LIGGGHTS® - User Forum

Hello,
I was going through the source code and came across this function, and I was looking to see if there was any more information on it.
I was able to get it to work and it does what I have been using MATLAB to do.
I am working with the bond/gran model and have been using MATLAB to spawn in my fibers.
However, the fix_template_multiplesphere function is doing (almost) what I want.
I say almost because it seems that the code is only checking if "starting node" of this template is inside the boundary

Hello people. I made another thread in developer forum, asking how to get the force in a simulation using granular bonds. The problem is that the values shown in dump files, aswell as the values calculated with compute property/local are way low than they should be (for the example i uploaded it should be around 31N, and its showing in both cases something close to 1e-6).

I tried running the simulation at 64, 128 and 256 cores, with the same in file and the executable. The simulation works fine for 64 cores but when we run it on 128 and 256, the particles seem to fly out or seem to be get deleted somehow.
I hope someone could give me an insight about this.

I have attached the in file, the only difference between the 3 being the number of processors.
64 cores -processors 16 2 2
128 cores -processors 32 2 2
256 cores -processors 64 2 2

Also attached is the final image of the simulation.

Hello.

I am trying to simulate granular flow using LIGGGHTS.

In my simulated scenario, almost all particles are concentrated in the lower right corner of the boundary region, so the load would be not balanced if we simply divided the domain equally. Therefore, we need to modify the divided domain according to the distribution of the particles, e.g., allocating more worker processes in the lower right corner.

Greetings, i recently finished a simulation in LIGGGHTS 3.6, but when i try to post processing the information using "lpp", the process freezes. I use the cpunum command in order to reduce the cpu cores, but it still freezes and no error message is shown. I'm still waiting for restarting of the process, but it has passed more than 7 hours and nothing happen.

I add the lines from my console.

Hello to everyone

Is there a way to work with cuda processors to run a simulation in LIGGGHTS?. I have a Nvidia Geforce GTX 960.

Best regards.

Nicolás.

Dear liggghts users,

I want to set up a simulation with bonds (I am using liggghts-with-bonds) that has atoms with different sizes. I was not able to get different atoms with the „create_atoms“ command.

My idea was to first insert the atoms with the fix insert/pack command, let them settle and then create the bonds in order to have bonds and different sized atoms.

Hi there

Is it possible to calculate the force acting on the mesh/surface?

In my simulation, I use the fix top all mesh/surface/stress/servo file bottom.stl type 1 scale 0.03 move -0.015 -0.015 0.1 com 0. 0. 0. ctrlPV force axis 0. 0. -1. target_val 0.0003467 vel_max 5e3 mode auto ratio 0.01 to cap the particles. how can I manage to know the force on the mesh? because I suppose this command will set the wall compress the particles by 0.0003467N.

Thanks
Weijing

Hi,
i m working on mult-isphere particles mixing in cylinder . problem with my simulation is that some of the particles remain suspended during insertion and stick with impeller rod. if there is anyone who can help me out. i m uploading a picture of my problem. please help me.

thanx

Hello,

I am new to LIGGGHTS, so I tried to modify a tutorial example for a granular flow to create a 2D Couette flow. This is the example I am modifying:

https://www.cfdem.com/media/DEM/docu/Section_input_script.html#an-exampl...

I have got so far with the modifications, but I hit a problem. When I try and convert the dimension to 2D using this line:

dimension 2

The error message appears: