The formation and development of strain localization via shear banding
is examined for an orthotropic material for the purpose of studying t
he effect of the plastic spin and the anisotropy upon the strain local
ization. First, the material instability analysis is carried out for a
n orthotropic elastoplastic material with plastic spin. By way of fini
te element analysis, full numerical solution is next obtained for plan
e strain block of an elastoviscoplastic material under tension or comp
ression, and the shear band development is simulated. The results show
that the plastic spin may hasten or delay the initiation of shear ban
d development depending upon the deformation or loading type-compressi
on or tension, the initial orientation of the orthotropic axes, and th
e algebraic sign of the plastic spin.