LIGGGHTS® - User Forum

Hi all,
I am writing-up LIGGGHTS tutorial for beginners. Pleas suggest me to improve. Tutorial attached herewith, plz download and see.
Thanks
RC

Hi all
I want to stop a belt conveyor. I tried to unfix a "mesh/surface" and then fix it with a new surface_vel, but an error message shows up.

here is my in file:

Hi all, I set the units system to be si in the beginning.
Later I used fix mesh/surface/stress and export the pressure/shear/stress by dump mesh/vtk.
what's the unit of the output??? the pressure, shear, stress components??
N? Pa? kPa??
I am not sure.
thanks for help

Regards,
Xiuhan

Dear Friends,

I have a few questions about valid input geometries for LIGGGHTS.
What kind of geometries can LIGGGHTS handle? What softwares can create these kind of files?
I have Gambit, Maya, Autocad on my pc. Are there any tutorials for building geometries for LIGGGHTS?
Should I mesh the geometry and export it to LIGGGHTS?

Regards,
Shahab

Hi everyone,

I have one question about cofficient rolling friction. In my case, I used three different material, called type 1 type 2 type 3. the particles (type 1) alway roll a long time to stop on the plane (type 3). the different rolling frictions from (0.1-10) were tried, But still have the same issue.
the following is the line:

fix m5 all property/global coefficientRollingFriction peratomtypepair 3 0.75 0.1 10.86 0.1 0.65 0.59 10.86 0.59 0.65
pair_style gran/hertz/history rolling_friction cdt #Hertzian without cohesion
pair_coeff

Hi, I along with Christian Richter have re-added the fix breakparticle/force feature in LIGGGHTS 2.3.8. The modified repo can be clone from https://github.com/rahulksoni/LIGGGHTS-PUBLIC

The repo contains a breakparticle example and a successful animation of it can be found at https://www.youtube.com/watch?v=QM4JYtjU8v0&feature=player_embedded

Please have a look and suggest for improvements.

Hello Everybody,

I have a problem with this Error: "Use of region with undefined lattice " ;-)

I want to create a region defined by a VTK-Mesh. Unfortunately i can't read the VTK with the following command: "region myreg mesh/tet file test.vtk scale 0.001 move 0 0 0 rotate 0 0 0" I generated the mesh in NETGEN from a step-file. The same Error appears if I change the name of the file to test2.vtk so LIGGGHTS can't find the file. Am I doing something wrong or is there a bug in LIGGGHTS? I attatched the vtk file.

Greetings
Hendrik

Hi,
I want to start dusty plasma simulation. Is there a way to perform such type of simulation using liggghts (or with CFDEM)?
Thanks in advance for help..
Ram

I was wondering if anyone can explain more about the "history", "periodicity flag" and "triangle id" in compute wall/gran/local command and also how mesh id and triangle id are different from each other. I also need to know if there are 17 output values(in total) for this command or, if there are more than one value for history. I am using "pair_style gran/hertz/history rolling_friction cdt".
any answer is appreciated.

Cheers,
Mahsa

hi,
i want to calculate the volume change according to the change in the diameter of the particles but
i cant able to use the atom style variables in the calculation.

i cant able to use the variable radi for the formulation of the volume and i am getting an error saying
ERROR: Per-atom compute in equal-style variable formula (variable.cpp:895)

variable vtotal equal 1^3
variable vp1 equal ${radi}^3)*3.1415/4
print ----- ${vp1} -----
variable n1 equal (${vtotal}-${vp1})/${vtotal}
print "## quit"
quit