LIGGGHTS® - User Forum

Hello, everyone,

I have been working on a simulation that involves the random compaction through uniaxial pressing of particles with varying size distributions, using two different material types to create a composite. Up to this point, the process and simulations have been straightforward, and LIGGGHTS has been an invaluable tool.

Hello,

I am currently facing challenges in resuming a simulation that involves superquadric particles formed by gravitational settling.

1. My initial approach was to utilize the "read_restart" command in a subsequent script file. Unfortunately, this method does not allow for resizing the simulation box with the "change_box" command.

2. My second attempt involved the "write_data" and "read_data" commands. However, I discovered that these commands do not support superquadric particles.

Hi everyone,

I'm very new to LIGGGHTS, and I'm having troubles to create a simple simulation.

As a starter, I want to create a simulation where a single particle (metal particle) is settling in air and another simulation where a single particle is settling in viscous medium (like a resin).
When a particle falls in air, I just want to have force of gravity acting downwards on a particle.
When a particle falls in a viscous medium, I want to have drag force acting upwards on a particle, while force of gravity acting downwards on a particle.

Hi Everyone,

I am analyzing a sieve geometry for particle transfer. The CAD model of sieve plate is complicate with around 1 Mio. of tessellated faces. Hence, reading and "import and parallelization" of this taking huge amount of time. Is there any alternate way to speed up this time? I can't use the recently introduced model "massflow/mesh/sieve" fix command because most of modelling data require here is unknown.
I also tried converting the STL file to VTK using Paraview tool but it also did not work.
Any suggestion that I can try?

Regards

Hi everyone,

I am trying to simulate a rock under point load, similar to what is described in the LIGGGHTS-WITH-BONDS documentation in.bond. My model consists of different clusters, and I intend to start with two types of atoms (type 1 and type 2) that are randomly distributed within the model. Additionally, I want to define three types of bonds: bond1 between atom type 1 and atom type 1, bond2 between atom type 2 and atom type 2, and bond3 between atom type 1 and atom type 2. I have a couple of questions:

Hi everyone,

I am somehow a beginner in using LIGGGHTS, and I want to make a model consisting of different clusters using LIGGGHTS-WITH-BONDS. I aim to create a model with two different types of bond properties (stiffness and normal and shear bonds), and I want to assign atom bond type 1 to some atoms and atom bond type 2 to others. Is it possible with LIGGGHTS-WITH-BONDS? And is there any example that can help me?

Thank you Tannaz

Hello!

I am using LIGGGHTS FLEXIBLE FIBERS. I made flexible fiber from 50 atoms bonded togeather. I am cutting this fiber by blade and determing loads on blade. I want to make a fiber, which would better describe shape of real fiber so I let atoms overlap, which means I had to turn off pairwise forces. I did that by command neigh modify exclude (with this command I turn off creating list of neigh atoms). But when I use this command forces which were applied by command bond style also disapear.

I am inserting a plate (STL mesh file) into a LIGGGHTS simulation and moving it up and down in a bed of grains. I am trying to output data about the electrostatic forces on the plate but all I seem to be able to dump from LIGGGHTS is the position of the plate. Does anyone know if there is a way to output state data from STL files used in LIGGGHTS simulations?

how to make data file from the VTK file for LIGGGTS?
Explanation-I want to read particle's coordinates and velocities from the VTK file and I want to start new simulation from that VTK file. How to do it?

On a RHEL 9 cluster with VTK installed, why would this seg fault? I just used 'make auto' and OpenMPI 5.0.2.

mpirun -np 4 lmp_auto< in.chute_wear
LIGGGHTS (Version LIGGGHTS-PUBLIC 3.8.0, compiled 2024-02-20-15:56:33 by me, git commit bbd23c8521fe0a4f3f5bfd0d3dc9a7dddd68d90b)
Created orthogonal box = (-0.5 -0.2 -0.4) to (0.1 0.2 0.15)
2 by 1 by 2 MPI processor grid

Reading STL file 'meshes/simple_chute.stl' (mesh processing step 1/3)