LIGGGHTS® - User Forum

Hi,
I need to insert 8 µm spheres, and have considered an empty margin for the insertion face:
(real) inlet face:

• x= 0
• y_min= -1e-4, y_max=1e-4
• z_min= 0, z_max= 1e-4

particle insertion face:

• x=1.8e-5
• y_min= -8.2e-5, y_max=8.2e-5
• z_min= 1.8e-5, z_max= 8.2e-5

I get ERROR: Fix insert/stream (id ins): insertion volume could not be distributed properly in parallel. Bad decomposition or insertion face extrusion is too small or outside domain (../fix_insert_stream.cpp:551).

Hello, I am working on quantifying the fragmentation of material by breaking bonds. I use liggghts-with-bonds, I would like to quantify how many bonds were broken to obtain the particle size of the rock after being fragmented by compression.
Could you tell me commands to give me information about the status of the bonuses, please?

Hi,
I just noticed, that the limitations for the youngs modulus in src/global_properties.cpp were changed in version 3.8 quite drastically (by two orders of magnitute), but only for the CGS-system. Does anyone know why that happend and if it is of any relevance for the equivalence of simulations done with 3.7 and 3.8?
Thanks in advance

Hi, I installed LIGGGHTS-WITH-BOND then to add the MOLECULA package:
make yes-m or l e c u l e
make g ++
Anyway I get an error:
WARNING: Granular Bond: This is a beta version - be careful! (../bond_gran.cpp:83)
ERROR: Illegal region command (../region.cpp:426)

Does anyone know if the electrostatic EWALD method is implemented in LIGGGHTS? This page suggests it is https://www.cfdem.com/electrostatics however I've been unable to find anything in the documentation to support it.

Thanks,
Thomas

Where can I get detailed information about the " Easo" method?

Thanks

Hello,
As a part of my project, I need to insert particles of different range in different concentration (particle size distribution). How should I enter my code.
Thank you.

Hello everyone.

I am trying to implement the standard JKR cohesion model into LIGGGHTS. I modified the equations as required in normal_force_hertz.h. For speed and efficiency reasons I created an external file (a lookup table), which provides the value of the contact radius based on the overlap distance (deltan). So with the available "deltan" value, I need to access this lookup table and interpolate the corresponding value of the contact radius. As mentioned before, I need this interpolated value of the contact radius in order to ease the calculations in normal_force_hertz.h.

I've used a DEM software, i try to learn the "liggghts", but I 'm still confused about the key word "seed" in fix command , which could not be found a corresponding value or definition in the DEM software. So is there a clear definition or meaning about this key word? Hope helps from you!

Hello
I am doing wall friction test simulation. The procedure is as follow
1. Fill a cylinder with particle
2. Add a constant force of 100 N and move the cylinder against wall with constant velocity
3. While cylinder is moving against the wall the force is constant
4 I want a graph between normal force and shear force on the wall

Can any body help me in this?