LIGGGHTS® - User Forum

Hi everyone,
I've been using and reading the heat/gran documentation and have a few comments...

1) In the writing (and I think an example case that comes with LIGGGHTS 2.x?) it says that the keyword is property/atom but then the example has :
set region srcreg property/peratom heatSource 0.5

I tried running this property/peratom and received errors. In some cases I do believe the property/atom did work. I just want to point out that I think there's a mismatch between the code and the documentation.

but

I'm trying to run a simulation using fix insert/rate/region to generate a settled bed of >1 million particles. The inserted particles should be distributed evenly across all processors. When I tried to run with 128 processors on an HPC system, I got this error:
ERROR on proc 31: Failed to allocate -68719476576 bytes for array FixInsert::xnear (memory.cpp:45)

Hallo,

I got a problem when inserting different sized particles. After the process of settling, I expect a somewhat plane bed of particles (which is what I get when i use monosized particles). I attach a picture of the problem to clarify the problem.

As you can see, the particles on the right side are on a higher level then the ones at the left side, which is kind of strange.

Particles are inserted via

Dear LIGGGHTS users,

I have a problem. Would you mind helping me?
I upgraded my version to 2.3. When I type liggghts < in.conveyor for example I recieved this message:

"The program 'liggghts' is currently not installed. You can install it by typing:
sudo apt-get install liggghts"

But when I type "sudo apt-get install liggghts" I recieved this error:

"E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?"

Which compute styles, fix styles, and pair_styles are necessary or useful to simulate rotating geometries like Ball mills? I want to simulate a Ball mill with 2, 4, 6, and 8 lifter as well as with different radii (Attached Fig.). Any suggestion would be appreciated.

Hello all,
Thanks in advance. I have been using LIGGGHTS for quite long now but after i create my restart file with LIGGGHTS 2.3 and when i restart my simulation with it fix ave/time does not work it stops without any error messages. further information about restart are, pls take a look into my code,
number of atoms - 322511,
restart code is,
#---------------------------------------------------------
log restlog.txt
variable r0 equal 0.06
variable re equal 0.075
variable rs equal 0.001
variable ht equal 0.30

Hi all,
I am currently doing a survey of contact laws implementation for granular materials. I have been reading LIGGGHTS manual and some workshop material available online, but for the moment I fail to find the equation of the "tangential component of velocity" at contacts.
It may sound a dumb question, but there are actually many possible definitions of this velocity. Any pointer to this equation in LIGGGHTS would be welcome. Thanks!

Hi All,

I have a few lines of codes which I designed to count the particle numbers in the region mid_reg. I used if & then sentences, however, I found the if-then codes only worked on run 1, not constantly updating.

Has anyone got any ideas.

Cheers,

I would like to set any small numbers (e.g., below 1e-15) to zero in my dump file. If I do not do this, paraview does not like my vtk files - I get the error: "Error reading ascii data. Possible mismatch of datasize with declaration."

Does anybody know of a simple way to do this using dump_modify or a similar command in the input script?

Hi,
I am trying to dump the contact force to vtk file in order to see the force chain by Paraview. However, it shows no snapshot. I saw that Mark Bentley had coded it. But when I install the EVTK by "python setup.py install", it shows an error as "gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/lib/pymodules/python2.7/numpy/core/include -I/usr/include/python2.7 -c src/cevtk.c -o build/temp.linux-i686-2.7/src/cevtk.o
src/cevtk.c:4:20: fatal error: Python.h: No such file or directory
compilation terminated.