LIGGGHTS® - User Forum

Hello
I am using LIGGGHTS-flexible fiber version. I have a minor question regarding "bond/create/gran" to create granular bonds.
In one of the tutorial the syntax of the above command is as follows:
fix bondcr web bond/create/gran 1 1 1 ${bond_skin_web} 1 6 #every itype jtype cutoff btype newperts

I just wanted to understand the meaning of the last entry (newperts=6)

Thanks

Hi Everyone,

Is it possible to read a specific column of data from a text file?. This file is produced from the fix print, to be used in the next simulation steps.

Thanks

Hi
I am currently using liggghts-flexible fiber version. My question is related to the shear_box tutorial for the same.
Similar to the above tutorial, I first deposit fibers in a confined volume, then compress the fibers from above. For the wall geometry, I am using the .stl files. Once the assembly is fully compressed, I create bonds between the fibers. So, we now have a cross-linked fiber network.

liggghts tutorial "heatTransfer_1" set the temperature using the following codes defined to assign 800 degree to the particles at the right half packing.
see the official web: https://www.cfdem.com/heat-transfer

#set particle temperature for half the bed
region halfbed block 0 INF INF INF INF INF units box
set region halfbed property/atom Temp 800.

Dear LIGGGHTS users,

I tried to insert particles into a cubic simulation box with periodic boundary conditions. The particle sizes vary considerably (Dmax/Dmin=80, D: particle diameter). It is OK to construct the initial packing structure with a core, but when the number of particles become very large and need to use multiple cores, some domains are only filled with large particle with no small particles. I have used "communicate multi" and "neighbor multi" command.

Could you please tell me how to solve this problem?
Any help will really be appreciated.

Hello,
(Edit : Moved to liggghts users forum)
My simulations have been hanging when running them on several nodes. They work fine in a single node with several cpus. I was able to get a Minimal Working Example based on the packing example. Just by adding a single line
write_dump all custom out/dump_initial.gz id

Dear LIGGGHTS users,

I want to apply a constant pressure on the top wall and let the bottom wall being frozen.
Could you please tell me the appropriate command to achieve this?

Thank you in advance.

Best wishes,
June

Dear LIGGGHTS uses,

I am now simulating a system with millions of particles . Can GPU acceleration be used for LIGGGHTS?

Thank you very much.

Best wishes,
June

Dear LIGGGHTS users and developers,

I am trying to create an intial packing strucutre of three different size particles: 1, 10, 50. The numbers of particles are 100 (D=1), 10 (D=10), 3(D=50) and the initial volume fraction is 0.15. I have tried two insert command:

1. fix ins all insert/pack seed 32452867 distributiontemplate pdd1 vel contant 0.0 0.0 0.0 insert_every once overlapcheck yes all_in yes
particles_in_region 113 region bc

Hi
I am currently using LIGGGHTS-flexible fiber version.
My problem is somewhat similar to the shear box tutorial. I first create fiber templete by bonding the spheres; bonds and atoms are of type 1.
After fiber -fill in a space and depositing them onto a plate, I want to bond those fibers whose separation is less than a critical value. I want to create a bond of type 2 for inter-fiber bonds.
Since I have atoms of type 1 through out, how should I ensure that atoms are bonded with bond-1 within a fiber, however, with bond-2 inter-fibers (cross-link).