LIGGGHTS® - User Forum

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

pair/gran/local - error while using the "contactPoint"

Submitted by Khan on Fri, 01/10/2020 - 05:48

Hi Everyone!

When i use the "compute pair/gran/local" using the following:

compute cpgl all pair/gran/local pos id force contactArea
dump dmp_cpgl all local 1000000 output/fc/cpgl*.dump c_cpgl[1] c_cpgl[2] c_cpgl[3] c_cpgl[4] c_cpgl[5] c_cpgl[6] c_cpgl[7] c_cpgl[8] c_cpgl[9] c_cpgl[10] c_cpgl[11] c_cpgl[12] c_cpgl[13]

The above works perfect for me!

However, if i would like to know the coordinates of the contact point at which the force is calculated, i need to use the following:

Post processing / Rendering multisphere particles

Submitted by Michelle Phan on Fri, 01/10/2020 - 00:12

Hello everyboday;
I am working on irregular particles. I clumped the particles together by the fix multisphere command. I use Paraview to visualize the irregular particles but the rendering image is not good. It is hard to see the shape of particles. I am wondering if there are plugin of Paraview or other programs that can help me to visualize the shape better?
Thank you

Skip particles during computation

Submitted by amgroen on Thu, 01/09/2020 - 17:38

Is there a way to have a group of particles being skipped by collision detection and locked in place, ideally while reducing the computation time.

A simulation that I'm running involves filling a tall cylinder with particles and I want to ignore the majority of them and only freeze a certain distance from the top for the next layers.

Simulating the entire stack is not feasible computation time wise on my desktop.

I haven't been able to find functionality like this in the documentation

Thanks,
Alex

Changing the environment

Submitted by PRATBHARAT94 on Mon, 01/06/2020 - 21:34

Hello,
I am very new in the field of LIGGGHTS. I have already installed LIGGGHTS 3.7.0 version. But I have to work with atom type superquadrics , I have installed the version 3.8.0 too. But while I am simulating the case. It was creating the 3.8.0 version environment. Please tell me how can I change the environment??
Thanks in advance

Mass_Temperature for fix mesh/surface

Submitted by amanr on Mon, 01/06/2020 - 12:45

Hi,
I am trying to simulate a cold hollow sphere mesh surrounded by hot particles. I am using the mass_temperature tag for this, but when I dump the mesh temperature, it doesn't change with time even though the surrounding particles are at a higher temperature than the mesh. Does anyone have any idea if this feature works in LIGGGHTS?

syntax used:

fix cad2 all mesh/surface file Indium226mm.stl type 2 move 0 0 0.007 temperature 300 mass_temperature 0.35

dump meshtemp all mesh/vtk 500 temp*.vtk temp cad2

Thanks!

Forming Bonded Conglomerates

Submitted by driley on Fri, 12/20/2019 - 18:14

I am trying to generate a relatively large number of bonded conglomerates. However, I need the individual conglomerates to remain unbonded from each other. Is there a way to read in a text file with a specified bonded conglomerate in a way similar to multisphere? Or perhaps define bond creation based on material location at a given time step?

Velocity vector on boundary

Submitted by jagan1mohan on Wed, 12/18/2019 - 07:26

Hello Team,

Greetings. I'm using move/mesh fix to rotate a boundary (something like cylinder (top.stl, bottom.stl, curved.stl) filled with particles). Can we plot / extract velocity (mag) or velocity vector on the curved.stl boundary and view in post-processing? I'm using paraView and can create a glyph for particles but not for this surface?

Any method exists to export data on *.stl boundaries?

Thank you,
Jagan Mohan.

Temperature-Dependent Variables

40044600's picture
Submitted by 40044600 on Sat, 12/14/2019 - 19:58

Hello,

I am seeking to set up my simulations to allow for particles to have a certain cohesion factor dependant on their temperature.
I have seen from a previous post in 2011 that this is not a trivial thing to achieve but may be possible with some build around python coding.

I'm hoping someone could guide on a structure of things that need to be achieved in order to allow for temperature-dependent variable to be achieved.

Thanks

Pages

Subscribe to RSS - LIGGGHTS® - User Forum