LIGGGHTS® - User Forum

i am trying to compile Liggghts-public without mpi to define correctly the Makefile.user steps by steps, so I have launch "make auto -e USE_MPI=off -e DEBUG_INFO=yes"
and I got an error where vtkParallelMPI appears! see :

Hi!

Im having trouble with read_data for a model with bonded particles (Schramm/Richti83) using adhesive particles (washino/capillary/viscous).

I cant seem to get the format right in the data-file. Is there a way to check what format my particles have (e.g. ID x y z ...) When I use write_data to create a file I get the following format:

Atoms

1 1 9.0780778811098348e-03 8.4565641784780238e-03 1.9864876941739838e-03 1.8000000000000000e-05 1.0000000000008616e+03 0 0 0

Hello all,

I am using LIGGGHTS version 3.6.0 and CGS units. I am getting this error:
ERROR: youngsModulus <= 1e8 required for CGS units

So I think the unit here is dyn.cm−2 (=0.1 Pa), which means the limitation here is 1e7Pa. Am I understanding it correctly?
If it is yes, then it is not consistent with the youngsModulus limitation in SI units (1e9Pa). So I am wondering why?

Thanks!

Hello, I'm really new to using LIGGGHTS. I find it really hard just to install it as I'm not familiar with the codes given on the installation tutorial. Is there any alternatives on how I can install LIGGGHTS? Thank you very much

Hi everybody,

I am showing the force chains of a granular assembly obtained from LIGGGHTS using Paraview.
Problem1: Scaling is occurring in the reverse order, i.e. the weaker force chains are thicker and the strong force chains are thinner.
Problem2: Horizontal lines can be seen joining the lateral boundaries.

PS: I am using periodic boundaries at the lateral boundaries

Any suggestions will be very helpful.

Thanks,
Sounik

Hello,
I need to compute some parameter that relates the forces on particles to the force on contacts. I assumed that if particle i have n contacts, by adding up the forces at each contact I will recover the total force on the particle (without external forces). Unfortunately, that does not seem to be the case.

Hello!

Hi,

I would like to know if it is possible to define the initial position of a multisphere in LIGGGHTS (eg. placing a cube in the bottom of a tank) instead of inserting it at random places in a domain?
Also, in the "multisphere_stone_restitution" example, I did not understand how the atoms' positions were defined: in the "stone1.multisphere" file, the x, y, z coordinates are all positives, but when I output the results in Paraview, the x and y coordinates are negative. How are the atoms' positions actually defined?

Thank you for your time,
Andrea M.

Hello!

I am a new user to LIGGGHTS and I have been doing a research related to the centrifugal compaction of metal powder particles. I have set a simulation which is taking quite a long time on my laptop.
I have set the thermo command to show the status each 10000 steps (there are 8E7 steps in total). I have noticed that while in the beginning after 1 hour 1 million steps have been completed now the simulation is much slower and now in 1 hour there are about 300 000 steps completed.

How can I rotate a region I created by intersecting other regions? I know this can't be done directly , is there a way around it?

Many thanks