LIGGGHTS® - User Forum

Hello,
I'm trying to model a mixer, which mixes two different particles. To improve the handling of the results, I'm trying to save the data of the particles/atoms in to different files.
Without any success ...

Here the basic situation:

Hi,

I have 6 particles rotating with the same angular velocity. The rotation is caused by a torque, set by fix addtorque.
The problem is that i cant get the rotational speed by compute property/atom and also in paraview it is shown that the aprticles have no angular velocity but I can see them spinning in paraview.

fix integr all nve/sphere

dear all
I want to simulate separation of heavy and light particles in Knelson concentrator using DEM by LIGGGHTS 3.0.1
this concentrator works with mixture of particles and water but here I ignore the water. heavy and light mineral particles are separated based on differences in gravity and centrifugal forces while the concentrator rotates very fast.
there are some problems I encounter during my simulations:
1) I can not insert particles with specific features like size, density, percent ... uniformly inside the concentrator (look at the input attached file) ?

I have recently started using lammps and am trying to simulate granular poiseuille flow using the LIGGGHTS. Now I want to use gran/hooke as pair_style but it showed me the following error on compilation "Illegal fix property/global command, not enough arguments (fix_property_global.cpp:50)", though I have used all the fixes for the gran/hooke pairt_style. including the coefficient of restitution, young's modulus, poisson's Ratio ,characteristic velocity and coefficient of friction.

Hi,

I'm going to simulate a cylinder with the bottom lid as a rotating disk. I do not need mesh. Is it possible to declare the region in this way or I have to import CAD ?

Thank you in advance for your assistance

Hello, Christophe, Hello all,
Is elasto-plastic pair style implemented in Liggghts? Thank you
Cheers,
Zyan

Hi Christoph, Hi LIGGGGHTSers,
Rencently, i am working on simulations of stirring a peller (steel) in a vassel with particles (radii =1 mm, glass beans ). The simulation behave strangely, withparticles flowing everywhere out of control (cf. attached figure: bad_normal_e). The properties are given at the bottom.

Hi.

I have a question

I want to calculate the collision energy between balls in a ball-mill.
So I'm trying get the value of the kinetic energy of balls when a ball contacts another ball.

The condition of atom type is granular,

I have used "compute pair/gran/local command ",

as describe below

compute pa all pair/gran/local id

and, I've gotten the IDs of balls(atoms) which contacts another balls with as c_pa[1], and c_pa[2].

I want to make group which have the atom IDs in c_pa[1], and c_pa[2] ,but i couldn't that.

Hi,

when I try to use addtorque on particles there occurs an error with 'too many neighborbins (neighbor.cpp:1747)'.
Without the addtorque its working. To use addtorque I went before in the src directory and did 'make yes-user'. Then make clean-all and make fedora. It is now running a few timesteps but then the error occurs. Is there maybe a better way then using addtorque?

thanks
Joshua

Hi everyone,

I noticed that a lot of papers suggested reducing Young's modulus (shown in Hertz contact model) by several orders in Engineering modeling. But I didn't find any guideline on how many orders are proper in doing this, especially for a binary system. Can anyone give me some reference? Thanks.