LIGGGHTS® - User Forum

Dear community,
I'm modelling powder flow and would like to account for cohesion and adhesion. The LIGGGHTS cohesion modules require
a cohesion energy density defined for each pair of materials. Where do I get this parameter from ? I couldn't find it in literature
Is there a way to get an estimate for the cohesive energy density ? Is there any link between this parameter and Force curve obtained from AFM measurements ?

Best regards,
David

Hi
have two problems. The first one is the ERROR message: Invalid atom style (atom.cpp:343) by using

atom_style hybrid granular molecular

this message occurs despite that I installed the molecule package.
(I use the LIGGGHTS-PUBLIC Version 2.3.8)

My second probleme appears by using the create_atoms command.

create_atoms 1 single -1 0 2 units box
set atom 1 type 1 diameter ${Durchmesser}
fix gravi all gravity 9.81 vector 0.0 0.0 -1

Dear all,

I have a question related to LIGGGHTS. I want to save the simulation run in a specific time (make an initial condition for the final simulation) and start new runs based on this saved simulation. For example, suppose that I have inserted particles and the insertion step is completed, the results are saved and I want to start new runs from this point. How can I accomplish this?

Best regards,
Shahab Golshan

Hello everyone

I do not understand how to decompose a problem correctly in parallel.

for example .... ¿what does this decomposition "# processors 2 2 3"?

thanks.

Hello.

I have some question about the mutual consistency of the damping coefficients for Hertz's contact model.
From doc for gran/hertz/history (I use liggghts-1.5.1) I got:

gamma_n / gamma_t = 1/2 * (Y/G)^(1/2)

From my own solution for Hertz and Mindlin equations I got:

c_n / c_t = (5/6)^(1/2) * 1/2 * (Y/G)^(1/2)

Comparing my solution with liggghts I see that,

gamma_n = c_n
gamma_t = (5/6)^(1/2) * c_t

Hi,

since version 3.0.1 was released and there are some changes (http://www.cfdem.com/node/42), I updated the basic setup tutorial for Ubuntu(>12.04)/Mint(>14) and maybe other distributions. There is jpg and png support for dump image and back again - mpi support. It's a basic install, without additional packages and tools. The syntax highlighting for gedit was updated to LIGGGHTS version 3.x.

My problem is that i want to rotate a solid body around his axis but this body is rotated by an angle of 40° an moved in my testing area. (as you can see in the picture).

Now the command to rotate a body is for example:
fix move all move/mesh mesh cad1 rotate origin 0. 0. 0. axis 0. 0. 1. period 0.05

So my problem is that i can't explain myself how to modify this command. I hope someone can help me.
Thanks

Hi,

I've built LIGGGHTS with the ASPHERE package and was able to generate an ellipsoid particle, but I'm struggling to find how to use a dump command to output data like the shape diameters and the quaternion to define orientation. I'm using "atom_style hybird granular ellipsoid"

Any help anyone could provide would be appreciated, thank you.

Hi all,

I'm trying to setting a variable heat source depending on particle temperature i've read that this is a task that it can be accomplished with the new version of liggghts, so here is my code:

#---------------INIT SECTION------------------------------------------------------------------------