LIGGGHTS® - User Forum

Hi users

I am a new user of the LIGGGHTS, and i work in my resource with this program. I have a questions, How can i install molecular package? I need to work with ellipsoid for my resource, and i have read that others users have created codes for this atom style but the program needs the molecular package. Thanks very much

Dear colleagues,
There are many tools to generate .stl mesh., i. e. FreeCAD, solidworks, G-MESH. Which one goes better with LIGGGHTS?
How do i know if my mesh is good enough or not? Thank you inadvance for your expertise.
Best regards,
ZYan

Hi,

Hi,

I have been trying to simulate particle flow through what is basically a rock impeller, which runs at approximately 1800 rpm. Particle speeds can be up to around 60 m/s, and maybe 40% of particles will fly through both the impeller walls and the outer (static) wall. Both are generated from stl files.

I have tried reducing the timestep down to 1e-7, with no noticeable improvement, and have also tried reducing the mesh spacing in the stl files.

Is there anything else I can do to improve the detection rate?

I have been trying to add a new plasticity contact model to the LIGGGHTS code. I have the formulation down but this model requires I keep track of the plastic deformation between particle-particle and particle-wall contacts. It should work similarly to the shearing array that is present in the code. However, I have been unable to add the array properly.

Hi everyone

I have written a small piece of code that converts the dump file to vtk. It works through cmd/comsole in windows and takes the standard fields in dump file i.e. id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius. A recompilation after modifying the source code can be done if the field are different than specified.

Dear colleagues,
Do you know if it is possible to exclude ( or disable) those particles (i.e. particles in a sellected cube) from the calculation. Thank you in advace for your
help.
Cheers
ZYan

Hello all,

I was trying to install liggghts source code following the steps provided on the web. The first steps run as in the tutorial but I had problem with "Set symbolic link for LIGGGHTS" command.

Here is some commands I used and their outcomes :

which mpirun
/usr/bin/mpirun

which mpic++
/usr/bin/mpic++

mpic++ -v
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)

cd /home/"user"/LIGGGHTS-PUBLIC/src
sudo make clean-all
sudo make make fedora

Hi LIGGGTHS USER, Hi Chris,

as a commercial DEM code user, I have done realistic particle simulation several years ago. However, it's difficult to modify or add new contact model for commercial software. So I want to implement this job with LIGGGHTS. I have few question concerning the proper "atom_style" for rigid body:

Test example: three non-spherical particles drop under gravity. Their initial positions are (0 0 1), (0 0 1.5), (0 0 2.0) receptively.

1) Method 1: only "atom_style sphere" is used.

Hello, So I am running simulations of a simple agitator in a bucket (see agitator pic). I am interested in calculating the torque of a spinning agitator but my results seem odd when I use tangential history on the gran/wall and pair_style fix. When I plot the f_agitator_post[6] (from everything I read, it seems that this would be the torque acting on the agitator body in the z-direction), the values jump between positive and negative 2 N-m (see tangent_history_chart). This result seems rather odd because the blade is only spinning in one direction.