LIGGGHTS® - User Forum

Im working for the simulation of metal hydride particles in a container. The particle size is of the order 100 micron and the cylindrical container has a radius of 12mm and 20mm height. Can u suggest a proper insert/rate/region command, velocity etc.. for this particular situation. I need to find the container wall stresses. Please help me to prepare the syntax. Im a beginner in liggghts.

Hi,

I am using glued-spheres particles to do my simulations and I want to calculate the contact forces between these glued-sphere particles.

I know I can get the contact forces between individual spheres using 'compute 1 all pair/gran/local' command but I want to treat one glued-sphere particle as a single entity and when two glued-spheres will be in contact there will be multiple spheres from both the glued-spheres in contact. I want the summation all the forces acting on the individual spheres for that contact pair.

Hi all,

Dear all,

I am using the servo wall model in version 3.3.

I have a bottom wall and a top wall, the particles are between them.

As the first test, I let the bottom wall far away from the particles, and the condition of it is:

mesh/surface/stress/servo meshes/bottom.stl type 1 stress on com 0 0 0 ctrlPV force axis 0 0 1 target_val 10 vel_max 0.01

because there is no contact between the particles and the bottom_wall, I assume the movement of the bottom wall should be:

Hello all,

I am using compute_stress/atom ke pair. And in Documentation it is mentioned that it doesn't include the contribution of average velocity in kinetic energy contribution. Is there a simple method to include that as well in stress calculation? So right values of stress which will be dumped.

Thanks in advance.

pnkumar

I am learning to use liggghts with tutorial examples.
The example of continuous blending mixer does not go through compiling and always gives an error of:

I am learning to use liggghts with tutorial examples.
The example of continuous blending mixer does not go through compiling and always gives an error of:

I'm a new user and I'm still learning the most helpful commands to run my simulation. In my script I use the ''hertz tangential history rolling_friction cdt'' model. I would like export:
- the collision time
-number of collision
-normal and tangential forces
-energy dissipated

do you know which commands allow me to export these quantities?

kind regards
I hope someone can help me.

Hi All,

Attached are STLs and input script (remove the .txt). I want to know how to run this script so that ins1 runs 20000 time steps then ins2 gets in and runs for 30000 time steps. In short, ins1 will run 50000 time steps and ins2 runs for only the last 30000 time steps.

Thank you for your help.

Hello. I need someone to help me.

I installed and compiled Liggght version 3.3.1 and I have done checking at SRC / version liggghts.h for double check the version.
Then, I have tried many times to run the example. Unfortunately , still it does not work. This is due to my current liggght version is 2.3
8 as stated in terminal.

ERROR :Invalid pair style (/build/buildd/liggghts - 2.3.8/src/force.cpp:181)

What could I do to fix this problem.. Anyone could help me pleased.

Thank You.