yade-dev team mailing list archive

[Janek Kozicki <janek_listy@xxxxx>]

As a good practice for me, to get used to new yade, I want to put my
algorithm for generating concrete with rock aggregates in it.
Basically it is a yet another sphere pack, except that it can also
stuff steel fibres in there.

A first question do we need another sphere pack in yade? Maybe mine
has something that others don't have?

It is aimed at generating a distribution of spheres (inside a
concrete speciemen, but it can be spheres for triaxial test, or
others too).

It is using radius according to some sieve curve which is controlled
by two paramters: mean value and std deviation, assuming Gaussian
distribution around the mean radius.  In fact it spits out a graph of
sieve curve for generated sample. But I don't know how to do it in a
"modern" python way, hope you can tell me ;)

The second parameter is the volume percentage of those spheres, in
fact the opposite of porosity. There are two culprits: with low
density of aggregates (high porosity), they will not touch each
other, because they were intended to be inside a concrete. If you
just use such spheres as is, it will be a cloud. On the contrary,
high density of spheres (low porosity) allows few of those spheres to
overlap which will result in some explosions (if you do not put them
inside a concrete speciemen, but use them as spheres). But I think
that those explosions will be manageable.

It works in a very plain way: no material parameters, just the
geometry. You provide a box and you get spheres coordinates and
sphere radii.

I don't know if you already have such a sphere generator? For me it
will be a useful exercise. And it will mean for me that I am porting
a small part of Lattice code over to new yade.

For start, I suppose that It will just generate spheres, since there
is no meaningful way currently in which it could output linesegments
that are the steel fibres, right?


So, I have found following sphere packers in the code:

  def regularOrtho
  def regularHexa
  def filterSpherePack
  def randomDensePack
  def triaxialPack

and something in pkg/dem/DataClass/SpherePack.cpp

Also I know that Vincent and JF has done something. But I have no
idea where it is.


Now, the stupid question: where should I put that C++ code? My first
candidate would be to add another method into SpherePack.cpp which
generates spheres using my algorithm?

Another question: how are the clumps behaving now? Do I have to use
wm3, or eigen? Does scons check if eigen library is installed?

best regards
-- 
Janek Kozicki                               http://janek.kozicki.pl/  |