LIGGGHTS® - User Forum

Hi LIGGGHTS users,
Can LIGGGHTS do simulations of static granular media like slowly sinking of big particle in the static bed of particles etc?
Thanks in advance
Amrita

Hi everybody,
I am getting too much neighbors for my following file.
I am using the fcc lattice, so it will have have co-ordination no 12.
But the output is giving me co-ordination no as 655.
It creates 655 atoms

###### code starts here ###############
units si
boundary s s s
atom_style granular diameter 0.001 density 9000
atom_modify map array sort 0 0.0
newton off
communicate single vel yes

lattice fcc 0.002
region reg block 0 1.6e-2 0 1.0e-2 0 0.006 units box
create_box 1 reg

create_atoms 1 box units box

pair_style gran/hooke/history 1 0
pair_coeff * *

Hi,
I have filled one cylinder with particles and then i want to insert one big particle on the bed of beads. I use lattice command to do this and apply create_atoms single command, but after that i found "nan" values in output screen. I modified the command many ways, but all in vain.. First I poured particles with pour/dev command and then with create_atoms for inserting single particle. Is there any solution?
Thanks,
Ram

Hello everybody,

I'm about to reconstruct the spring and damping forces in a simple 1-particle-simulation (1 particle falling on the ground) and I have a simple understanding problem:

Using the formulas from the doc pair_gran, I am not able to obtain the dumped forces by myself, which are calculated by these (basic) commands (I appended the whole input-skript in a file and in another file I appended an Excel-Calculation of the forces of that moment, when the particle touches the ground for the first time).

hi,

Can i install GPU to ligggghts? How?
Have somebody any experiences with this?

I try to install GPU to ligggts:
- download and install nvidia cuda toolkit
- add directory to PATH and include cuda/lib

but when i start "make -f Makefile.nvidia" i get error: "gb_gpu_memory.cu:67: error: ‘__T11’ has not been declared"

many thanks
jikra

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