  We study strain-controlled plastic deformation of crystalline solids via
two-dimensional discrete dislocation dynamics simulations. To this end, we
characterize the average stress-strain curves as well as the statistical
properties of strain bursts and the related stress drops as a function of the
imposed strain rate and the stiffness of the specimen-machine system. The
dislocation system exhibits strain rate sensitivity such that a larger imposed
strain rate results in a higher average stress at a given strain. In the limit
of small strain rate and driving spring stiffness, the sizes and durations of
the dislocation avalanches are power-law distributed up to a cutoff scale, and
exhibit temporally asymmetric average shapes. We discuss the dependence of the
results on the driving parameters, and compare our results to those from
previous simulations where quasistatic stress-controlled loading was used.
