LIGGGHTS® - User Forum

Hello.
How to calculate the pressure and shear stress on a triangles of the mesh?
Is it the integral of the contact forces averaged by triangle's area?
Thanks.

Hi,
Is there a way to find total volume occupied by particles in simulation region during the run?
Thanks in advance,
Ram

Hi,

I'm doing some work relevant to the cohesion force. I'm confused with the cohesion model in LIGGGHTS. Could someone tell me what model and equations are used in the cohesion force in LIGGGHTS and what source files are implementing this model?

Thanks!

Jerry

Hello

I am having a problem installing LIGGGHTS... a very strange error...

I have used git to pull LIGGGHTS, but when compiling I get a whole list of errors going...
[root@Jay src]# make fedora
grep: cfd_regionmodel_*.h: No such file or directory
make[1]: Entering directory `/home/Jay/LIGGGHTS/myliggghts/src/Obj_fedora'
Makefile:93: region_cone.d: No such file or directory
Makefile:93: improper.d: No such file or directory
Makefile:93: ewald.d: No such file or directory
Makefile:93: fix_wall_gran_hooke.d: No such file or dir....
etc etc....

Hi
I have tried to run Chute_wear example but because of another problem (syntax error) I could not use the normal 3 line commands to change dump file to VTKs.so I did some changes inside the input file to outputs directly vtk files (instead of dump file) . after visualization with Paraview I see a Chute which in animation some moving triangles appear on the surface .so I doubt if it is the real simulation or I am missing something like some particles which I see just affect of them on the surface (without seeing themselves).

Hello,

I'm new in LIGGGHTS and would like to have a look at the input skript of "Particle segregation in a slot geometry".
Where can I obtain it, because I think it doesn't exist in the normal examples-folder, does it?

Cheers

I've done a simulation with three thousand granular particles in a container with a blade stirring them around. See video on the URL below:
https://docs.google.com/leaf?id=0B2EIcnb16wvuZWRmZWRiYTktMGQ4OS00OWMzLTk...

If you look closely, you see that some of the particle's got a "popping" behaviour, it's like small explosions shooting away some of the particles. What am I doing wrong?

Dear Liggghts users,

I have difficulties in defining an additional force due to a couette flow. Therefor I want to add a force depending on the atom position. I define a per atom variable "b" and I want to refer to it as "v_b" in the fix addforce.

I guess I didn't got the idea how to use per atom variables within fixes like addforce.
I attached a simple input file in which I summarized, what I have already tried.

Maybe someone can show me a working example of an addforce/setforce fix with per atom force values.

With kind regards,
Thomas Wagner.

Hi,

I would like to calculate each particle kinetic energy, potential energy (gravity) and rotational energy to total energy

please give me advice.

Dump file is x y z ... but I have to calulate them or just after simulation

extra term kinetic, rotational, potential (gravity) and total (each)

Thank you

Hi,
I'm trying to set a volume filled with particles to use and re-use after.
My questions are:
1) What is the faster insertion method to fill a volume until the level I want?
I'm trying with ins pour/dev but I have to wait for the filling (and some time I have less insertion than wanted); with lattice I have to wait the KinEn decrease (and it doesn't respect the level I want). pour/dev/packing could help me?