LIGGGHTS® - User Forum

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))

I've been simulating tensile tests of elastic materials to validate my model for some research I'm doing, however I'm finding that I get anisotropy in bond formation where I get layers that do not bond well, even with different seeds for bond formation and insert/pack random particle insertion.

Hello!,

I opened VTK files for sphere packing in Paraview, and applied Glyph filter. However, I can't adjust the theta and phi resolutions as in Sphere Source. How can I increase the resolution of the geometry? After saving as STL file, I found its resolution is very poor.

Hello everyone,

I have a case where particle sizes stretch across an order of magnitude. Do you have any strategies for realizing efficient contact detection in such a scenario? How do you size the bins for this kind of case?

Any input would be greatly appreciated!

Hello,
I am trying to create multi sphere parcels included 9 spheres. and I used the following command:
fix pts1 all particletemplate/multisphere 15485863 atom_type 1 density constant 2500 nspheres 9 ntry 1000000 spheres file data/stone1.multisphere scale 0.001 type 1
If I want to have 200 parcels, should I create manually 200 particle parameters (positions, radii) in the data/stone1.multisphere file?
is there any way to create 200 multishperes? because the shape of all them are similar.