LIGGGHTS® - User Forum

I am attempting to run drum mixing simulation of packed granular bed. The trial outputs in two cases of simple cubic and HCP packing are attached with the link below:

Consider a situation in which particles have been packed between two plates and say one of the plate is being moved. The boundary conditions are periodic in the direction of movement of the plate (the plate, an imported stl, is being moved in x direction using a linear style in fix move/mesh and the boundary conditions are periodic in this dimension, but it takes the plate out of the simulation box). Is there any command in liggghts which can help. If not is there any other way to implement it in liggghts ? Please suggest, I am a new user.

I called command insert/pack to insert particles with a constant horizontal velocity(Vx). when particles hit a wall,　the wall started to move and region created by create_box become larger and larger. particles moved out of original region area. I could not understand why reason it cause region box became larger and larger.
Does it means that results of calculation is wrong and some parameters like horizontal velocity, radius of particle etc. should be changed.

Thanks in advance.

Simon

Hi richti83,

I want to calculate the total number of atoms used in simulation. How can I find the function of this purpose ? thanks a lot.
yyu

Does anybody know if I can add hydrogen ion or hydroxide ion in solution to simulate the pH effect on the surface charge of the mineral surface? Thanks

I am trying to analyze the effect of packing style on the granular motion. A particular region needs to be filled by packed bed of specific style (bcc, fcc, hcp).

Is there any way or inbuilt command in LIGGGHTS to handle this task? On the other way, I think it is possible to replace the particle coordinates in dump file with the coordinates (that suits the specific style of packing)
generated by third-party package. But still, if there is a simple way to do the same?

Hello everybody,

Dose anybody know how can we restore a value defined by variable in a simulation (it is scaler defined after the simulation results) and then use the value in a new simulation? I use write_restart to save the simulation but it seems that the value defined by variables can not be saved. I can manually input the variable in the new script but it is time consuming. Any good ideas?

Jeremy

Right now, shape of particle is a sphere. Can user define a shape of particle like cube, ellipsoid etc. if yes, could you please explain how to do it.

Thanks in advance.

Simon

Hello, has anyone successfully been able to calculate and visualize the force chains within a multi-sphere body?

I'm using the "hybrid granular molecular" atom style with a "fix rigid molecule" command, and am curious to see the force within the conglomerations/molecules and how that changes over time, i.e. with contacts.

Hi,

I am trying to simulate the following code, but when I entered dump command xyz(dump("dump*")).many()
It is showing that no dump file specified . Please tell me where it went wrong.

units real
dimension 2
boundary p s p

atom_style atomic
neighbor 2.0 bin
neigh_modify delay 5

# Create Geometry
region boundary block 0 100 0 80 -0.25 0.25 units box
create_box 3 boundary
mass 1 60.1
mass 2 60.1
mass 3 60.1