LIGGGHTS® - User Forum

Hi,

I am new to LIGGGHTS. I am looking into the example input script given in the LIGGGHTS documentation. I can see that the 'region' command was used twice in the input script. I do not understand why the 'region' command was used twice. What was the purpose of using the 'region' command twice? I am adding the example input script below. It will be a great help for me if you can explain the reason behind using the 'region' command twice in the input script.

Hi everyone!
I am working on a simulation that involves a rotating drum and I've been investigating between the different output I get when I set its rotation using the two commands I mentioned.
In particular, I am interested in the total force acting on the particles, therefore I used in both cases the mesh/surface/stress fix-style and I noticed that it leads to different results in both forces and trajectories of the particles.

Hello everyone
I am trying to conduct triaxial test using LIGGGHTS. My boundary is a cube made up of six STL files ,the size of one STL file is 0.2 meter. In the begining, they are crossed with each other, and particles are inserted in the center region, a cube with side length of 0.1 m.
I used servo command to accomplish isotropic consolidation.After that, I compute wall's position, unfix servo wall and fix new wall on the top and bottom.Using move/mesh command to move the top and bottom walls while lateral walls remain servo walls.

Hello,
I would like to have create a vector (myVec) and be able to call individual values in an input script

Something like the following.
variable myVec (I have No Idea) [1,6,2,8,4,7]

variable singleVec equal ${myVec[2]}

I see that we can input an environmental variable and use it in the liggghts script but I would like to keep it contained in an input script.

any idea?

Dear all

I am doing triaxial test simulation, but I am facing some problem.

1. First, I applied six servo controlled wall using command to execute a confining pressure on a cube soil specimen, with the following command.

cohesion model consist of cohesive energy density as one of the input parameter. Based on the number of particle how to change the cohesive energy density value. What is the basis for calcilation of cohesive energy density?

Hi,

I am new to LIGGGHTS. I am looking to the LIGGGHTS tutorials. Can someone please explain where do I mention the number of particles in the input script for LIGGGHTS?

Thank you.

I am attempting to use the multisphere break command to break apart the particles upon exceeding a vertical force. However, I receive an error stating that 'trigger_name' is an unknown command. Note I do not receive an error when the command is changed to 'trigger_fixName' and an appropriate fix is given. However, I intend to subject a multitude of multispheres to a compressive force, which continually increases. The code is shown below.

#Multisphere

atom_style sphere
atom_modify map array sort 0 0
boundary m m m
newton off

DEM simulation of granular material using original particle size of 1 mm run for a while and then terminate automatically, while the when particle size increased to 5x-10x then simulation run correctly. What could be the reason for this? how this issue can be solved.

Hi everyone,
I'm try to simulae a tumbling mill and I want to estract some data such as the impacts number and the impact energy of the particles;