From earthquakes faults to the nanoscale deformation of everyday
materials, many solids exhibit a localization of shear when subjected to
external stresses. In contrast, fluid systems do not, instead showing
linear velocity profiles. The investigation of shear profiles in
granular systems is particularly interesting since these materials have
some characteristics of each.
I will present initial results from a 3D annular shearing experiment
which can be vibrationally excited from below. This provides two
separate means of injecting energy into the system, and we are able to
study the interaction of the two effects in the formation of shear
bands.