LIGGGHTS® - User Forum

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.

My main question here is: should the simulation results be dependent on the values chosen for the neighbor page and one settings?

My neighbor settings are set as follows with the skin set to the diameter of the biggest particle in my simulation, and my particles are uniform or in some cases have a small range of sizes:

neighbor ${maximum_particle_diameter} bin
neigh_modify delay 0 every 1 check yes page 100000 one 2000

Hello LIGGGHTS experts,

I am working in the field of particle dampers and I am very new to the LIGGGHTS world. Therefore, it would be great if I can get some help from the LIGGGHTS community.

I have attached the figure of the Spring-dashpot system, which I am trying to simulate. My question is how I can model the Spring and Dashport, which are connected to the box in LIGGGHTS?

Thank you for your Help.

Hello,

How can I enable torsion torque for a primitive wall? Please see the error below. The ordering works for pair_style, but not for wall/gran. Thanks!

fix wall_z1 all wall/gran model hertz tangential history cohesion sjkr rolling_friction epsd torsionTorque on primitive type 1 zplane 0 # floor
ERROR: Fix wall/gran (id wall_z1): Unknown argument or wrong keyword order: 'primitive' (../fix_wall_gran_base.h:131)

% script, up to error