Slow dynamics for elliptical particles under continuous shear and cyclic compression

Abstract

We have performed Couette shear and cyclic isotropic compression experiments on both elliptical and circular shaped particles. In sheared systems of ellipses, we have observed slow relaxation of global stress and particle velocities for a small range of packing fractions, . In isotropic compression experiment, we have studied the dynamics of isotropically jammed states by tracking the particles through cyclically compressed states. In a specific range of packing fractions, the global stress of both disks and ellipses relax. the relaxation rate depends on the packing fraction, . © 2013 AIP Publishing LLC.