LIGGGHTS® - User Forum

Hello guys, apologies if the question is repeated here.
I have been trying to simulate two types of particles through inclined surface. I don't want to use `.stl` file to define surface for particles insertion points.

I want to use cylindrical region and insert particles from that region.

When I use the `insert.stl` then it works but when I remove insertion cad and use region with

`fix ins nve_group insert/rate/region seed 32452867 distributiontemplate pdd1 &`

It gives error.

I am using the units microns and
atom_style sphere n
neighbor 0.002 bin
neigh_modify delay 0

with the configuration of the data file below
5 atoms
0 bonds
1 atom types
0 bond types

-0.1 0.1 xlo xhi
-0.1 0.1 ylo yhi
0 0.1 zlo zhi

Atoms # full atom id atom type diameter density xyz(for sphere)

I am trying to fill the spherical particles inside the cubic bed. I have created the geometry using the blender. But no matter how refined the mesh I am creating liggghts is showing mesh error like curvature aspect ratio etc. I see tutorial examples of liggghts, it seems mesh should not be a big issue, but why I am getting this error? Another question is in my mind that whether the blender is good software for creating geometry for DEM purposes?
Which software is more suitable for stl or obj file
Thanks in advance

Hello Community

Hello everyone,

I have a question related to LIGGGHTS.

I am trying to visualize the effect of cohesion in my simulation. Since my particles are not interacting to each other and they are falling to inclined plane one by one. I was hoping to see the effect of cohesion between particles and inclined plane (especially on particles bouncing position) but I couldn't see. That means cohesion model doesn't make any effect on bouncing position.

Right now I am using these commands

Is there a way to determine the total number of multispheres in a simulation? The compute multisphere can provide properties (xcm, vcm, etc.), but it does not give a total count. I am running LIGGGHTS through the Python interface in parallel, and I need to know how many multispheres there are locally on each processor. In library.cpp, there are the lines to access total atoms and local atoms -

if (strcmp(name,"natoms") == 0) return (void *) &lmp->atom->natoms;
if (strcmp(name,"nlocal") == 0) return (void *) &lmp->atom->nlocal;

So, as the title suggests i am struggling with the installation of Liggghts on Ubuntu 20.04 LTS version, i have tried multiple attempts at trying to get this to work but to no avail, the current error message is displayed within the terminal:

Makefile:461: *** 'Could not compile a simple MPI example. Test was done with MPI_INC="" and MPICXX="mpicxx"'. Stop.
make[1]: Leaving directory '/home/dominic/LIGGGHTS-PUBLIC/src/Obj_auto'
make: *** [Makefile:114: auto] Error 2

Hello All,

I have a simple shear case in which fix deform is used to shear the box. Using and not using fix momentum in all three directions did not have any effect on the final results.

When I include the gravity in y -direction for the above shearing case, is it correct to use fix momentum in y-direction also?

Also, could you please let me know when should one "use fix momentum and not" in a CFDEM simulation?

Thank you,
Jagan Mohan.

make[1]: *** No rule to make target '/usr/include/x86_64-linux-gnu/bits/libc-header-start.h', needed by 'compute_erotate.o'. Stop.