Towards a relevant set of state variables to describe static granular packings
arXiv:1002.3264 · doi:10.1103/PhysRevE.82.050301
Abstract
We analyze, experimentally and numerically, the steady states, obtained by tapping, of a 2D granular layer. Contrary to the usual assumption, we show that the reversible (steady state branch) of the density--acceleration curve is nonmonotonous. Accordingly, steady states with the same mean volume can be reached by tapping the system with very different intensities. Simulations of dissipative frictional disks show that equal volume steady states have different values of the force moment tensor. Additionally, we find that steady states of equal stress can be obtained by changing the duration of the taps; however, these states present distinct mean volumes. These results confirm previous speculations that the volume and the force moment tensor are both needed to describe univocally equilibrium states in static granular assemblies.
5 pages, 3 figures
References in corpus (7)
- Stationary state volume fluctuations in a granular medium
- Entropy and Temperature of a Static Granular Assembly
- Entropy maximization in the force network ensemble for granular solids
- Thermodynamics and Statistical Mechanics of dense granular media
- Ensemble Theory for Force Networks in Hyperstatic Granular Matter
- Identification of arches in 2D granular packings
- High intensity tapping regime in a frustrated lattice gas model of granular compaction