LIGGGHTS® - User Forum

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?

Hi all,
I want to create two particles with two different id using the following command
create_atoms 1 single 0.95 0.4 0.5
set atom 1 type 1 diameter 0.02 density 2500 vx 2 vy 0 vz 0
create_atoms 2 single 0.99 0.4 0.5
set atom 1 type 2 diameter 0.02 density 2500 vx 0 vy 0 vz 0

but when I trying to compile the script file it says
ERROR: Invalid atom type in create_atoms command (../create_atoms.cpp:102)

Can anyone please enlighten me that waht I am doing wrong?

Thanks and regards,
Sourav

Hello
I am doing compression test simulation and I have the initial position of the particle. I want to read the particle data from file and give it to liggghts for further DEM simulation.
1. how can I read it. (command for it)
2. what is the file format that liggghts accepts.