LIGGGHTS® - User Forum

Dear all,

I would like to count the overall number of collisions between different types of particles.
For example, I have particles type 1 and particle type 2, I want to know how many times
during my simulation a 1 particle collides with a 2 particle. Is there a way to do this?

Thank you,
Charlie

hallo all,

is there a way to use cad-files (e.g. stl-files) for the command: fix wall/region command ? Or do I have to define the regions by hand?
region cuboid block 0 0.5e3 0 0.5e3 0 0.5e3 side out

Any comments are appreciated, thanks

Joh

Hello,

I am simulating a shear cell using a servo wall as the top surface and a moving mesh as the bottom surface. The rotation period I set is some seconds.

Hello all,

Heat transfer between two particles is calculated by fix heat/gran with the equation given on

http://www.cfdem.com/media/DEM/docu/fix_heat_gran_conduction.html

Hi All,

I am simulating granular flow on a conveyor belt. Is there a way of tracking individual particle position, forces, velocities per time step or through out the simulation run.

Theo_Score

Hi!
I'm manteining the LIGGGHTS PKGBUILD in AUR. Any doubt, compilation error or suggestion you can make it right here.

You must to install liggghts and liggghts-lpp (Pizza.py) from AUR.

it's you use yaourt, it's enough with:

yaourt -S liggghts-lpp

And you will get the liggghts, pizza and lpp command in /usr/bin

Hello everyone,

I am trying to extract particle velocity and position only one time for each collision, by reading the output only in the first timestep the contact takes place and ignore the output for the rest of contact duration. I want to use these properties by variable command and fix adapt to update particle diameter.

I tried to use "pair/gran/local command", but this command gives me the output every timestep the two particles are in contact and that's not what I needed. I want only one particle property reading for the whole duration of each contact.

Hello,

I'd like to know if in the latest release of LIGGGHTS is implemented the possibility to move a mesh through a periodic boundary condition.
It is mentioned a "very special context". Can you tell me more?

Thanks a lot and have a nice day,
rob1

A part of my syntax is given above.

#parameters for gradually growing particle diameter
variable alphastart equal 0.0001
variable alphatarget equal 0.000125
variable growts equal 50000
variable growevery equal 40
variable relaxts equal 20000

I want start particle insertion after a certain time. I assume this should work with the "start" keyword of insert/stream. However, even if I use the "start" keyword, paticle insertion starts from the beginning. My code looks the follwing:
fix ins nve_group insert/stream seed 5330 start 1e4 distributiontemplate pdd1 &
nparticles 10000 massrate 1e-1 overlapcheck yes all_in no vel constant 0.0 0.0 -1.0 &
insertion_face partIn extrude_length 1e-2
Can anybody give me a hint what's the reason why the "start" option does not work correct?