We study the formation of standing waves on the surface of two-dimensional vibrated granular system, using molecular dynamics simulations. Two distinct regimes are observed at low and high vibration frequencies. At low frequency, the standing waves are maintained by a sizable fraction of...

We briefly review a Statistical Mechanics approach for the description of granular materials following the original ideas developed by Edwards. We show that Edwards’ assumptions works very well for a class of lattice models and we discuss some recent analytic results obtained in such a...

We have performed experiments of axial segregation in the Oyama's drum. We have tested binary granular mixtures during very long times. The segregation patterns have been captured by a CCD camera and spatio-temporal graphs are created. We report the occurrence of instabilities which can last...

We study the stability of the Maxwell–Boltzmann (i.e., Gaussian) distribution for the density of states at equilibrium, against an arbitrary choice of the friction in the Langevin equation. We find that this distribution is Gaussian, if and only if the friction is Lipschitz continuous. In...

A quantitative comparison of the pore space geometry for three natural sandstones is presented. The comparison is based on local porosity theory which provides a geometric characterization of stochastic microstructures. The characterization focusses on porosity and connectivity fluctuations....

Conventional and high-speed video imaging was used to observe surface waves in vertically oscillated, thin layers of dry, noncohesive granular material. The onset of wave formation is pressure dependent and sensitive to the preparation of the particle surface. The dispersion relation of these...

Based on general principles of metastable states and the mechanics of continuous media, the kinetic equation of settlement of granular material subjected to low level vibration and elastic stresses is developed. Because of confining pressure, the material remained nearly as a solid block and...

Beverloo’s law describes the flow rate of grains discharging from hoppers, where the assumption of a free-fall arch (FFA) is very useful in understanding the physical picture of this process. The FFA has been observed in previous experiments but a clear systematic study of the FFA is still...

The shape of convective cell at the onset of heap formation in the Faraday experiment with fine granular materials is studied in a simple experiment. The motion of fine grains are found to be confined in a single thin conical cell instead of a pair of convective cells as considered previously....

In an earlier paper, Ngan (Phys. Rev. E 68 (2003) 011301) proposed a statistical mechanics-based theory to predict the mathematical form of the probability force distribution of contact forces in stressed granular packings. However, the wrong choice of the mean-force constraint in that work...