Granular material ↩

Metadata 
aliases: [Granular materials, granular material, granular materials]
shorthands: {}
created: 2022-05-03 16:13:12
modified: 2022-05-03 16:45:17

Definition: A collection of distinct macroscopic particles1 (to be described classically)

The time evolution of the particles follow Newton's equations. The forces present:

Examples of granular materials

Snow, rice, grains, sand, …

Behavior

The concept of granular materials is easy to grasp and we come in contact with them constantly, however they behave differently than solids or liquids and gases, exhibiting a lot of complex behavior.

Shear zone

When shearing a Newtonian liquid, we observe a linear velocity profile between the shearing plates, having a constant velocity gradient.
However, in granular materials, the shearing becomes compacted, only occurring in a smaller zone, with a non-constant velocity gradient. This zone is called the shear zone. The particles of the material outside of this zone remain mostly stationary throughout the motion.

This zone changes over time. An example of this can be seen here (the black patch is the shearing zone):

And the same example with the particles visible:

  1. Ucsb.edu. (2022). Granular Materials. [online] Available at: https://web.physics.ucsb.edu/~complex/research/granular.html#Granular [Accessed 3 May 2022].
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