Granular friction: A slider experiment

Peidong Yu and Robert P. Behringer
Chaos 15, 041102 (2005)
http://link.aip.org/link/?CHAOEH/15/041102/1

This video contrasts two different systems involving the shearing of granular materials in a two-dimensional setting. The first is a Couette shear system, and the second is a version of a classical rheology experiment in which a frictional slider is pulled across a frictional surface, in this case, a layer of granular material. In these two systems, the "granular material" consists of photoelastic disks that are viewed between crossed polarizers. With this arrangement, particles that subject to large forces appear brighter. In both types of experiments, filamentary structures known as force chains form. These chains tend to carry the majority of an applied force and are an important part of the dynamics. As the shearing surface in either experiment advances, force chains build up and then relax. The question then is, what role is played by such force structures, their build-ups and releases, in the evolution of these systems? The answer to this question is relevant not only to simple granular systems, but also to dynamical processes such as earthquakes, avalanches, and related phenomena in disordered systems.

Category:

Science & Technology

Tags:

• chaos
• earthquake
• avalanche
• disordered-systems

[Freddybest123]

Very interesting video that shows how the particle rheology is different with respect to liquid rheology