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The bias on radii is fixed in last revison (r1865).
Bruno Chareyre a écrit :
chiara.modenese@xxxxxxxxx a écrit :
The initial positioning of spheres is done by generating random
(x,y,z) and checking if a sphere of radius R (R also randomly
generated with respect to a uniform distribution between mean-std_dev
and mean+std_dev) can be inserted at this location without overlaping
quick question on one aspect of the Triaxial Test. As a beginner, I
am just trying to run some triaxial tests but I have got this error
Exceeded 3000 tries to insert non-overlapping sphere to packing. Only
1055 spheres was added, although you requested 2000
If it the sphere overlaps, you generate new (x,y,z)'s until you find a
suitable place for the new sphere (*). This explains the message you
have : after 3000 trial-and-error, the sphere couldn't be placed, so
the algorithm stops.
I guess you tried to generate a dense packing, which is not possible
with this method. You should keep the default value of porosity.
The dense state will be obtained in the second step (compaction, see
BTW, could you also explain me the meaningful of the following
variables, since I was unable to find where actually they are
employed in the code.
Compaction is done (1) by moving rigid boxes or (2) by increasing the
sizes of the particles. Both algorithm needs numerical parameters to
prevent instabilities. For instance, with method (1) maxWallVelocity
is the maximum wall velocity, with method (2) finalMaxMultiplier is
the max value of the multiplier applied on sizes.
(*) I just realized there is a bias in radii generation. If the sphere
does not fit at (x,y,z), a new R is generated. Which means small R
tend to be a bit more frequent that big R, even though the
distribution is supposed to be uniform between Rmin and Rmax. I'll
commit a fix in a few minutes.
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