LIGGGHTS® - User Forum

hi,
i am working on finding the porosity of soil , in that
my volume of the atom or grain changes at certain
timestep. i want to know how to compute the changing
volume in liggghts ?
thanks in advance,
Dixon

I am experimenting with Amazon EC2 to see if I can get some significant wins in LIGGGHTS running time. I've tried a variety of datasets, and I seem to be encountering some sort of slow down beyond 24 CPUs.

My bigger test dataset I'm running is conveyor a simulation. At the end of the 10 second run, there are around 200k particles. The path the particles travel is quite narrow, but oblique, meaning the simulation is highly sensitive to processor partitioning because there are large empty spaces in the simulation box

hi,
i am working on porosity of the soil sample. i have attached the input script with this .
Please help me with this error ERROR: Fix insert/pack (id ins): unknown keyword (fix_insert_pack.cpp:106).

Hi,
I faced a weird problem in my simulation and it is that when I use "gran/hertz/history" as a pair_style my simulation work precisely, but when change the pair_style to "gran/hertz/history cohesion sjkr" my simulation does not work and it leads to the following messages repeatedly.

"touching neighbour atoms found, growing contact history"

I would appreciate it if anyone help me to solve this problem.

Sincerely,
Rasoul

Dears,
I can compile liggghts with gpu packages and I think it works but I can't compile it with user-cuda.
After the compiling of liblammpscuda.a in lib directory, if I try "make machine" I obtain this error:

pair_gran_hooke_cuda.cpp: In member function ‘void LAMMPS_NS::PairGranHookeCuda::allocate()’:
pair_gran_hooke_cuda.cpp:95:39: error: ‘kn’ was not declared in this scope
pair_gran_hooke_cuda.cpp:96:39: error: ‘kt’ was not declared in this scope
pair_gran_hooke_cuda.cpp:97:39: error: ‘gamman’ was not declared in this scope


Hi
how can I fix the problem below?

ERROR: Fix wall/gran/hooke/history (id plate_wall): Fix wall/gran style and pair/gran style have to match, you have to define the wall after the pair style (fix_wall_gran.cpp:251)

thanks so much for your good commands.
Regards mozhgan

Hi
H worte a an example but when I run it this error has apeared

ERROR on proc 0: Cannot open dump file (dump.cpp:392)
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.

Hi Chris,

as the command "region ID mest/tet xx.vtk ..." needs a volume legacy VTK file. What I am really confused is that, what is a real legacy vtk mesh that LIGGGHTS supports? And how to make/convert STL mesh to this type of mesh?

Importing STL file into paraview, and save as Legacy VTK, but it is

# vtk DataFile Version 3.0

and using gmsh -2 xxx.stl -o xxx.vtk, it's

hi
I run some of the examples of liggghts yesterday but today I can't run them and here is the command and the error .

saeed@ubuntu:~$ ~/Documents/LIGGGHTS-PUBLIC/src/lmp_openmpi < in.movingMeshGran
bash: in.movingMeshGran: No such file or directory

thanks so much

I am using LIGGGHTS but it uses only one processor for computing. I have installed LIGGGHTS by following http://cfdem.dcs-computing.com/?q=node/1789

None of the combination like processors 1 2 1 or processors 2 1 2 works...

Don't know whether LIGGGHTS is not multi-processor because no processor settings were made during compilation. Do I need to install LIGGGHTS with some added settings or feature can be added later.