2009/11/24 by Kiri Nichol, Alexey Zanin, Renaud Bastien +2
Physics and Astronomy · #cond-mat.other #cond-mat.soft
paper · pdf · doi:10.1103/physrevlett.104.078302
arxiv created 2009/11/24 · arxiv updated 2015/05/14
We fluidize a granular medium through localized stirring and probe the mechanical response of quiescent regions far away from the main flow. In these regions the material behaves like a liquid: high-density probes sink, low-density probes float at the depth given by Archimedes' law, and drag forces on moving probes scale linearly with the velocity. The fluid-like character of the material is set by agitations generated in the stirred region, suggesting a non-local rheology: the relation between applied stress and observed strain rate in one location depends on the strain rate in another location.