LIGGGHTS® - User Forum

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

I try to visualize the speed of a running solver. To do this I want to dump into a CSV file for example the elapsed time since the first run and the current time steps. This CSV file can be visualized and periodically updated (e.g. with gnuplot or LiveGraph) to estimate the required time to finalize the simulation and to see the change of the simulation speed.

Hej guys.

I need to use the "move/mesh mesh cad rotate/variable" command because I can spezifiy angular velocity.

My problem:
A)
variable omega equal 2
fix bewegung all move/mesh mesh cad rotate/variable origin 0 0 0 axis 0 1 0 omega ${omega}

B)
variable omega equal 2
fix bewegung all move/mesh mesh cad rotate/variable origin 0 0 0 axis 0 1 0 omega omega

C)
fix bewegung all move/mesh mesh cad rotate/variable origin 0 0 0 axis 0 1 0 omega 2

Hi everyone,

We are attempting to install LIGGGHTS in ALTIX ICE 8400 EX SUPERCOMPUTER

Hi,

has someone an idea how to fix this problem?

My challenge is it to move a wall/gran/hertz/history (complex geometry) through a region full of particles to compute the resulting force onto the wall.
I need the force for further calculations in MatLab.

Some ideas?

Regards
hansmannb

hi,
i am working on finding the porosity of soil , in that
my volume of the atom or grain changes at certain
timestep. i want to know how to compute the changing
volume in liggghts ?
thanks in advance,
Dixon