LIGGGHTS® - User Forum

Hello everybody,
I'm trying to run an example of cohesive force model of washino/capillary/viscous. When I run this script (as below) the memory usage of the computer is increased illogically so that the run is dead. I decreased the amount of particles but it doesn't solve the problem. May you please help me to know what's the reason and what I can do to fix it?
Thank you

the input script is:

#Contact model example

atom_style granular
atom_modify map array

boundary m m m
newton off

communicate single vel yes

units si

Hey,

I got a question about implementating a value in CFDEM Ligghts.

How do I implement a time-variable value, which shall be variable at every time step?

Is this a possible way to realize my question?
Csurface = fix_Csurface --> vector_atom
vector_atom = Csurface
fix_Csurface = NULL

Thanks for your helpful minds :)

Hello everybody,

I want to simulate a belt conveyor which also rotates around a defined axis.
Normaly I used this command to give the surface of the belt velocity components

fix cv1 all mesh/surface/stress file belt_1.stl type 3 scale 0.001 surface_vel ${beltvX} ${beltvY} ${beltvZ}

Then I want ro rotate this mesh with following command

fix rotatecv1 all move/mesh mesh cv1 rotate origin 0.0 698.8 0.0 axis 0.0 0.0 1.0 period ${time1}

Dear all,
hello,
I'm new on LIGGGHTS so please forgive me if the question is stupid.
I was running the cohesive example of LIGGGHTS. When I changed the cohesive force as washino/capillary/viscous I received this error: "ERROR: Could not locate a fix/property storing value(s) for surfaceLiquidContentInitial as requested by cohesion_model washino/capillary/viscous. (../modify_liggghts.cpp:411)"

could you please help me to fix this?
Thank you in advance

the in.cohesion file is as:

#Contact model example

Hi,

I am new user of Liggghts and trying to simulation particles in micro units. However, when I insert particle, the fix wall/gran command does not work and the region keeps on increasing with the particle movement.

Can somebody tell me how to overcome this problem?

Thanks,
Subin

Hi,

I want to plant the mesh which have charge on it and interact with particles.
But by fix wall/gran, there is only pair_style for granular is supported.
How can I use another pair_style (e.g lj/coul from LAMMMPS) to fix the wall?

And another question is that when I put the wall by fix wall/gran, sometimes particles are stick to the mesh(wall).
Do you guys know why this happened?

Hi,

I an new to LIGGGHTS and trying to figure out how to create an if loop. I looked at the documentation, but not sure how to proceed.
Here is my current code, not sure if this works.

label shearing1
variable xpos
variable strain_inc equal 0.0
variable max_height equal 0.0377

if ${xpos} < ${max_height}*0.01
#if ${xpos} < ${max_height}*.0025+${strain_inc} then

fix move all move/mesh cad1 linear 1e-04 0.0 0.0
fix move all move botwall linear 1e-04 0.0 0.0

Dear all,

I am using Hertz contact model in my simulation. In hertz contact model tutorial document there has given the normal overlap calculation system but for the calculating the total force I need to take account the tangential force. That's why I need to learn the tangential displacement of the particle. It would be a great help and highly appreciatable if anybody help me to get the calculation of tangential displacement for contact model Hertz. Thanks in advance.

Hi everyone,
I am trying to simulate sintering process of dense packed spheres in a cylinder or a cubic. I've got laws of force between two spheres, but how can I modify the forces between the spheres to apply DEM into my project?
Thank you!

Cheers,
Guo