LIGGGHTS® - User Forum

Hi,
How can I define material properties of 3 types of particles? As, I want to use different friction between particle-particle(0.1), particle-bottom wall(0.0) and particle-side walls(0.7). Is this correct way of defining:

fix id all property/global coefficientFriction peratomtypepair 3 0.1 0.0 0.7 0.7 0.7 0.0 0.0 0.7

thanks,
Ram

Hi,

I'm a new comer to use LIGGGHTS. I can see that the characteristic velocity is a parameter used in the contact model of LIGGGHTS. What's its physical meaning and how to set it?

Thanks!

Jerry

Hi, Christoph, i simulated a compression test, but i found the particles crossed the top wall after compression. Hete is the simulation procedure. First particles are poured into a 0.5 m high cylinder without topwall, result is saved for restart; then in the restart file, the topwall is imported and moved to compress the particles. I couldn't find the reason for particle crossing wall. Can you help me? by the way the version i used is 1.2.6 beta.
Thanks,
Ada

Hello everybody,
I am having troubles with compiling the LIGGGHTS project. Everytime I call make makelist I receive the error "grep: cfd_regionmodel_*.h: No such file or directory". I am able to compile the project with g++ from terminal, but I need to fix this error because I want to compile the project with Codeblocks so I can debug it. I had the similar error with the atom_*.h and dihedral_*.h but I fixed it by installing the package CLASS2. I am using the serial_debug makefile.
I would greatly appreciate any help.
Thanks Tomas

Hi LIGGGHTS Users!

I have run into this problem where LIGGGHTS fails to restart in some cases (I guess when the particle-tri contacts are high) and exits with the following error:


Reading restart file ...
orthogonal box = (-0.00065 -0.00072 0) to (0.00065 0.00072 0.002)
1 by 1 by 1 processor grid
2198 atoms
Resetting global state of Fix zwallbottom Style wall/gran/hertz/history from restart file info
Resetting per-atom state of Fix zwallbottom Style wall/gran/hertz/history from restart file info

Importing STL file 'WireAssembly.stl'

Hi all,

I use the version 1.2.5 and I have this warning when spheres are in contact with triangular facets:

WARNING: Dangerous build in triangle neighbor list.

Please, can you give more information about this error message ?

Moreover, please can you indicate me the function where the neighbor list between spheres and facets is built. I use the function fix_wall_gran_hertz_history

Regards
JF

Hi!

I would like to know, if "Liggghts" works on the Linux version "Open Suse"? Or does it only run on "ubunto" and "fedora"?

Christian

Hi All

Hi!

I was wondering if there is a way to create composite objects in LIGGGHTS made out of other objects. For example, building a tetrahedron out of 4 spherical atoms.

If this is not possible, are there other ways to create objects with more complex geometry that can move and interact like atoms? I would like to create these objects but still have the "smoothed" spring-like model for interaction between each other.

Stefan

Hi All

I am trying to run the LIGGGHTS granular pair style with an "old" LAMMPS pair style. To do this I am using the "hybrid/overlay" command to include the effects of both pair styles. My input script runs fine with the plain granular system, but as soon as I use the hybrid/overlay command I get a segmentation error as given below (the first line shows the last line that was reached in my input script):

fix wall all wall/gran/hertz/history 1 0 mesh/gran 4 bottom top inner outer
[dwain-dunn:03288] *** Process received signal ***
[dwain-dunn:03288] Signal: Segmentation fault (11)