LIGGGHTS® - User Forum

Hi ,
I am trying to set up a simulation with multiple spheres clumped together to form rod shape particle.
As I am still very new in LIGGGHTS, I am having dificulties in doing this simulation.

Can someone share example solved exactly as seen in LIGGGHTS Features > Non-spherical particles > Example - pouring a continuous stream of non-spherical particles, where can be seen particles made of 3 spheres stick together.

Thanks in advance.
Kashif

Hello,

Can I have an example of a simulation where both spheres and multispheres are used?
In particular I would like to specify more types of spheres (different diameters) and multispheres (different clusters).

I feel a bit lost when I have to specify the material properties of all the types.
Do I have to specify a set of types for spheres starting from 1 and another set of types starting again from 1?

Hi all.

I'm running a script where I have a mesh/surface shutter that is rotating counterclockwise from a starting angle. I want to unfix this mesh once it reaches a certain angle and I've been trying to think about the best way to do this in LIGGGHTS.

The best idea I had was to track the co-ordinate of a point on the mesh (i.e. a bottom corner, which is one of the co-ordinates I inputted to make the mesh) and use an if statement when this co-ordinate exceeds a certain value.

Hello,

I am having various problems while implementing SPH cases in LIGGGHTS. Firstly, I am not able to include .stl geometries into the fix wall/region/sph command as it does not accept a fix mesh/surface. I then converted the .stl into an ASCII VTK format and tried to introduce it as a region, which was successful. However, implementing this region in fix wall/region/sph is causing problems when it is an open geometry, such as a cylinder with one face open.

Hello, Everyone

I tried to use Washino/Capillary/Viscous in my simulations.
However, I got errors saying: the value of "maxLiquidContent" has to be 0~1.
I checked the cohesion_model_washino_capillary_viscous.h
Seems like the setting of "maxliqduicontent" is the same as "surfaceLiquidContentInitial", which is in unit of %.
Just want to confirm how do I correctly set the maxliquidcontent in this model? for example, should I type 5 for 5%, or 0.05 for 5%?
Many thanks!

Renge

hey guys, i have a similar problem.
Im trying to simulate an underwater slope with a given volume fraction. First I try to generate a normal box of particles and the delete the particles to generate the slope with a restart file.

this is my input data:

#Unterwasserboeschung

atom_style granular
atom_modify map array
boundary f f f
newton off

communicate single vel yes

units si
processors 2 2 1

It appears to be a huge inconvenience if 'fix massflow/mesh' cannot use 'delete_atoms' with 'fix multisphere', as the error shows below:

#########################################################################################
ERROR: Fix massflow/mesh (id massflow): can not use 'delete_atoms' with fix multisphere/* (../fix_massflow_mesh.cpp:304)
#########################################################################################

After I updated LIGGGHTS-PUBLIC to version 3.6.0, my simulation tests cannot run for the following reason:

Hi, everyone

I've been trying to compile LIGGGHTS 3.6.0 on both my mac and centOS by:

cd src
make clean-all
cd STUBS
make clean
cd ..
make serial

However, I kept getting this error message:
mpi_liggghts.h:82:10: error: use of undeclared identifier 'MPI_UNSIGNED_LONG'

I succeeded on compilation of LIGGGHTS 3.4, however I had this problem when trying to compile LIGGGHTS 3.5 and 3.6
Appreciate very much if anyone could help!

Best Regards,
Renge

Hi All, I was faced with the following error:

ERROR on proc 0: Cannot open mesh file filename.stl (../input_mesh_tri.cpp:105)

Please help me for solving it.

Thanks a lot,
Ali