LIGGGHTS® - User Forum

Hi everyone,

Greetings! I'm a student and a new user to Liggghts. My current work is to build a model which is a plate moving horizontally in a pool full of granular particles. Now my plate can move very well, but I don't know how to extract the total reaction force on the plate, can anyone give me a hint please?
Any help is very much appreciated!

Warm regards,
Carol

Hallo,

I have created one layer of particle by using the following statements:

Hi everyone,

I am using compute pressure command to extract the normal pressure on x,y,z directions. I managed to use this command by using compute all temp, but the temp result obtained by this command looks like the molecular temperature. finally, the compute pressure command gave a 6 elements vector rather than an array of one scalar and on vector documented on the websites.

does the 6 elements vector I got have the definition on those website of compute pressure?

Thanks
Weijing

Hello everyone,
I have a problem, which I could not solve on my own.
I have a complex rotating .stl-geometry.

When I'm doing a restart of my program, the geometry is lost (so I think).
Therefore, I initialize it newly but the former position of the geometry is lost.

i m working on simulation of poly disperse flow of granular material . when i try to run script file in terminal it gives following error . can any body tell me whats the reason of this error

Hello,

Is there any way to dump the multispheres properties so that I can visualise them correctly in Paraview, for their actual mass, volume or spherical equivalent radii?

Thanks

Best regards
Matteo

Hi All,

I meant to ask if it is possible to include a command in the job input script to perform post-processing.

For instance, I have included in my script;

variable a universe 1 2 3 4 5 6 7 8 9

and defined results post directories as;

post_0.$a

My dump files have the format dump*.data so;

shell cd post_0.$a (I am sure gets me into the directories) and now I want to execute;

lpp dump*.data (Which I normally execute from the terminal - How do I include this in my job input script).

Thank you.

Hello all,

I am new in LIGGGHTS so would need some help:

As part of my degree final project (related to modeling of electro-filters) I am trying to simulate the interaction between charged particles with/without an external electric field.
I have been researching the manuals, the forum, etc, but I could not find a solution to my problem:

I do not know how to add coulomb interaction between particles. I found on this forum that -in previous versions- this could work:

Hi All,

Is there a way of conducting parametric study with one input script and saving dump files in different post directories. I mean say vary coefficient of rolling friction such as 0.1, 0.2,...,0.8, 0.9 and save the dump files in different folders say post_0.1, post_0.2,...,post_0.8, post_0.9.

Thank you.

Hi

I am trying a mulisphere break case.

In the LIGGGHTS Tutorials-public "multisphere_stone_restitution" example in.multisphere file, I add

"fix m6 all property/atom fz scalar yes no no 0.02"
before integrator, and change integrator to be

"fix integr all multisphere/break trigger_threshold 0.1 trigger_timeStep 0 trigger_fixName m6"

After type ./lmp_fedora -echo both < in.multisphere2, I get the ERROR of