Initial stages of shear localization investigated by simulated tensile tests of metallic glass nanowires
Eric Homer (Brigham Young University), Christopher Schuh (Massachusetts Institute of Technology)
Slip Avalanches in Amorphous Metals
Mon 10:45 - 12:15
Barus-Holley 168
Capturing the initial stages of nucleation and propagation of shear bands presents a significant challenge due to the limited time and length scales involved. To elucidate the nature of these initial stages under experimentally relevant conditions, we use shear transformation zone (STZ) dynamics simulations. This methodology provides a coarse-grained view of the deformation in metallic glasses while preserving the level of detail required to investigate the kinetics and conditions of the early stages of shear banding behavior. Simulated tensile tests of nanowires at laboratory strain rates indicate a clustering stage of STZ activity that continues until a critical nucleus is formed. This is immediately followed by a load drop and fast propagation of a nascent shear band. The energetics of this process are discussed along with size and strain rate effects observed in the simulations. Implications of the results on the effects of structure are also discussed.