LIGGGHTS® - User Forum

Hello,

I have a planar x - wall which I want to represent with spherical particles. I wrote the following lines:

Hello People,

i am a newbie in the LIGGGHTS. I am trying to calculate kinetic energy of two movie particle of same material type. Two Particle has the diameters of 3 and 5 micrometer. I can't match the same value down there with hand calculation for KinEng.

Memory usage per processor = 1128.1 Mbytes
Step Atoms Volume KinEng
0 2 125001.5 0
1 2 125001.5 3979.3507
2 2 125001.5 3979.3507

Hello all,

I am a student who is very new to using LIGGGHTS, but I'm building a simulation of packed particle flow over a surface to study abrasion of that surface. Since the surface is uneven, the flow of particles isn't always laminar, and in some regions the particles may flow faster than in others. I'm wondering if anyone can tell me how to determine when the simulation has reached convergence - in other words, how do I determine how many timesteps are "enough?"

Hello!

I have a series of commands I would like to execute in an increasing fashion. For example:

1. [ Run 10 timesteps, set velocity of particles = 0 ] * 100
2. [ Run 100 timesteps, set velocity of particles = 0 ] * 100
3. [ Run 1000 timesteps, set velocity of particles = 0 ] * 100
4. [ Run 10000 timesteps, set velocity of particles = 0 ] * 100
etc.

Hello,

I have a LIGGGHTS model with a fix heat/gran/conduction. I want to output the conduction contact area information using the dump command. The following properties are mentioned in the online documentation - https://www.cfdem.com/media/DEM/docu/fix_heat_gran_conduction.html

Hello Everyone,

I am modeling the soil-structure interaction, in which the structural material is represented by STL wall and is force controlled in x-direction and displacement controlled in y-direction. But I found once the STL wall is inserted as servo-wall, all directions of this mesh are force controlled. It seems like the mixed control (force and displacement) is not allowed to be exerted on one mesh in different directions. Is there any command I miss for this aim? Or do you have any suggestions for my problem?

Many thanks,

Shw

Hi
I would like to find the Maximum z coordinate of particles pile in a region so i tried using
compute zMax all reduce/region region-Id max z
variable zmax equal c_zMax
print "Height of pile = ${zmax}"
i tried by placing run 0 also and giving compute id in thermo style and update_on_run_end also in compute id and how many times i tried it showing me same error
"compute in variable between runs is not current. try using update_on_run_end"
Can anyone help me with this problem
Regards,
Kavya

Hi,

I can not find the script that integrates all the forces acting on each particle and calculates the accelerated velocity.
Any one can give me some clues, very appreciate!

Dear Community

Hi, I am doing simulation in rotating drum.
My rotating drum rotates for 60 sec and per rotation is defined as 4 sec.
i.e I am going to have total 15 rotaions.

Right now I am saving whole simulation in a single folder.

For some specific tasks, I need information from each rotation.

Is it possible to save dump files based on each rotaion?
e.g. : for 15 rotations, I would like to have 15 folders with corresponding files from each rotation.

Any help would be appreciated.