LIGGGHTS® - User Forum

Hi,
Could anybody give us a list of published papers (or thesis) using the LIGGGHTS code ?
Thanks a lot .
Alex

Hi all,

I'm new to Ligggghts and this might seem a little 'out-of-liggghts' question but I thought you might help.

I'm running simulations on a supercomputer provided by my university.

Hey

easy question, I've forgotten how to do, so I thought posting on here might be quicker.

How do I define two different atom types?

Essentially I want to pour atoms in of one type, and define meshes to be the atom style of another.
With one atom type I have never had to previously define types as the following did the job]

region incyl cylinder z 0 0 0.035 0.04 0.13 units box
group nve_group region incyl
fix ins nve_group pour 25000 1 2 region incyl diam uniform 0.001 0.002 dens uniform 1500 1700

with fixes before applied to all for atom properties

Hi,

actually I tried to figure out in the LAMMPS manual, how I could access the kinetic energy of my granular system.
I understood, that LAMMPS is calculating the kinetic energy in a MD sence (ke = 1/2 Kb T).

I wonder if the ke in my thermo-output is calculated like 1/2mv^2 for all particles if I use the LIGGGHTS package?

Thanks in advance,

Sebastian

Hi,
I'm trying to use Kn and Kt instead Young Modulus. I wrote:

pair_style gran/hooke/history/stiffness 3 0
pair_coeff * *
...
fix m9 all property/global kn peratomtypepair 1 5000000
fix m10 all property/global kt peratomtypepair 1 5000000
fix m11 all property/global gamman peratomtypepair 1 0.7
fix m12 all property/global gammat peratomtypepair 1 0.7

But LIGGGHTS crashes without error message.
What I'm missing?

Thanks for any help

Andrea

Hello liggghts-team,

I want to simulate a role(cylinder) that moves linear along the systems X-Axis and it should rotate around its roll-axis.
Is there a way to do this?

1) I tried using 2 fix commands, but as expected only the late fix-command wins.
2) Rotate the role and moving the assembling linear around the role, is not a good alternative, producing wrong results.

Is it possible to script something like this:
even step = linear move
odd step = rotate role

hi, I'm new to this open source DEM code.
I try to find a User's Guide about LIGGGTS to get more information about the code. But it seems that there is only a install guide.

By the way, what's the requirement (or recommended) of computer hardware to use the code?

Thanks for help in advance.

Hi

I am trying to create a time-varying version of the "conveyor" feature of fix/mesh/gran. The most obvious way to do this is to update fix_mesh_gran.cpp every timestep. I have found the "time_depend" variable in fix_move_tri.cpp and other files. It seems to be a flag determining whether the function is time-dependent or not. Adding this to fix_mesh_gran does not seem to work - my programme is supposed to output to screen each timestep, but it doesn't. What else am I missing to make this work?

Hello,

may someone can give me a hint or help me with this.

I am asking for an alternative way to move one stl linear while another one is rotated,
because this does not seem to work:
fix movecad2 all move/mesh/gran linear 0.0 0.0 0.12 cad2 1
fix movecad1 all move/mesh/gran rotate 0.0 0.0 0.10 0.0 1.0 0.0 50. cad1 1

The szene is a rotating cylinder and a particle filled box is moved towards it.

Some ideas?

Thanks
rene

Hi All,

I need to get the list of contact forces for each atom. I am using LIGGGHTS as a library in my C++ code and need a class or function for getting that list. Do you have any comment?

Bests,
Ehsan.