title: Shear- and vibration-induced order-disorder transitions in granular media.
abstract: By molecular dynamics simulations we investigate the order-disorder transitions induced in granular media by an applied drive combining vibrations and shear. As the steady state is attained, the pack is found in disordered configurations for comparatively high intensities of the drive; conversely, ordering and packing fractions exceeding the random close packing are found when vibrations and shear are weak. As forcing amplitudes get smaller, we find diverging time scales in the dynamics, as the system enters a jamming region. Under this perspective, our picture supports the intuition that externally applied forcing has, in driven granular media, a role similar to temperature in thermal systems.
authors.affiliation: CNISM and Department of Information Engineering, Second University of Naples, 81031, Aversa CE, Italy. picaciam@na.infn.it
authors.forename: M
authors.initials: M
authors.lastname: Pica Ciamarra
authors.forename: A
authors.initials: A
authors.lastname: Coniglio
authors.forename: D
authors.initials: D
authors.lastname: De Martino
authors.forename: M
authors.initials: M
authors.lastname: Nicodemi
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D004548:Elasticity; D044085:Microfluidics / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D015233:Models, Statistical; D044367:Phase Transition; D033081:Shear Strength; D013314:Stress, Mechanical; D014732:Vibration
chemical_list: D003102:Colloids