LIGGGHTS® - User Forum

Hey

Attached below is the code I am using.
Essentially I am pouring particles into a region and then allowing them to settle before rotating them, but I have something a bit weird going on. Between runs 1200-1400 the particles hit the mesh wall of a circular tank on the x-y plane for the first time, and then massively rebound to the extent that the majority of them travel in the positive z direction and leave the simulation domain. The defined region is inside a hollow cylindrical tube mesh which sits directly ontop of the circular tank, and definitely doesn't cross the inserted mesh.

Hi everybody,

I wonder if you guys know an easy way to generate a slab consisting of randomly oriented crystals or not. There will be particles at the atom positions.

Thanks,

Ozgur

Hello everybody,

I'd like to produce a bulk commodity in a container in 2d.
The original LAMMPS insert-commands seem to insert new particles very slowly (I have to wait lots of timesteps, to have all my particles to be inserted), so I tried the LIGGGHTS insert-commands pour/dev and pour/dev/packing.
For both of these insert-commands I need the
- fix particledistribution/discrete command
wich needs the
- fix particletemplate/sphere command
which seems to be available only in 3d.

Is this correct or is there a possibility to use them in 2d?

Thanks in advance,
kind regards

Hey

I've seen a previous post about the error 'too many atom sorting bins', but unfortunately it didn't allow me to solve the problem.

I assume its something to do with my neighbor line, or setting sizes for regions (although I have seen large imported meshes so I don't think it can be the latter. I have tried to find the issue by reading the documentation, but again came across the same error. Attached is my code at the bottom if anyone would be so kind as to have a look?

When I have neighbor 0.05 I have the error 'too many atom sorting bins'. Fine so increase the number...

Dear all,

I cannot find the bug in my script. Please help me, because I don't understand, why there doesn't appear any repulsion of my particels after falling on the ground.

Here is my little script:

dimension 2

atom_style granular
atom_modify map array
boundary m m p
newton off
echo log

communicate single vel yes

units si

region reg block -0.03 0.03 -0.03 0.03 -0.0002 0.0002 units box
create_box 1 reg

neighbor 0.002 bin

neigh_modify delay 0

#Material properties required for new pair styles

Hello,

Probably a really simple question... but when you initially insert a mesh, where does it place it originally before any offset is applied? At the origin of the simulation region?

I am just trying to understand how it inserts so I know that my mesh is placed correctly. I have looked at the fix mesh/gran help file but it doesn't say how it picks the point of reference of the inserted mesh and if the point of reference in the region is indeed 0 0 0.

I used solidworks to create the STL file if this is of any use in answering my question

Thanks

Jay

Hi,
I am doing simulation and printing out temp of granular particles but it displays very high value, I dont understand its meaning. Can anybody guide me?
Value output on screen (in fifth column) :

61000 2360 0.0032032676 0.00055331777 3.8438666e+16 0.001189728
62000 2360 0.0067480441 0.0004580142 7.3734852e+16 0.001189728
63000 2360 0.0094283732 0.00042055652 1.0077762e+17 0.001189728
64000 2360 0.0098094931 0.00042700973 1.047434e+17 0.001189728

I used these commands for computation of temp.

compute T all temp/sphere
and then:

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