  A systematic study on the different roles of the governing components of a
well-defined finite-deformation gradient crystal-plasticity model proposed by
(Gurtin, 2008b) is carried out, in order to visualize the capability of the
model in the prediction of a wide range of hardening behaviors as well as
rate-dependent, scale-variation and Bauschinger-like responses in a single
crystal. A function of accumulation rates of dislocations is employed and
viewed as a measure of formation of short-range interactions which impede
dislocation movements within a crystal. The model is first represented in the
reference configuration for the purpose of numerical implementation, and then
implemented in the FEM software ABAQUS via a user-defined subroutine (UEL). Our
simulation results reveal that the dissipative gradient-strengthening is also
identified as a source of isotropic-hardening behavior, which represents the
effect of cold work introduced by (Gurtin and Ohno, 2011). Moreover, plastic
flows in predefined slip systems and expansion of accumulation of GNDs are
distinctly observed in varying scales and under different loading conditions.
