LIGGGHTS® - User Forum

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.

I have been using fix insert/stream to add particles into a simulation through an insertion face. However, the specified particle rate is not obtained if I set a high value of particle rate and a low value for the inflow velocity. I presume the absolute limit of this would be when the spheres are tightly packed, but when I visualise the inlet box using the correct particle size in paraview (glyph), the particles are well spaced out. Can anyone explain what is happening and what is the limiting criteria for correct particle rates to be achieved?

Many thanks!

I'm trying to initialize a simulation with a particle size distribution, created using particledistribution/discrete -> insert/pack, then grown using adapt to increase the volume fraction to 40%. If I try to run the simulation multithreaded, I get MPI faults, and when I run it single threaded I get a segmentation fault. Previously, when using a single particle size, I used the 'scale no' option and had no problems. Has anyone else had trouble with fix adapt 'scale yes'?