title: Silo collapse under granular discharge.
abstract: We investigate, at a laboratory scale, the collapse of cylindrical shells of radius R and thickness t induced by a granular discharge. We measure the critical filling height for which the structure fails upon discharge. We observe that the silos sustain filling heights significantly above an estimation obtained by coupling standard shell-buckling and granular stress distribution theories. Two effects contribute to stabilize the structure: (i) below the critical filling height, a dynamical stabilization due to granular wall friction prevents the localized shell-buckling modes to grow irreversibly; (ii) above the critical filling height, collapse occurs before the downward sliding motion of the whole granular column sets in, such that only a partial friction mobilization is at play. However, we notice also that the critical filling height is reduced as the grain size d increases. The importance of grain size contribution is controlled by the ratio d/√[Rt]. We rationalize these antagonist effects with a novel fluid-structure theory both accounting for the actual status of granular friction at the wall and the inherent shell imperfections mediated by the grains. This theory yields new scaling predictions which are compared with the experimental results.
authors.affiliation: Departamento de Física, Universidad Simón Bolívar, Apartado Postal 89000, Caracas 1080-A, Venezuela and PMMH, ESPCI, CNRS (UMR 7636) and Université Paris 6 & Paris 7, 75005 Paris, France.
authors.forename: G
authors.initials: G
authors.lastname: Gutiérrez
authors.affiliation: Departamento de Física, Universidad Simón Bolívar, Apartado Postal 89000, Caracas 1080-A, Venezuela.
authors.forename: C
authors.initials: C
authors.lastname: Colonnello
authors.affiliation: PMMH, ESPCI, CNRS (UMR 7636) and Université Paris 6 & Paris 7, 75005 Paris, France and Université Rennes 1, Institut de Physique de Rennes (UMR UR1-CNRS 6251), Bat. 11A, Campus de Beaulieu, F-35042 Rennes, France.
authors.forename: P
authors.initials: P
authors.lastname: Boltenhagen
authors.affiliation: Departamento de Física, Universidad Simón Bolívar, Apartado Postal 89000, Caracas 1080-A, Venezuela.
authors.forename: J R
authors.initials: JR
authors.lastname: Darias
authors.affiliation: PMMH, ESPCI, CNRS (UMR 7636) and Université Paris 6 & Paris 7, 75005 Paris, France and Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, 04510 Mexico D.F., Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Peralta-Fabi
authors.affiliation: Nonlinear Physical Chemistry Unit, Université libre de Bruxelles (ULB), CP231, 1050 Brussels, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Brau
authors.affiliation: PMMH, ESPCI, CNRS (UMR 7636) and Université Paris 6 & Paris 7, 75005 Paris, France.
authors.forename: E
authors.initials: E
authors.lastname: Clément
mesh_terms: D000062:Accidents, Occupational; D017276:Friction; D006874:Hydrostatic Pressure; D008962:Models, Theoretical; D010316:Particle Size