LIGGGHTS® - User Forum

Hi, I am doing simulation in rotating drum.
My rotating drum rotates for 60 sec and per rotation is defined as 4 sec.
i.e I am going to have total 15 rotaions.

Right now I am saving whole simulation in a single folder.

For some specific tasks, I need information from each rotation.

Is it possible to save dump files based on each rotaion?
e.g. : for 15 rotations, I would like to have 15 folders with corresponding files from each rotation.

Any help would be appreciated.

My main question here is: should the simulation results be dependent on the values chosen for the neighbor page and one settings?

My neighbor settings are set as follows with the skin set to the diameter of the biggest particle in my simulation, and my particles are uniform or in some cases have a small range of sizes:

neighbor ${maximum_particle_diameter} bin
neigh_modify delay 0 every 1 check yes page 100000 one 2000

Hello LIGGGHTS experts,

I am working in the field of particle dampers and I am very new to the LIGGGHTS world. Therefore, it would be great if I can get some help from the LIGGGHTS community.

I have attached the figure of the Spring-dashpot system, which I am trying to simulate. My question is how I can model the Spring and Dashport, which are connected to the box in LIGGGHTS?

Thank you for your Help.

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.