LIGGGHTS® - User Forum

Hey guys,

Hello again,
I'm working with a program, based on the tutorial Continuous Blending Mixer.
My Problem is, that at the insertion area, the particle start to "explode" at a certain time.
That means, some of the particles are going through the wall of the .stl-file.
The starting velocity of the particles is high enough to avoid, that some of the old ones are still in the area, when the new ones are created.
I'm shure, that the area they are created is not too small and there is plenty of space between the the area they are created and the wall.

Hi all,

In the doc of DEM simulation, the effective shear modulus is:
1 2(2+v1)(1-v1) 2(2+v2)(1-v2)
-- = ------------------ + -------------------
G Y1 Y2

but, the in the global_properties.cpp, line 217:
matrix->data[i][j] = 1./(2.*(2.-vi)*(1.+vi)/Yi+2.*(2.-vj)*(1.+vj)/Yj);

The above two don't match, which one is wrong?

Appreciate any help in advance!

Hi guys,
What happened wrong when there is a erro message like Internal error (tri_mesh_I.h:90)? Thank you in advance for your answers
Cheers,
Zyan

I am using a cylinder region to add external force in a domain. The script for the domain is a s follows

region a cylinder z -0.343 -0.004 0.6 -0.4025 -0.2375 units box
fix push all addforce 0.0 0.0 -0.1 region a

Is there any error in the script. Please help me out.

Thanks in advance.

Hi all,
this might be an easy one for some of you, but I can't figure it out.
Basically I want that all particles are fixed/stationary throughout the entire simulation.
Thank you soo much

I am trying to incorporate two separate force fields for two separate block regions in a single input script as I need to giving force in two separate regions

I am using the following script for one block

#zone 1
region spray block -0.0295 0.0555 0.2 0.24 -0.016 0.014 units box
fix push all addforce 0.0 0.1 0.0 region spray

I tried to add the same set of commands for the other for the other zone but its giving error

#zone 2
region spray block -0.01 0.05 0.3 0.4 -0.06 0.01 units box
fix push all addforce 0.0 0.1 0.0 region spray

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) ?