FTMP-based simulations and evaluations of Geometrically-Necessary Boundaries (GNBs) of dislocation

Abstract

The present study targets four representative GNBs (Geometrically Necessary Boundaries) in terms of their unified and quantitative evaluations based on the field theory of multiscale plasticity (FTMP). Discrete dislocation dynamics simulations on GNBs 2, 3, 4 and 7, whose details about the consisting dislocations have been experimentally identified and theoretically evaluated by Hong, Winther, et al., are conducted. Applying the FTMP-based duality diagram representation scheme to the formation processes reveals a systematic interrelationship that further governs the stability of the GNBs, i.e., all the GNBs exhibit a common tendency to converge ultimately to a single master curve. This leads us to propose a postulate about the stability/instability criterion that involves their dynamic interactions with external disturbances.