title: Mechanical characterization of partially crystallized sphere packings.
abstract: We study grain-scale mechanical and geometrical features of partially crystallized packings of frictional spheres, produced experimentally by a vibrational protocol. By combining x-ray computed tomography, 3D image analysis, and discrete element method simulations, we have access to the 3D structure of internal forces. We investigate how the network of mechanical contacts and intergranular forces change when the packing structure evolves from amorphous to near perfect crystalline arrangements. We compare the behavior of the geometrical neighbors (quasicontracts) of a grain to the evolution of the mechanical contacts. The mechanical coordination number Z(m) is a key parameter characterizing the crystallization onset. The high fluctuation level of Z(m) and of the force distribution in highly crystallized packings reveals that a geometrically ordered structure still possesses a highly random mechanical backbone similar to that of amorphous packings.
authors.affiliation: Department of Physics, University of Tehran, Tehran 14395-547, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Hanifpour
authors.affiliation: Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Francois
authors.affiliation: Department of Physics, University of Tehran, Tehran 14395-547, Iran.
authors.forename: S M
authors.initials: SM
authors.lastname: Vaez Allaei
authors.affiliation: Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Senden
authors.affiliation: Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Saadatfar