title: Relevance of system size to the steady-state properties of tapped granular systems.
abstract: We investigate the steady-state packing fraction ϕ and force moment tensor Σ of quasi-two-dimensional granular columns subjected to tapping. Systems of different height h and width L are considered. We find that ϕ and Σ, which describe the macroscopic state of the system, are insensitive to L for L>50d (with d the grain diameter). However, results for granular columns of different heights cannot be conciliated. This suggests that comparison between results of different laboratories on this type of experiments can be done only for systems of same height. We show that a parameter ɛ=1+(Aω)2/(2gh), with A and ω the amplitude and frequency of the tap and g the acceleration of gravity, can be defined to characterize the tap intensity. This parameter is based on the effective flight of the granular bed, which takes into account the h dependency. When ϕ is plotted as a function of ɛ, the data collapses for systems of different h. However, this parameter alone is unable to determine the steady state to be reached since different Σ can be observed for a given ɛ if different column heights are considered.
authors: Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional, Av. 60 Esq. 124, 1900 La Plata, Argentina.|Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
authors: Paula A
authors: PA
authors: Gago
authors: Departamento de Física y Matemática Aplicada, Facultad de Ciencias, Universidad de Navarra, Irunlarrea S/N, 31080 Pamplona, Spain.
authors: Diego
authors: D
authors: Maza
authors: Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional, Av. 60 Esq. 124, 1900 La Plata, Argentina.|Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
authors: Luis A
authors: LA
authors: Pugnaloni