LIGGGHTS® - User Forum

Dear Forum,

I was wondering if it is possible to make DEM simulations while some particles are steadily expanding at a given rate. Should it be enough to mark the particle radius as a variable and make it evolve with time?

Regards,

Oier.

Hello Everyone,

I have a query regarding the simulation I am doing right now regarding slurry flow (carbon particles moving in a flowing water) in a microchannel to simulate charge transfer between particle-collector and particle-particle.

Hi
How can we insert single geometry multiple times, also how can we control their orientation.
You will get more idea about the problem in following video links:
https://www.youtube.com/watch?v=FmAm6QoXeB8
https://www.youtube.com/watch?v=9A5n6p4OmaE

Dear LIGGGHTS experts
I have just started using Liggghts and have two questions regarding the bod models:

(1) Like elastic bonds, can we also model plastic or elastoplastic bonds between the atoms. A typical bi-linear elastoplastic stress strain curve is attached.

(2) Can we model cohesive-zone based bond failure, an example traction-separation curve is attached.

Thanks

Hi
I am a novice to LIGGGHTS.
I am wondering ho I can apply beam boundary conditions on selective particles, such as shown in the video in the following link
https://youtu.be/I01tRnfdZ30

Thanks
Shubham

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.