LIGGGHTS® - User Forum

Hello everyone.

I've been working on a pebble bed for which I'm trying to do some numeric experiments with stiff, brittle, ceramic pebbles. As a first-order test of the bed, I'm using the fix/evaporate command to remove pebbles from the bed and watch how the new ensemble evolves under load. I'm also monitoring pebble contact forces with the compute of pair/gran/local. I've run into a bit of a snag.

Hi Guys!

I´m trying to configure a simple test case. I took movingMeshGran as a start point for my angle of repose test, but I find that the inserted particles pass through the solid "bucket.stl". Post-proccesing the result I find that the bucket "became" a solid at 150 paraview timestep.

http://imageshack.us/a/img10/5841/screenshot3zl.png

Hello,
I had installed liggghtsdev 2.0.5 version which was updated automatically to the new 2.2. version. Opening the manual(http) from the doc folder I encounter the problem that the liggghts commands resemble the 1.5.3 commands. E.g., the new arguments of the mesh/gran/stressanalysis I saw for 2.0.5 before, are replaced by the arguments as for the 1.5.3 version (the same for pair_style gran/hertz/history). Is there any other possibility to access the manual or commands?
Thanks!

Hi guys,

I am setting up a test case with a sand particle colliding into a sand bed. When I do small particles, I got the error saying that volume expectancy was too small. I want to have a mix of 100 micrometer and 10 micrometer particles. It seems there is a limit set in the particle template code.
What is the minimum diameter for particles that LIGGGHTS can handle? If I want to do smaller particles, can I scale gravity and other coefficients to overcome the limit?
There was a similar topic before:

node/493

Does anyone know what this error means?

"ERROR: Domain too large for neighbor bins"

If I have a mesh indenter, and want to visualise which particles it has contacted, is there an easy flag that can be set in the input file?

I'm assuming that I haven't seen one in the documentation because it isn't that simple (rather than having just missed it!). If so, anyone have any ideas for implementing this?

This is basically a continuation of my last thread with this title. I updated to v 2.2 and my simulation no longer freezes. However, my simulation now runs as if my granwalls aren't there. My .stl dumps look correct, but looking at .jpg dumps (and even just the number of particles in the simulation region), you can see that the particles just fall straight down and out of the region, without interacting in any way.

warning messages:


Setting up run ...
175 mesh elements have high aspect ratio (angle < 0.500000 °)
WARNING: Mesh contains highly skewed element (multi_node_mesh_parallel_I.h:513)
Import and parallelization of mesh cad containing 1448 triangle(s) successful
149 mesh elements have high aspect ratio (angle < 0.500000 °)
WARNING: Mesh contains highly skewed element (multi_node_mesh_parallel_I.h:513)
Import and parallelization of mesh cad2 containing 10288 triangle(s) successful
INFO: Resetting random generator for region bc
Memory usage per processor = 11.1755 Mbytes


Hi, all.
I'm new to LIGGGHTS and Linux, and I'm quite interested in DEM simulation, so I begin my study on LIGGGHTS.
During the past few days, I ran into lots of problems during the installation of LIGGGHTS and its post-processing tool (lpp improved based on pizza.py), thanks for helps from the forums.

Now I'd like to share my experience of installation, which is not shown in Installation Tutorial. My OS is Ubuntu 12.04, initially I use Fedora 16, but my friend suggests Ubuntu is suitable for newbie :)

Hi all
I have installed LIGGGHTS and it works well with its examples. But when I want to run lammps examples it does not work for some of them. I ran the lampps examples in the same way as liggghts examples and it works for some examples such as "intend" and "rigid". But it does not work for "dipole" and "eim" examples. there is the error massage for these examples in the following:

liggghts