LIGGGHTS® - User Forum

hello everyone,
I wish to simulate one system where particle(sphere or multi-sphere) breaks when it attains some certain height. can anyone please help me with some suggestion? I was going through multisphere/break, but could not figure out threshold value.
any suggestion will be highly appreciated.
thanks in advance.

I know I've discussed this at some level before but, Richti, it sounds as though you've run large simulations with your bonds package with multiple processors? I seem to get intermittent errors when I try to, for example:

Dear all,

I want to use the servo wall (cap) to close a pipe. The granular material in the pipe will built up a pressure on the servowall so that the cap open at an predefined force value. So i need the servo wall to stop at the ending of the pipe.
I specify the servo command as followed:

fix cap all mesh/surface/stress/servo file meshes/cap.stl type 2 com 0. 0. 0. ctrlPV force axis -1. 0. 0. target_val 1 vel_max 0.1 kp 5.

is there a command to stop the wall at a specified coordinate in moving direction of the cap?

Best Regards

Hello,
I am trying to do a triaxial test using LIGGGHTS-WITH-BONDS. I have never really used this software before and I am struggling in understanding what the parameters mean. The particles are in a box were one wall is applying pressure through the mesh/command/stress/servo code. I am trying to calculate the stress the particles are causing on the other walls and my input parameters are as follows:
Minimum ball size -2.5e-4 m
Maximum ball size -4.5e-4 m
Density -2650 kg/m3
Ball and bond elastic modulus - 40 e9 Pa

Hello everyone

I have created a sieve through which particle can pass through (sieve size 75 micrometre) .But when I run the simulation in LIGGGHTS the particles (particle size 50-100 micrometre) does not pass through the sieve instead they settle on top of sieve. Can anyone suggest any method to sole the problem.

Thanks in advance
Jyothish

Hello,

I want to simulate powder auger dosing of particles with size around 600-800 µm.
The problem is that the particles are sticking to the auger and not flowing down. I changed a lot the parameters of the friction, cohesion and rolling friction and still didn't work. What could be the problem?

Attached are some screen-shots of the input script and the problem occuring.

Could you please suggest some tips for a solution?

Sorry for the trivial question, but I am new and I am not able to install LIGGGHTS on my Windows laptop. I tried to follow the instructions written here: https://www.cfdem.com/media/DEM/docu/Section_start.html but I they are not very clear to me. Can anybody help me? Any advice will be useful, thanks.

Dear all,

Dear all,
I am a new user of LIGGGHTS and still learning it. Meanwhile, I saw an image of icing on a substrate simulated using LIGGGHTS code and posted as an application example on the CFDEM website. Currently, I am working on a student project related to freezing of supercooled water droplets.

I would like to ask you whether there is any documentation or tutorial of these icing example. I would really appreciate if anyone could help me on this aspect. Definitely, I would cite the code properly when I would write the student project report.

Hello Every one,

I am having a problem understanding how to define "vec_side" with "count multiple" in fix massflow/mesh command.

I tried every thing I could think about to determine the vector components defining the “outside” of the mesh but I keep getting the error:

ERROR: Fix massflow/mesh (id massflows): requires a planar face mass flow measurement or using 'point_at_outlet' (../fix_massflow_mesh.cpp:344)