Atomistic Modeling at Experimental Strain Rates:  Plasticity in Amorphous Solids

Atomistic Modeling at Experimental Strain Rates:  Plasticity in Amorphous Solids

Harold S. Park

Harold S. Park

Boston University, Department of Mechanical Engineering

Boston University, Department of Mechanical Engineering

I will present a new computational approach that couples a recently developed potential energy surface exploration technique with mechanical deformation to study the deformation of atomistic systems at strain rates that are much slower, i.e. experimentally-relevant, as compared to classical molecular dynamics simulations.  I will then discuss the new insights into the plasticity of amorphous solids that are obtained using this new approach, with a particular emphasis on how the shear transformation zone characteristics, which are the amorphous analog to dislocations in crystalline solids, undergo a transition that is strain-rate and temperature-dependent.  More generally, I will also discuss how the proposed approach predicts differences in deformation mechanisms in comparison to scaling the results of classical molecular dynamics simulations down to experimental strain rates.

I will present a new computational approach that couples a recently developed potential energy surface exploration technique with mechanical deformation to study the deformation of atomistic systems at strain rates that are much slower, i.e. experimentally-relevant, as compared to classical molecular dynamics simulations.  I will then discuss the new insights into the plasticity of amorphous solids that are obtained using this new approach, with a particular emphasis on how the shear transformation zone characteristics, which are the amorphous analog to dislocations in crystalline solids, undergo a transition that is strain-rate and temperature-dependent.  More generally, I will also discuss how the proposed approach predicts differences in deformation mechanisms in comparison to scaling the results of classical molecular dynamics simulations down to experimental strain rates.