LIGGGHTS® - User Forum

Hello,

I am analyzing particles trajectory off conveyor belt. I have these two fixes in the script;

fix conv all mesh/surface file meshes/conv_200.stl type 4 move 0.0 0.0 0.0 rotate axis 0 1 0 angle 13.5 surface_vel 0.5 0.0 0.0 #Thats the conveyor belt
fix h_pulley all mesh/surface file meshes/head_pulley.stl type 4 move 0.0 0.0 0.0 rotate axis 0 1 0 angle 13.5 curvature 1e-6 #Thats the head-pulley

Hi Everyone,

I am a beginner in Liggghts and want to use Paraview for which I need to generate .pwd type of files from the superquadric (3.8.0) release 7. Any guidance will be very helpful. My system is CENTOS 7.

Thanks,
Sounik

Hi all,

I am using the fix ave/euler command to calculate the stress tensor. Can I specify a region to calculate the stress tensor instead of the whole domain? I do not understand the function of basevolume_region but guess it is not used to define the region for the calculation.

Thanks
Linhan

Dear all,

i want to simulate superquadric particles but can't find a feasible way to visualize my simulation data with paraview. Is there any simple solution that works right now?

Best regards

Tobi

Hi,

Now I'm suffering from particles being in wrong position.

I created the mesh as the container and then pour the particles in the container.

After that I push the particles with the other mesh.

But the problem here is some of the particles are getting out of the container and fall continuously.

The thing is that particles should not fall from the container as expected.

Can anyone guess what is the problem?

By the way, I'm using the m m m boundary.

Hi,

I use the compute multi-sphere command to calculate body position, and later I would like to exert a force on each multi-sphere body depends on their position in vertical space(z direction). This used to work for me in only sphere system. For the multi-sphere system,I use similar syntax like following

compute zp all multisphere property xcm
variable prs atom -20.*c_zp[3]
fix pressure crystal setforce 0.0 0.0 v_prs

hello!

I am trying to see the interaction between a structure and particles by using an external coupling with LIGGGHTS. I modeled a structure by using mesh model. So with move/mesh function, I would like to update the mesh's position and velocity from my code and receive the forces applied by particles to my code.

Is it available for LIGGGHTS to read the position and velocity from variables out of the program?
This option of "linear/variable args" seems to be suitable, but still, don't know how to feed those variables in the input file.

Hi,

I'm starting to play around liggghts library functions (/src/library.cpp) inside my fortran code.

My doubt is whether can I pass a different number of arguments (natoms) in lammps_scatter_atoms than I've got in lammps_scatter_atoms.

To clarify, I'll be handling the collisions in LIGGGHTS and the rest in my code. Is it possible to make the particles inlet inside my code or this has to made in the LIGGGHTS directly?

Thanks in advance.

Hi all, I am trying to set up a simulation where particles are inserted in an extreme of a rectangular pipe. Then, a movile surface should compress the particles (along the z axis). The sript (attached here) runs but few steps later the following error comes up:

ERROR: Mesh (id servo): Mesh elements have been lost / left the domain. Please use 'boundary m m m' or scale/translate/rotate the mesh or change its dynamics (../multi_node_mesh_parallel_I.h:680)

Indeed, when I visualize the case, four or five particles leave the domain.

Hi There,
I am an admin attempting to install liggghts on a linux compute cluster using make mpi.
I have openmpi installed and run the make mpi command whilst in the src folder.
The install seems to begin but then fails with the following error :