically Deforming Amorphous Solids. Physical Review E 95: 053001.2470-00452470-0053http://nrs.harvard.edu/urn-3:HUL.InstRepos:41292901The primary mode of failure in disordered solids results from the formation and persistence of highly localized regions of large plastic strains known as shear bands. Continuum-level field theories capable of predicting this mechanical response rely upon an accurate representation of the initial and evolving states of the amorphous structure. We perform molecular dynamics simulations of a metallic glass and propose a methodology for coarse graining discrete, atomistic quantities, such as the potential energies of the elemental constituents. A strain criterion is established and used to distinguish the coarse-grained degrees-of-freedom inside the emerging shear band from those of the surrounding material. A signal-to-noise ratio provides a means of evaluating the strength of the signal of the shear band as a function of the coarse graining. Finally, we investigate the effect of different coarse graining length scales by comparing a two-dimensional, numerical implementation of the effective-temperature description in the shear transformation zone (STZ) theory with direct molecular dynamics simulations. These comparisons indicate the coarse graining length scale has a lower bound, above which there is a high level of agreement between the atomistics and the STZ theory, and below which the concept of effective temperature breaks down.en-USJournal Article2019-09-0610.1103/physreve.95.053001