  A Phenomenological Mesoscopic Field Dislocation Mechanics (PMFDM) model is
developed, extending continuum plasticity theory for studying initial-boundary
value problems of small-scale plasticity. PMFDM results from an elementary
space-time averaging of the equations of Field Dislocation Mechanics (FDM),
followed by a closure assumption from any strain-gradient plasticity model that
attempts to model effects of geometrically-necessary dislocations (GND) only in
work-hardening.
