LIGGGHTS® - User Forum

I've been trying to debug some nuclear heating and thermal expansion adaptions that I've been having with my input script. To help with the debugging I just took the input script from heatTransfer_1 example and added a few lines of code. When I run this on my laptop (LIGGGHTS 2.3 on a Mac) there's no problem.

If I take this exact same code and run it on my lab's server computer (LIGGGHTS 2.3 on Ubuntu) it goes all wonky. The pebbles act as if there are no walls, and the particles just fly out of the system. I narrowed it down to a single line of code. The suspect line is:

For LIGGGHTS, I just noticed the periodic boundary condition is enforced during the post-processing by lpp. Is there a way to do it in liggghts so the particles exiting the region will come back through the boundary in the other end? Really appreciate!

Hi Christoph,

Thank you very much for your reply, Sir i found that once i generate restart file for my cylindrical couette flow simulation after 10000000 timesteps ,

i ran this restart code ,

#------------------------------------------------------------

atom_style sphere
newton off
communicate single vel yes
atom_modify map array

#-------------------------------------------------------------

timestep 0.0000002
read_restart data.10000000

#-------------------------------------------------------------

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!