Granular Media

A fundamental question for granular assemblies and materials is the relation between the mechanical response of the material and the structural ordering of the granular assembly or the shape of the individual grains. Although it is well known that the degree of anisotropy can change the structural order, stability, and dynamical response of a granular packing, the exact relationship is not well understood. In addition, it is often difficult to control the properties of granular materials. For example, in the case of rice, dispersion in the shape and size of the individual particles is always present. Due to these issues it is of great interest to find a model system in which specific types of ordering can be controllably prepared and compared to the dynamical response. We numerically and experimentally study a simple system of elongated grains confined in a 2D plane in which we demonstrate that specific types of ordering can be controllably produced by tuning the anisotropy of the grains.

Papers:

1. Jamming in granular polymers
   L.M. Lopatina, C.J. Olson Reichhardt, and C. Reichhardt
   Phys. Rev. E 83 061404 (2011).
   Online version
   

2. Fluctuations, jamming and yielding for a driven probe particle in disordered disk assemblies
   C.J. Olson Reichhardt, and C. Reichhardt
   Phys. Rev. E 82 051306 (2010).
   Online version
   

3. Multiscaling at point J: Jamming is a critical phenomenon
   J.A. Drocco, M.B. Hastings, C.J. Olson Reichhardt, and C. Reichhardt
   Phys. Rev. Lett 95 088001 (2005).
   Online version
   

4. Ratchet-induced segregation and transport of non-spherical grains
   J.F. Wambaugh, C. Reichhardt, and C.J. Olson
   Phys. Rev. E 65, 031308 (2002).
   Online version
   

5. Effect of grain anisotropy on ordering, stability, and dynamics in granular systems
   C.J. Olson, C. Reichhardt, M. McCloskey, and R.J. Zieve
   Europhys. Lett. 57, 904 (2002).
   Online version
   

Slides from talks

Collaborators

John Wambaugh (Duke University)

Granular Media at Los Alamos

Robert Ecke

Granular chains

We are also working on assemblies of granular chains. Our work is motivated by the experiments done at Los Alamos. Below is an image of some of these experiments of a possible granular chain gas. (Courtesy of Z. Daya)

Other granular physics groups

Argonne granular group

Jeff Urbach's group

Narayanan Menon's group

Doug Durian's group

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Last Modified: 3/25/03