Shearing and order in vibrationally fluidized 3D granular flows
Abstract: We 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. Experiments are performed with both mono- and poly-disperse
spheres over a range of packing fractions. With increasing shear rate,
we see a change in the shape of the shear band accompanied by a
transition to decreased order of the mono-disperse particles. We will
present velocity profiles and distributions based on particle tracking,
providing insight into the statistical properties of shear systems. In
addition, we measure corresponding local forces due to the presence of
shifting force chains. This work has been support by the NASA
Microgravity Program, under grant NAG3-2372.