LIGGGHTS® - User Forum

Hello all,

I am trying to simulate flow of particles from a hopper/silo. I keep getting the error stating that there's too many neighbor bins. I have look through a few forums and cant seem to find the solution.

I have set my neighbor bin size to 0.0029, which is 2 times the largest radius of my particles( 2*r_max). I have tried changing the young modulus of particles but still get the same error.

Hi,
I am unclear about the forces that we save in dump file as `fy` , `fz` and `fx'.

Are they contact forces of each particle?

If not, is there a way to save contact forces for each particles?
Any help would be appreciated.
Thank you

Hi Guys

Please refer to the attached input script.
The first 63 lines define the attributes of the simulation thereafter the rest of the input file just consists of moving the mesh based on results I attained from my Matlab simulations. The simulation runs for only about 0.589 seconds, however the full simulation should be 30 seconds.

If I remove all the movement of the mesh the simulation time runs without giving any issues.
The below is the last part of the terminal output.

Hi Guys

Please refer to my attached input file.
I am struggling to understand why I am getting the error "Too many atom sorting bins"
Can someone please assist?

MM

hello,
how can fix adapt command be used for superquadric particles? can some one please help?
thanks in advance,
narayani

Hi Guys

I am trying to use the rotate/variable command as per the below implementation.

fix move2 all move/mesh mesh cad rotate/variable origin 0. 0. 0. axis 1. 0. 0. omega 1

I get the following error when trying to execute my code.

ERROR: Variable name 1 for fix move/mesh rotate/variable does not exist (../mesh_mover_rotation.cpp:174)
(../mesh_mover_rotation.cpp:174)

Can someone please assist with the issue at hand?

How can I get a particle velocity profile across a channel? Is there any specific command?

Hi,

I am working with the EEPA/Edinburgh contact model and due to the lack of doc something is unclear to me.

There are two input stiffnesses called CoeffAdhesionStiffness and UnloadingStiffness. I was unable to exactly determine what the value of the CoeffAdhesionStiffness (kn2kc) should be as it is not used the same way in the original work by Morrissey. In the code it is used to multiply with the loading stiffness to get the adhesion stiffness:

k_adh = kn2kc[itype][jtype] * kn

Hi Guys

This is just my baby steps for a more complex model which I would like to simulate.

I am trying to move a mesh translationally and rotationally at the same time.
Currently I am using the chute_wear model to achieve this.

The code that I am using is shown below, only the rotational movement is being produced.
How can I achieve the motion?

fix move all move/mesh mesh cad wiggle amplitude -0.01 0. 0. period 0.02
fix move all move/mesh mesh cad rotate origin 0. 0. 0. axis 0. 0. 0.1 period 0.05

Hello everyone!
I have a problem with compiling a script in LIGGGHTS due to problems with STL file. I have tried many CADs, such as SolidWorks, Blender, Salome, but all the constructions can't be compiled with an error "Bad mesh, Can't continue".
It works well in Aspherix by using element_exclusion_list command due to excluding one triangle. However, in LIGGGHTS I can't fix this problem.