LIGGGHTS® - User Forum

Hi,

I am trying to simulate shear flow of soft particles with a given pair interaction. I have a periodic box. Is there a way to implement Lee's Edwards boundary in the gradient direction ?

Lee's Edwards Boundary condition : influence of shear on the periodic images is taken into account by shifting the periodic images according to the bulk shear rate.

Thanks,
Lavanya

hi everybody,
I obtained Neighbor list builds = 3405 on screen
for the following parameters.
neighbor 0.001 bin
neigh_modify delay 0
timestep 1.0e-4
run 1
run 40000 upto

My question is for 40,000 timesteps, I would expect to get 40,000 neighbor list builds from neigh_modify command for delay 0.
Thank you in advance for the reply.
regards,
Samantaray

hello everyone,
I feel confused with some questions on liggghts,

#1. what is the largest number of particles can be simulated in liggghts? depend on the operating system?

#2. when particles contact with wall for a long time,. for example, when many particles were dumped into a container which was imported with STL file, the wear quantity of the all the walls of the geometry became negative infinity(-6E+6) after a long time's run. So if I want to calculate the wear quantity of an immersed surface, I have to import the immersed surface seperately?

Looking forward to your reply

Hi all:

I am completely new to this software. I want to start knowing about LIGGGHTS(DEM). My work is about packing of the sphere under gravitational force based on the work of Cundall (the one who creates Discrete element method).

I am familiar with the knowledge of the DEM (honestly, it is not so hard), but about LIGGGHTS, I dont know anything.

I already installed the software in UBUNTU. I run the example of the packing. One log file has been appeared after running, but honestly I dont know what it is.

I installed paraview viewer, python and ...

Hi!

I am new with linux,

I have a machine with 8 Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz processors.

I am using the following command for multi processor simulation in liggghts.

mpirun -np 8 liggghts < in.rot_chute

The program is running good for sometime after which the systems reboots in itself.

I know that it is not directly related to liggghts, but, it would be great if you could give me some indication about the source of problem. I also tried with 6 processors with same problem.

I apologize in advance for not knowing how to do this -- I would imagine this is pretty simple for someone who knows what they are doing (this excludes me, apparently):

I am trying to develop a sintering interaction (pair_gran_sinter.cpp) for LIGGGHTS 1.4.6, and I need to ensure that it is conserving particle volume as the particles sinter together (see movie below for example). To do this, I need to store an array of initial particle sizes (radii) such that it is available to pair_gran_sinter.cpp for subsequent volume and updated radius calculations.

I installed LIGGGHTS in my local LIGGGHTS directory (myliggghts).
step 1 git clone git://cfdem.git.sourceforge.net/gitroot/cfdem/liggghts myliggghts
My system is Ubuntu.
But in the /src directory, when type "make fedora" ,
make[1]: Entering directory `/home/cheng/LIGGGHTS/myliggghts/src/Obj_fedora'
Makefile:93: angle_charmm.d: No such file or directory.....
.
.when type"which mpirun", message is "/usr/bin/mpirun"

And I can not find the ./lmp_fedora

So what can I do to install successfully?please help me

cheers

cheng

Hi,
I want to visualize force network in grains by paraview. How can I dump force so that paraview can show force chain network?
Thanks for help in advance...
A

hello everyone,
we know that the liggghts has the function in calculating conductive heat transfer between colliding particles.
does liggghts have the avaiable function used to calculate conductive heat transfer between particle and wall when they collide?
thx.
S.L

Hi all

I wish to use an other material for the walls then for the particles, e.g. particles > glass, walls > Al. Under the fix mesh/gran I can specify the walltype by setting the number (ID) of the atom type. I did the following steps trying to use a different wall material:
1) read data file: 3 atom types
2) read data file: define the coordinates and properties for the 2 existing atom types
3) for fix property/global I spedified 3 youngsModulus, 3 poissonsRatios, 9 coefficientRestitution, 9 coefficientFriction and 1 characteristicVelocity