LIGGGHTS® - User Forum

In the simulation I need particle A to remain in the main simulation box A while particle B will travel through the wall of simulation box A into box B at a random location based on the packing depth of particle A.

Hi colleagues,

I want to ask is there any method to delete particles with a certain diameter. In my simulation, I have the particles with diameter ranging from 1 mm to 10 mm, now I want to delete the smallest particles with d=1mm. I have sought the command "delete_atoms group" while found I con not define a group with a certain diameter. How could I delete the smallest particles? Could anyone give me any clues? Thanks.

With regards,
Zheng

Hi all,

Dear all,
How do I install LIGGGHTS version 3.1.0? I need to use the SEAICE user package which was written for LIGGGHTS 3.1.0. I want to simulate wind blowing the sand away from a sand dune.. causing avalanche etc.

Hi,
I'm interested in using the Thornton Ning contact model that was implemented in release 3.8.0 in LIGGGHTS. I also read in the release post that "currently there is no doc yet, this will hopefully be in the next release.". Is there anywhere I can read about the implementation of the contact model?

I am trying to use LIGGGHTS to model bricks in a masonry structure. I am using the superquadric particle template with blockiness parameters of 4.0 and axes lengths of half length, height, and width. This works fine for regular walls where bricks have a parallel arrangement.

However, I would like to be able to model arches and other curved structures, as well. In these cases, the super quadric needs to be inserted at an angle. I do not see a way to do this in the documentation (linked below). Does LIGGGHTS support this functionality?

Hello,

I'm trying to build a pipe shaped volume for my LIGGGHTS-simulation using the following commands

region cout cylinder z 0. 0. 0.04 0. 0.3 units box
region cin cylinder z 0. 0. 0.003 0. 0.3 units box
region cd intersect 2 cout cin

When I run the calculation I get the error message 'unable to calculate region volume'.
So how is the right syntax to create a pipe volume?
Thanks for help

Florian

Hey everyone,

is it possible to suppress/stop the terminal output? For example this output:
Total # of neighbors = 5195
Ave neighs/atom = 1.9678
...
...
...
Loop time of 0.0997219

I want to speed up my overall simulation time and I hope this will do it at least a bit.
I haven't found any existing post, so I'm really grateful for any input.

Greetings,
Schuette

Hi!
I'm a new user to LIGGGHTS and have a question about the units for cases. How does it work with units in LIGGGHTS; is the code always solving in the unit specified for solving equations or are there cases where it will automatically change to SI units instead?
Is it specified the dimensions of model parameters for example that youngsModulus should be in Force/L^2 i.e. pressure? How can i check what dimensions the model parameters should have?

Hi all,

I want to analyze the average force per contact by diameter.

Using the command "compute pair/gran/local force id pos", I can obtain the id of the two contacted particles. Then using the command "compute property/atom diameter", I can obtain the diameter of each id. Based on some coding in Matlab, I can obtain the average force per contact by diameter. This procedure may not be that direct and I want to know is there any better method to output what I need?