LIGGGHTS® - User Forum

Hi everybody,
Could you please tell me why I am getting following error to the code attached below.
ERROR on proc 0: Neighbor list overflow, boost neigh_modify one or page
thanks in advance.
Samantaray

#code starts here

units si
boundary s s s
atom_style granular
atom_modify sort 0 0.0
newton off
communicate single vel yes

lattice fcc 0.0352 orient x 1 0 0 orient y 0 1 0 orient z 0 0 1 origin 0 0 0
region reg block 0 16.0 0 10.0 0 28.28427
create_box 1 reg

create_atoms 1 box

Hi all,

I'm not sure if this is a real bug, or a user error ;-) But here we go... I'm running a simulation using a hybrid granular/molecular pair style with some simple aggregates of non-overlapping spheres. The aggregates are allowed to settle in a frictional box, and this all works fine. I then start to "wiggle" the floor, and it works fine for a while, and then crashes with the following segfault:

Hi,
We have performed experiments of silo containing glass beads of 2mm in diameter. We used 600gm of glass beads. Using LIGGGHTS, when we pour glass beads of same parameters used in experiment then it is impossible to pour even 200gm of beads in 4 times longer cylinder than used in experiment. Is there any solution for it? We want to use same size of cylinder and beads as we performed in experiment. Why liggghts uses more volume to occupy the same mass of beads?
Thanks
Ram

Hi,
first i'm sorry for my bad english.

So my problem is:

I have an stl file(it's cylinder). I imported it to liggghts and i get it rotation(it's OK). In paraView i see ratation cylinder, but i can't show some vector of rotation. What i must add to source code for it.

many thanks.

Jikra

hi everybody,
can you tell me what are the default values of diameter and density in the atom_style granular. It is definitely not 1m and 1kg/m3 in si units. It is not mentioned in the manual.
thanking you,
Samantaray

Hi everybody,
I am recently running the in.chute_wear without any modification. It is generating the vtk files and the dump file without the velocity. It shows the following error while running on the screen.

WARNING: You are using the wear model, which is currently in beta mode!
WARNING: Dump mesh/gran/VTK contains a mesh with no velocity allocated, will not dump velocity

Needs your valuable suggestions.

thanking you
Samantaray

I have just got myself a new 16-core computer and am trying to install LIGGGHTS. I remember that the installation wasn't easy on my old machine, and come up with a pretty similar problem. Guess this is more a linux than LIGGGHTS question but any help would be great. It cannot find files again such as

Makefile:93: neigh_full.d: No such file or directory

but notice on the end the error...
mpic++ -g -O -fPIC -DLAMMPS_GZIP -DMPICH_IGNORE_CXX_SEEK -DFFT_NONE -M fix_aveforce.cpp > fix_aveforce.d
fix_aveforce.cpp:14:17: fatal error: mpi.h: No such file or directory

I have been running many simulations with a Lattice of granular particles with different CAD meshes interacting with them. There has been one major problem that i have not been able to figure out. When my timestep is any higher then 10^-7 gravity will pull the particles right through the bottom ZWall for no apparent reason. This results in the loss of all my particles after a short period of time. And they don't just fall out of the simulation, when they hit the bottom zwall the entire row of particles just disappears.

Greetings. I am attempting to run a simple compaction program of particles in a cylinder. I seem to get a successful packing of particles but they do not interact with the topwall as it moves down in the z direction. Using the cohesion and compression examples as templates, I have the following code:

#Contact model example

dimension 3
atom_style granular #diameter, density, angular velocity
atom_modify map array #processor stores lookup table of length N, N atoms. fast but limited by memory
boundary f f f #fixed boundaries in 3 dimensions

I am trying to achieve an adhesive force which is higher when two particles crash with higher velocity.
My idea was to change gamma_n. Therefor I want to use the Hertz/history/stiffness model. By looking at the equations I noticed that the equations for gamman and gammat looks different from Hertz/history because they don't use Sn and St.
Now I am not quiet sure how to calculate gamma_n and gamma_t.
It would be nice to get a short advice. Thanks.