LIGGGHTS® - User Forum

Hello Christoph, hello all,

I am supposed to help to administrate a computing cluster and we are using liggghts and would like to stay up-to-date using git. For some reason we have problems accessing the git repository:

>git clone git://cfdem.git.sourceforge.net/gitroot/cfdem/liggghts myliggghts
Initialized empty Git repository in /home/hoefert/programs/test/liggghts/myliggghts/.git/
fatal: Unable to look up cfdem.git.sourceforge.net (port 9418) (Name or service not known)
fetch-pack from 'git://cfdem.git.sourceforge.net/gitroot/cfdem/liggghts' failed.

Hello.
How to generate a stress-free random dense packing with prescribed porosity and radius distribution? Is there some hints?

Hi,
I want to rotate a cylindrical mesh along y-axis. It is not rotating along axial direction but rorating some point outside the cylinder:

fix cad all mesh/gran/stressanalysis STL.stl 3 0.01 -40 -20 -50 90. 0. 0.
..
..

fix rotcad all move/mesh/gran rotate 0 0 0.0 0 1 0 0.5 cad

How to make it still( no translational motion), just rotating along axial direction?
Thanks for advising me,
Ram

Hello.
How can I enable / disable the friction during the simulation?
I want to generate an initial package without friction, then the friction enable and continue the simulation.
Thanks.

Hi,
fix pour/dev/packing can be used with STL file. I mean i put STL mesh in box and then apply this command for packing. Is it valid way of doing? I guess this command uses whole simulation box for inserting particles including STL.
Thanks,
Ram

Hi,
I want to pack particles of two different diameters (0.003 and 0.0034). Starting from lower values of diameters. how can I confirm that after growing radius the final form of packing consists of the required diameters?
Thanks for help,
R

Hi,
I am a newbie to Linux and LIGGGHTS. I'd appreciate if anyone can tell me how to upgrade LIGGGHTS from old 1.1.10 to the latest version. Thanks!

Lenard

Hi,
I'm having problems inserting particles.
I'm using pour/dev/packing command.
After few iterations they jump to +Z very quickly like rockets and all crash.
My file follows:

************************************************
atom_style granular
atom_modify map array
boundary m m m
newton off
communicate single vel yes
units si

region reg block -0.015 0.015 -0.015 0.015 -0.32 10 units box
create_box 1 reg
neighbor 0.0200 bin
neigh_modify delay 0

# Material properties required for new pair styles

Hey all,

I've modified the basic 'packing' example, to have 3 particle types with different properties (instead of 1 type) and i'm trying to generate a random packing of this system. (3 types of particles each having its own radius and density). I don't try to make them grow, so I removed the growing radius part commands.

Anyway, when I visualize the system with Paraview, I see that I only get one type of particles, all with the same size, instead of the specified distribution of particles as seen in my script.

Hi,
I have simulation box filled with particles, I want to move cluster of some particles in this box. To do so, i defined one spherical region and then apply following command:
....
....
region mySphere sphere .........
group myGroup region mySphere
fix 1 myRigid rigid group 1 myGroup
...
...

Then I want to move this as spherical body made of particle in the simulation box consists of other particles.
Is this right way of doing this? When i run the simulation then it prompts:

447 atoms in group myGroup
ERROR: One or zero atoms in rigid body