LIGGGHTS® - User Forum

Dear all,

I am facing a problem about saving the maximum of contact force.
I first get the pair-force with:

compute fc all pair/gran/local force
variable fmag atom sqrt(c_fc[1]^2+c_fc[2]^2+c_fc[3]^2)
compute maxfmag all reduce max v_fmag
variable maxcm equal c_maxfmag

There seems no mistakes while operating the above code, however, when I tried to output the result using:

fix data_max all print 10000 "The maximum of contact force = ${maxcm}" file data.txt

Hi guys!

I'm planning to assign material properties ( density, charge, youngs modulus etc.) to the meshes so that meshes can interact with the particle.

Eventually, I want my meshes to have Coulomb force and contact force with the particles.

1. If I use 'fix cad all mesh/surface file mesh.stl type 1' then imported mesh have the material property of atom type 1?

2. And if I want to assign material property different from the particle, then how can I assign it?

Dear all,

I have output the vtk. files of force chain and applied them in Paraview using the following two commmands:

compute cpgl all pair/gran/local pos vel force force_normal
dump dmp2 all local/gran/vtk 100 post/forcechain*.vtk cpgl

Dear
I am using the ubuntu that brings window 10 and I want to load LIGGGHTS, Ubuntu works fine but only in terminals. Someone has some procedure to load LIGGGHTS in this environment.
I'm new to this from loading the program.
Thank you
Alejandro

Hi,
I'm trying to superpose two move/mesh rotate commands. The application is like a robot arm with two parts and the rotation axis of the second part changes with the movement of the first part.
The manual says, that for style rotate, the origin of the rotation axis would be in local reference, if there is a move command before. I think, however, that the vector of the rotation axis always remains in the same direction. Is this correct or is there a way to change the vector of rotation axis, according to a move / mesh command before it?

hi,
i m using a cylindrical mixer. i want to extract my data along a line probe. when i select plot over line it gives me results of two points not all particles on that line or probe. basically i want to extract a data w.r.t to x-coordinates. can anyone help me how to get a data of points along a line

When I run the provided examples, I can successfully output dump files, but I would like to visualize the simulation in Paraview. When I use custom/vtk to output vtk files, I get the above error message. I recently installed VTK and turned USE_VTK to "ON" in the Makefile.User. Has anyone else had this problem/how did you resolve it?

Thanks,

Jackson

Hey there,
I used the following commands and received the output files but i dont know how to post-process them.

compute CON all contact/atom
dump cn all custom/vtk 100 post/coornumber*.vtk id x y z c_CON

Should i use Paraview, MATLAB or sth else?

Hi, everyone,

I am working on mixing of granular particles in a cylindrical bladed mixer. I want to create force chain network as like given in the attached picture.
would you help me to create the contact force chain structure like that? how to get output from liggghts to built this structure.
thanks in advance

Hello,

I am trying to simulate the angle of repose of alumina. A picture of the simulation I am performing can be seen in the Figure attached. It is a funnel unloading alumina directly in the floor, and after a certain amount it should stabilize and one could get the angle of repose.

However, I am facing a weird behavior. After stop inserting particles, the pile of alumina (which until this point seems to have a correct angle of repose) suffers some instability and collapses a little bit, affecting the angle of repose.