LIGGGHTS® - User Forum

Hello everyone,

I have a question related to LIGGGHTS.

I am trying to visualize the effect of cohesion in my simulation. Since my particles are not interacting to each other and they are falling to inclined plane one by one. I was hoping to see the effect of cohesion between particles and inclined plane (especially on particles bouncing position) but I couldn't see. That means cohesion model doesn't make any effect on bouncing position.

Right now I am using these commands

Is there a way to determine the total number of multispheres in a simulation? The compute multisphere can provide properties (xcm, vcm, etc.), but it does not give a total count. I am running LIGGGHTS through the Python interface in parallel, and I need to know how many multispheres there are locally on each processor. In library.cpp, there are the lines to access total atoms and local atoms -

if (strcmp(name,"natoms") == 0) return (void *) &lmp->atom->natoms;
if (strcmp(name,"nlocal") == 0) return (void *) &lmp->atom->nlocal;

So, as the title suggests i am struggling with the installation of Liggghts on Ubuntu 20.04 LTS version, i have tried multiple attempts at trying to get this to work but to no avail, the current error message is displayed within the terminal:

Makefile:461: *** 'Could not compile a simple MPI example. Test was done with MPI_INC="" and MPICXX="mpicxx"'. Stop.
make[1]: Leaving directory '/home/dominic/LIGGGHTS-PUBLIC/src/Obj_auto'
make: *** [Makefile:114: auto] Error 2

Hello All,

I have a simple shear case in which fix deform is used to shear the box. Using and not using fix momentum in all three directions did not have any effect on the final results.

When I include the gravity in y -direction for the above shearing case, is it correct to use fix momentum in y-direction also?

Also, could you please let me know when should one "use fix momentum and not" in a CFDEM simulation?

Thank you,
Jagan Mohan.

make[1]: *** No rule to make target '/usr/include/x86_64-linux-gnu/bits/libc-header-start.h', needed by 'compute_erotate.o'. Stop.

Hi ,
I am new in LIGGGHTS. I have tried melting of Nanoparticles in LAMMPS and would like to try it in LIGGGHTS.
I am trying to simulate multi material particles and their melting.
I am not sure how to do it, or in other words which sample case should be ideal to start with. Any Suggestion is appreciated.

Thanks

Nik

I'm inserting superquadric particles in a closed box. I want to achieve different volume fractions samples.

First, I tried insert/stream command but I couldn't control volume fraction with it.

Second, I tried insert/pack and insert/region/rate but only low volume fraction can be achieved with both methods even with very high maxattempt values.

Hi Everyone,

I'm pretty new to liggghts and having trouble on understanding and finding out some of the terms such as what is KinEng and rke in the terminal or liggghts log? (where can i find this info?)

I'm currently building DEM granular model with lattice model. and turns out that for some reason the KinEng & rke return as -Nan. during the run.

It is suspected that due to overlapping integration between lattice section and "fix integr all nve/sphere" (line64).

Please help

thank you in advance

code:

Hi all !

I am a new LIGGGHTS user and followed EngineerDo's tutorial for the silo particle dimension (https://www.youtube.com/watch?v=bCfCpjNuSVQ).

I used his code and tried to modify it for my problem, i.e. the generation of a powder bed particle for Selective Laser Melting. I created my substrate, which consists of a rectangular box of 0.5x0.3x0.3 (L,w,h, all in mm), and a blade which should spread the particles on the substrate after they fall from the insertion face.

Hi All, I an using insert/stream to insert particles from a plane. I have tried inserting particles of different sizes in turn by using two insert/stream, namely inserting one size first, unfixing ins, and then the other ins, it didn't work. Can anyone give any advice?