LIGGGHTS® - Developer Forum

Hello everyone,

I have a question about linking LIGGGHTS with other tools like PETSc or establishing a link between LIGGGHTS and VTK?

Hello. I am working on the effect of magnetic force on the particle compaction process. I am using the following Github repository for the implementation of magnetic force:TJLeps/LIGGGHTSwMAGNETICS: official release of the LIGGGHTS® DEM software, by DCS Computing GmbH. For further info, forums, and bug reports, please visit which takes into account the mutual dipole interaction of the particles. In my simulation, I am using superquadric particles. The case runs okay in a single processor, but it does not run in multiple processors.

Hi,
I need help understanding how the fix commands work. Specifically, when you assign a value to a fix variable of a particle, should the index of the particle be its global ID (tag) or local ID (index in the code)? For example:

...
double *heatSource = fix_heatSource->vector_atom;
heatSource[i] = ...;
...

In this case, I need to know if i refers to the global ID or the local index, and whether it starts from 0 or 1. I couldn't find this and need to know to be sure about my algorithm.

I am a beginner in using LIGGGHTS and I am currently working on calculating the fabric tensor for my simulations. I noticed that LAMMPS has a dedicated compute fabric command for this purpose (https://docs.lammps.org/compute_fabric.html). However, it seems that LIGGGHTS does not have a similar command.

Could anyone please advise on how to calculate the fabric tensor in LIGGGHTS? Are there specific procedures or workarounds available for this?

Thank you in advance for your assistance.

Hello everyone,

Hello everyone,

I have a question about the problem statement I'm currently working on.
I'm trying to model polymer curing respect to time. Thus, viscosity has to change with time.

Is there a way to put time-dependent viscosity or have viscosity change over time?

So far, I just defined viscosity using 'dragfoce' command using Schiller_Naumann viscosity 0.05.

Any help would be appreciate.

Thanks in advanced!

Hello all!

I wanted to check if anyone has implemented Archards wear model in Liggghts and would be willing to share the code with me?
As far as i can see, there is only a Finnie model present.
Br

Hi, I would like to understand better how liggghts work. For this purpose I look through the source code. I would like to dig into the simplest form of dynamic equations "ma = F". Please indicate the appropriate files.
Regards!

Dear all,
I want to develop a contact model for LIGGGHTS, and the stiffness calculation in this model requires the use of fluid parameters such as fluid velocity and pressure from Computational Fluid Dynamics (CFD). How can I achieve this?
LW LI

I have been trying run the command "liggghts -in input.liggghts". However, I'm getting this error:
(1)ERROR: Mesh Silo: The minimum angle of mesh element 0 (line 2) is lower than the specified curvature. Increase mesh quality or decrease curvature (currently 0256235)

(2)ERROR on proc 0: Fix mesh: Bad mesh, cannot continue. You can try setting 'curvature' to 1e-5 or lower or use 'curvature_tolerant yes'