What is random close packing and random loose packing

Asked by Huang peilun on 2019-12-12

Hi,
I have trouble with the 'makecloud'
The document says makecloud create random very loose packing enclosed in a parallelepiped.

What is random very loose packing? Does it have a mathematical definition?
I've seen several articles but didn't understand the distribution clearly.

Thanks in advance!

Question information

Language:
English Edit question
Status:
Solved
For:
Yade Edit question
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Solved by:
Robert Caulk
Solved:
2019-12-15
Last query:
2019-12-15
Last reply:
2019-12-12
Best Robert Caulk (rcaulk) said : #1

Hello,

>What is random very loose packing?

I guess the documentation describes it best [1]:

" The resulting packing conforms in fact a gas-like state (see Cloud denomination) with no contacts between particles. Usually used as a first step for packing generation, before subsequent mechanical loading that will confer a solid-like nature to the packing. "

On the other hand, a dense packing would be a packing where the spheres are touching to create a structure i.e. the result of applying confining pressure to that loose packing (or internalCompaction i.e. growing sphere radii). This is what the triax example script demonstrates [2] and what randomDensePack [3] does in the background.

Cheers,

Robert

[1]https://yade-dem.org/doc/yade.pack.html#yade._packSpheres.SpherePack.makeCloud
[2]https://gitlab.com/yade-dev/trunk/blob/master/examples/triax-tutorial/script-session1.py
[3]https://yade-dem.org/doc/yade.pack.html#yade.pack.randomDensePack

Huang peilun (hpl16) said : #2

Thanks Robert Caulk, that solved my question.