LIGGGHTS® - User Forum

Hi,
I have a problem with memory. My memory is about 16 GB but not enough for my simulation. It can not finish because It stuck an error seems like memory is full. How to figure out this problem?
P.S. When i implement code with cohesion it will use so much memory. If don't use cohesion it quite OK can run till finished

##Technical Info:##
error messages:

ERROR on proc 0: Failed to allocate 783451440 bytes for array neigh:binhead (memory.cpp:45)
--------------------------------------------------------------------------

2 questions:

1. Is there any way to change the moment of inertia for particles separate from changing the mass? I'd like to run granular simulations where the particles can't rotate as easily, but I don't want to give them an arbitrarily high mass (density). Does LIGGGHTS support this?

Dear all:

I use 'fix roch all move/mesh mesh ch rotate/variable origin 0 0 0.6 axis 0 0 1 period 6.28' in in.simulation file in order to rotate 'ch' around the z axis under certain angular velocity.

But I get a error

ERROR: Variable name 1 for fix move/mesh rotate dynamic does not exist (mesh_mover.cpp:328)

How to solve the problem?

My LIGGGHTS is 2.1.X.

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.