Compaction of granular material inside confined geometries

Frontiers in Physics

Sandnes, Bjø¹  rnar¹  Eriksen, Jon A.²  Dumazer, Guillaume²  Marks, Benjy² 

[1] College of Engineering, Swansea University, Swansea, UK;Condensed Matter Physics, Department of Physics, University of Oslo, Oslo, Norway

关键词: Granular material;    Janssen stress;    boundary effects;    Confinement;    Deformable media;    Hele-Shaw cell;    discrete element model;    Micromechanics.;   

DOI  :  10.3389/fphy.2015.00041

学科分类：物理（综合）

来源: Frontiers

【 摘 要 】

In both nature and the laboratory, loosely packed granular materials are often compacted inside confined geometries. Here, we explore such behaviour in a quasi-two dimensional geometry, where parallel rigid walls provide the confinement. We use the discrete element method to investigate the stress distribution developed within the granular packing as a result of compaction due to the displacement of a rigid piston. We observe that the stress within the packing increases exponentially with the length of accumulated grains, and show an extension to current analytic models which fits the measured stress. The micromechanical behaviour is studied for a range of system parameters, and the limitations of existing analytic models are described. In particular, we show the smallest sized systems which can be treated using existing models. Additionally, the effects of increasing piston rate, and variations of the initial packing fraction, are described.

【 授权许可】

CC BY