Ergodic-nonergodic transition in tapped granular systems: The role of persistent contacts

  • Paula A. Gago Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional Consejo Nacional de Investigaciones Científicas y Técnicas
  • Diego Maza Departamento de Física y Matemática Aplicada, Facultad de Ciencias, Universidad de Navarra, Navarra, Spain
  • Luis A. Pugnaloni Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional Consejo Nacional de Investigaciones Científicas y Técnicas
Keywords: Ergodicity breaking, Tapped Granular Packs

Abstract

Static granular packs have been studied in the last three decades in the frame of a modified equilibrium statistical mechanics that assumes ergodicity as a basic postulate. The canonical example on which this framework is tested consists in the series of static configurations visited by a granular column subjected to taps. By analyzing the response of a realistic model of grains, we demonstrate that volume and stress variables visit different regions of the phase space at low tap intensities in different realizations of the experiment. We show that the tap intensity beyond which sampling by tapping becomes ergodic coincides with the forcing necessary to break all particle-particle contacts during each tap. These results imply that the well-known "reversible" branch of tapped granular columns is only valid at relatively high tap intensities.

Received: 2 November 2015,  Accepted: 22 December 2015; Edited by: C. S. O'Hern; Reviewed by: A. Baule, Queen Mary University of London, UK.; DOI: http://dx.doi.org/10.4279/PIP.080001

Cite as: P A Gago, D. Maza, L A Pugnaloni, Papers in Physics 8, 080001 (2016)

This paper, by P A Gago, D. Maza, L A Pugnaloni, is licensed under the Creative Commons Attribution License 3.0.
Open Review
Published
2016-01-12
How to Cite
Gago, P. A., Maza, D., & Pugnaloni, L. A. (2016). Ergodic-nonergodic transition in tapped granular systems: The role of persistent contacts. Papers in Physics, 8, 080001. https://doi.org/10.4279/pip.080001
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Articles