LIGGGHTS® - User Forum

LIGGGHTS® related topics can be discussed here: discussion about models, installation, feature requests and general discussion

LIGGGHTS-PUBLIC and non-uniform domain decomposition.

mdasilva's picture
Submitted by mdasilva on Sat, 08/12/2017 - 18:42

Is it possible?

I've been reading the code and LIGGGHTS-PUBLIC uses a uniform domain decomposition, on the other hand there are some pieces of code showing it could, eventually, support this kind of domain decomposition (for instance, the Comm class has a public attribute called uniform and the comments make one think it's for non-uniform domains).

Greetings,
Miguel.

dump scaling status unknown

c.beaulieu's picture
Submitted by c.beaulieu on Thu, 08/10/2017 - 22:43

Hello,

I am working with LIGGGHTS 3.5.0 and I modified my dump files so I get a new line in the header with the timestep of my simulation (see below). It is easier for my postprocessing where a Python program comes and reads directly my timestep.

dump final all custom 1 postLoading/drumLoadingFinal_*.dump id type x y z vx vy vz fx fy fz omegax omegay omegaz radius density
dump_modify final pad 8 sort id label TIMESTEP_${timestepPerso}

SINGLE PARTICLE

Submitted by govind on Thu, 08/10/2017 - 14:00

I want to generate single particle with large radius like a tennis ball. I am trying with given command of particle distribution but not getting success.
Actually I have task to impact a large size particle into the pool of smaller particles (big particle size is more than 20mm and smaller particles have size around 2mm).

Is this okay if instead single particle I use cad stl file of sphere? I tried this also but as stl(sphere) falls domain boundary stretches , I can not use fixed boundary as in this case particles get lost.

Please tell me how do I proceed?

Simulating biaxial rotation of mesh

40044600's picture
Submitted by 40044600 on Wed, 08/09/2017 - 09:36

I am having difficulties trying to simulate biaxial rotation of an imported mesh.

I am looking the simulate the motion which occurs during rotational moulding where the mould (mesh in this case) rotates around two of its axis.
The current rotation commands within LIGGGHTS that I've found allows rotation to be set to the coordinate system in space but not to the mesh itself, which is where my issue lies.

Error in loading mesh

Submitted by z3490628 on Tue, 08/08/2017 - 12:26

Hi all,

I am new to this software. I am hoping to create a 100mm*100mm*100mm cube box with spheres inside the box and then applying confining pressure on all sides.

I have tried to import a mesh created from AutoCad (using other computer and copy back to my own computer) using the fix mesh/surface/stress/servo.
However, some errors are happened and the script is terminated.

Can anyone help with this? I have attached with my script. Many thanks.

Josh

How can I add new pair style?

Submitted by fabregas04 on Mon, 08/07/2017 - 14:20

Hi guys,

I want to add new pair style from the LAMMPS to the LIGGHTS.

So, I just copied .cpp and .h file to the src folder in LIGGHTS.

Then what should I do to recompile the LIGGGHTS?

I need specific description for recompiling. (I'm using LINUX)

Please let me know how to recompile the LIGGGHTS.

Finnie wear by single particle impact?

Submitted by -Hauke- on Fri, 08/04/2017 - 14:38

Hi All,

I am running a simple test case by shooting a single particle on an impact plate using different impact angles, velocities and mass.
At all the dependencies of the velocities and the mass are like expected. I just struggle with the results of varying impact angle, because in my case it doensn´t fit with the theoretical results i would expect by finnie. I attached a picture of the results of the simulation for the wear after impact and the curve i would expect for varying impact angles.

bond coefficients

Submitted by rob1 on Thu, 08/03/2017 - 13:23

Hello,

I am trying to simulate the interaction (hertz) between a stl mesh (type 2) and an ensemble of particles bonded together (type 1).
I am using:

atom_style hybrid bond sphere
...
pair_style gran model hertz tangential history
pair_coeff 1 2
bond_style harmonic
bond_coeff 1 1000.0 200.0

Why do I get errors in the bond_coeff command? E.g. index out of bound or incorrect args for bond style (if I insert * instead of 1).
Thanks a lot and have a nice day,

rob1

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