LIGGGHTS® - User Forum

Hi everyone,
I am doing triaxial test simulation. I want to compute the Unbalance force index (Formula is attached with this post), and change the strain rate accordingly within the script. I have tried to compute contact force and total force on particle and the reduce them to scaler value. But it seem there is a problem.

Hello,

I have a really quick question. I have a spherical region, and I want its radius to change with time. On this
link , you can find the following statement:

"The radius value for style sphere and cylinder can be specified as an equal-style variable. If the value is a variable, it should be specified as v_name, where name is the variable name. In this case, the variable will be evaluated each timestep, and its value used to determine the radius of the region."

Hello all,

I have modified LIGGGHTS with a custom fix, that modifies a per-particle scalar variable.
You can think of particles interacting with spacially varying radiation, where it is of interest, how much radiation dose each particle "collects".
To access per-particle properties has been easy, however, i needed an extra variable to store the radiation dose each particle gets.
The documentation suggests to create this via the fix property/atom as

Hello,

I try to mix sphere particles and multisphere particles in the rotray drum. The multisphere is consist of two adjacent spheres.

But in the simulation, some particles move strangely, which makes the rusults unreliable. When the drum starts rotating, an "explosion" occurs as shown in the attachment picture 1, 2 and 3. And during rotating, some paricles suddenly jump from the middle of the particle bed as shown in picture 4.

Hello,
I am trying to simulate the ANSI/ASAE S424.1 test. This uses a crank to wiggle and move screens.

I have the following movements
variable per2 equal 1./5 # 2.4
fix mv_box1 all move/mesh mesh BotShear riggle origin 0.125 0.0625 0. axis 0. 0. 1. period ${per2} amplitude 5
fix mv_box2 all move/mesh mesh BotShear viblin axis 1. 0. 0. order 1 amplitude 0.015625 phase ${phase} period ${per2}

Right now I am testing with with a shear box geometry to figure out the commands...

I am experiencing it "walking" in the negative y direction.

Hi

I need to find particles that contact with each particle in each time step as a list in my dump file.
Is there any compute syntax that can give me this array as an output?

Best regards

Hi,

Just beginning with LIGGGHTS, and I met a problem when I compile it.
The error information and the screenshot are attached. Is there anyone who could help me solve this problem?

Hello

Hi,
I'm pretty new to LIGGGHTS and I'm trying to incorporate heat transfer from an intruder placed within a granular system and the grains themselves.
The intruder is a simple creation and just made of a set of particles stuck together. So far I've only been able to set these particles that make up the intruder to an initial temperature that then cools as the heat dissipates into the surrounding granular bulk. But I want to fix the temperature of the intruder so that it remains at a constant temperature to assess how it dissipates heat through the granular bulk over time.

Hi!

Im using a contact model that does not include viscoelastic damping for normal contact (Thornton&Ning). I would like to be able to turn on contact damping. Is there some fix or way of adding viscoelastic contact damping or should I go into the code and implement it?

Thank you!

BR
Per