LIGGGHTS® - User Forum

Hello,

How can I enable torsion torque for a primitive wall? Please see the error below. The ordering works for pair_style, but not for wall/gran. Thanks!

fix wall_z1 all wall/gran model hertz tangential history cohesion sjkr rolling_friction epsd torsionTorque on primitive type 1 zplane 0 # floor
ERROR: Fix wall/gran (id wall_z1): Unknown argument or wrong keyword order: 'primitive' (../fix_wall_gran_base.h:131)

% script, up to error

Hi,
When i am trying to open pdf it showing 'Page not found' so is there any solution to this?
Regards,
Kavya

I had LIGGGHTS working on my Ubuntu 20.04 system. The machine automatically updates to 22.04, and now I am unable to compile with make auto command. I get the following error:

Hi,

In my simulation a disk is rotating around its own axis while translating and where a small part of the disk is submerged within a bed of material.

For my research I need the torque output on the rotation axis. However, when outputting the torque on my rotating disk in a .csv file, I get a sinusoidal torque for each component X,Y,Z, (see picture 1) which is not what I would have expected beforehand. Especially because it moves through 0 meaning my particles give the disk a 'push' at some points in time. Some directions:

Hello everyone,
I am learning how to do simulations by Liggghts. Now, I want two kinds of powders to fall onto the bottom of the domain. But it showed that my particles directly went across the domain and disappeared. I tried to decrease my time step to 1/10, but the problem was still unfixed. Could anyone please help me to deal with this problem? The input script is below. Thanks very much for your help.

atom_style sphere
boundary f f f
newton off
atom_modify map array

communicate single vel yes
units si

processors 2 1 2

Hello,

I have a single particle resting on a plane which I then set spinning. The particle experiences a constant angular velocity, despite an opposing torque (attached plot). I create the particle on top of a primitive wall and allow it to settle before setting omega_z to 1 m/s. With rolling friction (EPSD) on, there is a small but constantly decreasing z torque, however the particle's omega_z remains at 1m/s. What to do I need to fix about my script (attached) in order for the particle to see a decrease in angular velocity over time? Thanks!

Eric

I am working on a standard hopper discharge simulation to create a basis for some future work in my program. In trying to learn LIGGGHTS by itself, I am able to create particles and load the "STL" file for the hopper mesh, However, when I run the particles, there is no contact detection it seems between the particle and the mesh wall supplied.

Do you have LIGGGHTS code, geometry and meshes for triaxial tests? If you have, could you please share with me? I am learning the LIGGGHTS to simulate the triaxial test. It would be a great help if you could share it with me.

My email is ripon120535@gmail.com

Thank you very much.

Hi, I am trying to add the Thornton and Ning contact model to LIGGGHTS-WITH-BONDS developed by richti. There are just way too many errors when compiling and I am unable to figure out an elegant way to add the Thornton and Ning model (from normal_model_thornton_ning.h in LIGGGHTS-PUBLIC-master) to LIGGGHTS-WITH-BONDS. Can someone please help?

Hello everyone,

i wanted to write the temperatures of the particles in a certain region into a text or csv file. Getting the mass, the number or other many properties of the particles in a certain region is possible easily with region functions, however i could not find any region function with temperature. For example for mass i wrote this and it works.

variable m1 equal mass(all,outlet)
variable t equal step*dt
fix data all print 100000 "$t,${m1}" file ../DEM/Messdaten/mass.csv title "Zeit(s),Masse_in(kg)"