LIGGGHTS® - User Forum

Hi everyone

I'm trying to run a model that includes the multicontact model by Brodu et. al. (2015), in a cluster of my university.
In clueter it is installed LIGGGHTS 3.8.0 with Singularity.
The problem is that model do not run in cluster, but in my laptop it works. So I want to ask you if the multicontact model is not available to run in clusters, or is necessary to install something additional to run. The problem seams the MPI comunication doesn't work well with this model in cluster.

Any commentary could help me so much

Best regards.

Hi,

Hello LIGGGHTS Experts,

I wonder if can I prepare simple strain of a cylindrical metal sample in the LIGGGHTS program?
I tried to create some sample using multisphere. I'm attaching my file. Do I get one solid from these few points(atoms)? In what other way can I prepare the multisphere input file? Should I provide points manually? Should I fill the whole area of the figure with atoms? How to prepare such a file?

Hi,

I was trying to calculate the six-component from the stress tensor using fix ave/euler command. The dump looks like this for two cells:

SCALARS pressure float 1
LOOKUP_TABLE default
18.087371
14.514210
-0.000000
-0.000000
-0.000000
-0.000000
17.008131
10.089578
-0.000000
-0.000000
-0.000000
-0.000000

As ave/euler gives the trace of the stress tensor, how can I calculate the Stress tensor with six components?

Thanks,
Sounik

Hi all,

I am facing a strange problem. In my simulation, I use:

"group fines id 1942 753 976 1048 3765 5788......" (up to 1000+ particle ids)
"delete_atoms group fines compress no"

Hi all,

In my simulation, I have two particle size, namely small particles and big particles. Now I need to delete 10% of the small particles in my calculation region, does anyone know which command do I need to use?

Best regards,
Rachel

hello,

I was used to perform simulations using 3 different meshes, one of them is an auger, and the simulations were running normally, but when I extended the length of the auger I was using, the particles started penetrating the auger and filling it from inside. knowing that I kept the same input script I was using before except for importing this new mesh which has the same element size as the old one.

Please find attached two pictures of the two cases, hoping to have any help from anyone.

best wishes,

hello,

I am trying to run a simulation introducing cohesive model, but I am getting the following error:

Hi Everyone,

I wanted to compute atom properties and then dump them in a .vtk file. However, I cannot see them printed. Here are my commands:

compute ins all property/atom id type xs ys zs fx fy fz # Calculation of atom attributes
dump dmp all custom/vtk ${writeOutEvery} post_hl1_100kpa/dump*.superq.vtk c_ins

The error is " ERROR: Dump particle fix does not compute per-atom info (../dump_particle.cpp:594)"

If someone can help with this, I will be very grateful.

Sincerely,
Sounik

Hello,
I have a small cluster of computers that I would like to run DOEs on.
On my machine I call liggghts with the partition flag

mpirun -n 10 liggghts -in DOE.liggghts -partition 10x1

but when trying on the small cluster

mpirun -n 20 -hostfile my_hosts.txt liggghts -in DOE.liggghts 20x1

I get an error indicating that liggghts can not read my input file
(ERROR on proc 4: Cannot open input script DOE.liggghts (../lammps.cpp:442))