LIGGGHTS® - User Forum

Hi all,

I try run a simulation with small particles, for this I use two distributions of particles with radius 0.0001 and 0.00015.
The simulation run fine, but when the particles in contact with the geometry jumps far away beyond the box.

For example, I modify the example "chute_wear" and just change the radius of particles and the results are like i said (
see attachment).

Any idea for help me in this problem?

Regards,
Felipe

Hi all

I'm running a simulation with cohesion model.
I would like to get the value of normal contact force and cohesion force separately, is there anyway to dump the cohesion force or how can i access the variable Fn_coh in the source code?
Thank you for your help!

Best regards

Duy

Hi all
How can I calculate best timestep for my program!?
Thank you

Hallo everybody,

I'm wondering how the contact force between particle and an stl-wall is calculated?

In the pair_gran doc the particle-particle contact force is explained, does it also apply to particle-wall contact?

If yes, what does the parameter m* stands for?

Kind regards
Philipp

Hi all
I have a problem.
When I visualaized my program,I see that 2 particles are stuck together!
and are separated from other particles!
I do not know why!
My program consists of 2800 particles and particles rotate in a ring.
friction=0.7
timstep=0.00001
Please help me
Thank you

Is there a limit to the amount of timesteps that a simulation can be run? Is it possible to run simulations up to, say, 100 billion timesteps?

Hi all
I have a ring that rotates around the Z axis . Is there any other way (except to change period) to determine the rotation rate?
*********
fix movecad1 all move/mesh mesh cad1 rotate origin 0. 0. 0. axis 0. 0.0 5.0 period 3
*********
THANK YOU

Hi everyone,

I tried to model a conical wall with the "fix wall/gran/" command. However, the result shows an error as "unknown primitive wall style". Does anyone know how to model a conical wall or how to modify this? Thank you.

I try to fill a region with insert/pack using four diferent particle radii from the same template. However, if I try to use more processor cores e.g. 24 instead of 10 then there are empty regions where no particles are inserted. This seems to be associated with using more than one particle, since if only one particle size is used then all regions are filled normally without regard of the number of processors.
I attach two screenshots showing the difference. The first using 24 cores and the second using only 10 cores but the same script.

Hello all
I have a problem.
This is part of my input:
fix boxwalls_z1 all wall/gran/hertz/history primitive type 1 zplane -0.025
fix boxwalls_z2 all wall/gran/hertz/history primitive type 1 zplane +0.025
I want to particles have friction together but do not have friction with the
zplans!
How can i ?
Please help me
Thank you