Europhys. Lett.
Volume 61, Number 2, January 2003
Page(s) 194 - 200
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 January 2003
DOI: 10.1209/epl/i2003-00212-8
Europhys. Lett., 61 (2) , pp. 194-200 (2003)

Collision process of a bead on a two-dimensional bead packing: Importance of the inter-granular contacts

F. Rioual, A. Valance and D. Bideau

Groupe Matière Condensée et Matériaux, UMR 6626, Université Rennes 1 F-35042 Rennes Cedex, France

(Received 23 May 2002; accepted in final form 5 November 2002)

The collision of an impacting bead on a 2D bead packing is experimentally investigated. It is found that the energy dissipated in the collision is strongly dependent on the density of inter-granular contacts in the packing. We show indeed that the energy released by the packing after the impact is increased when the density of inter-grain contacts is lowered. This increase manifests itself by means of an important augmentation of the number of grains ejected from the packing. In addition, we propose a phenomenological description of the propagation of the shock wave (induced by the impacting bead) through the packing. This description is inspired from percolation models and provides a plausible explanation for the increase of the energy released by a packing with a low density of inter-grain contacts.

45.70.-n - Granular systems.
62.20.-x - Mechanical properties of solids.
81.05.Rm - Porous materials; granular materials.

© EDP Sciences 2003