LIGGGHTS® - User Forum

I am new user of LIGGGHTS and I have to study the granular flow on inclined plane with walls .

1. For that should i design the mesh which is already at desired angel or it can be simple plane with walls and gravity with component in x y and z direction.
2. How to design the inclined plane and and used mesh/gran command
3. how to see the simulation animation with LIGGGHTS.

Please any one clarify my doubts.

Regards
pnkumar

Hi All,

In some book and articles it's mentioned that coefficient of restitution isn't a constant parameter and it depends on impact velocity. I think it isn't implemented in liggghts and it may affect simulation results, so how we should consider this problem?

Thanks in Advance,
Reza

I find that the compute property/atom command dose not work with multisphere, it cant give the force on each atom(fx fy fz). It always be 0 0 0. I guess there should be a restriction along with the compute property/atom command. And I wonder how to get the resultant force on each multisphere body on each time-step.

Hi all.

I've downloaded the Voro++ package and installed it, but I still get the following error while using compute voronoi/atom:

ERROR: Invalid compute style (../modify.cpp:982)

I've followed the steps mentioned in the documentation while installing it, but I'm not sure what the following steps mean:

Hi all,

I'm trying to use langevin thermostat which is described in below link of liggghts:
http://www.cfdem.com/media/DEM/docu/fix_langevin.html

I use LIGGGHTS (Version LIGGGHTS-PUBLIC 3.3.0, compiled 2015-12-14-18:26:11) version of liggghts, but i got this error:
ERROR: Invalid fix style: "langevin" (../modify.cpp:820)

is this command supported by mentioned version of liggghts !??

Thanks in Advance,

Reza

Hi,

Recently, we were able to work in a cluster. Specifically it's a Stack IQ cluster, and we have some troubles with the mpirun command in order to use all the processors. My doubt is how is it work LIGGGHTS with a STACK IQ cluster?,is there a problem with his architecture?

Thanks and cheers

Nicolas.

I want to rotate a cylinder on its own axis at 3000 rpm as well as the origin (0,0) at 200 rpm. I am using move/mesh for this purpose. I am only able to rotate either on the local origin or on (0,0). I am unable to specify two rotations at the same time. Please let me know how to do this as in the manual it says it is possible to specify two rotations on a mesh. I would grately appreciate any help.

The code I am using is:
fix movecad all move/mesh/gran rotate 0.0 0.0 0.0 0.0 0.0 1.0 0.03 cad1

Hi all,

In the following paper:
Surface Energy and the Contact of Elastic Solids, Author(s): K. L. Johnson, K. Kendall and A. D. Roberts, Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 324, No. 1558 (Sep. 8, 1971), pp. 301-313

The cohesive energy density is mentioned in J/m2 but in LIGGGHTS we have to use the same in J/m3. So, can anyone elaborate the conversion method for cohesive energy density.

Thanks in advance.

Hello, everyone.
I'm a new user of LIGGGHTS and now I'm trying to run tutorial and examples.

All the examples work fine, except of contactModels/in.oldModels.
The error is: ERROR: Invalid pair style (../force.cpp:244)
The online tutorial examples also give me an error:
ERROR: Invalid fix style: "wall/gran/hertz/history" (../modify.cpp:820)

I guess it is because in both cases the

pair_style gran/hertz/history

is used. And my LIGGHTS cannot recognise it.

Hello,
I am receiving the following error when running the hopper drain example from the website.

mschramm@da200b-04 ~/Documents/liggghts/examples/LIGGGHTS/Tutorials_public/Bin_Sim
$ Liggghts<HopDrain_Bonds.txt
LIGGGHTS (Version LIGGGHTS-PUBLIC 3.3.0, compiled 2015-12-11-19:39:06 by mschramm, git commit 9b1fc57b77c483deaf2c0a6c69241c5d4f91e3c2 based on LAMMPS 23 Nov 2013)
ERROR: Invalid atom style (../atom.cpp:432)

I have been able to run the example using atom_style sphere but I now want to add a bond between two particles.