Eur. Phys. J. B 77, 505-521 (2010)
https://doi.org/10.1140/epjb/e2010-10469-1

The effects of grain shape and frustration in a granular column near jamming

¹ Institut de Physique Théorique, IPhT, CEA Saclay, and URA 2306, CNRS, 91191 Gif-sur-Yvette Cedex, France
² S.N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, 700098 Calcutta, India

Corresponding author: ^a jean-marc.luck@cea.fr

Received: 17 June 2010
Published online: 12 October 2010

Abstract

We investigate the full phase diagram of a column of grains near jamming, as a function of varying levels of frustration. Frustration is modelled by the effect of two opposing fields on a grain, due respectively to grains above and below it. The resulting four dynamical regimes (ballistic, logarithmic, activated and glassy) are characterised by means of the jamming time of zero-temperature dynamics, and of the statistics of attractors reached by the latter. Shape effects are most pronounced in the cases of strong and weak frustration, and essentially disappear around a mean-field point.