LIGGGHTS® - User Forum

Hello,

*This is a new version of an edited post because I originally thought this was a liggghts versioning issue, but it certainly isn't.*

I'm using this input data: https://1drv.ms/u/s!Am5GkbZS_98Xto1HN3LSdxzKI-x0fw?e=RBzhV9

Hi Guys

I am new to LIGGGHTS and and DEM analysis, my background is structural engineering and dynamics.
I would like to use LIGGGHTS to study a new type of vibrating screen which I am working on.

Current screens have either a linear, circular or elliptical stroke, with the stoke being constant at all points of the screen.
My proposed screen model will have a stroke which varies on various locations along the deck length.

Hello everyone, i´m studing of master in mechanical enginner and i very interested in the cpupling between DEM - SPH methods. I´m searching information about this topics and if possible this coupling winth liggghts-public.
Specifically, i´m interested do a simulation about a ball mills with water + solids.
i need know if this is possible do with liggghts-public.
i will be attent to comments.

regards

I spent a lot of time on this error but I could not solve it:
ERROR: Fix insert/stream (id ins): unknown keyword or wrong keyword order (../fix_insert_stream.cpp:151)

This my code:

#region and insertion
group nve_group region reg
fix ins nve_group insert/stream seed 49979687 distributiontemplate pdd1 vol ${alphastart} 200 region inbox

I attached the script, I need also help in defining the possible errors in this code I want to create the model shown in the attached figure

I am trying to use a adforce command to apply a stoke's drag force on a single particle using the following syntax

atom_style granular
atom_modify map array
communicate single vel yes

boundary f f f
newton off
units si
#region reg sphere 0.1 0.1 0.1 0.4 side out
#region reg block -0.05 0.05 -0.05 0.05 0. 0.15 units box
#create_box 1 reg
region reg block -0.005 0.005 -0.005 0.005 0.000 0.002 units box

read_data velo

#processors 2 2 1

I am using compute like this

compute kash all property/atom z

compute kashi all property/atom x

compute kish all property/atom y

variable b equal c_kash[1]

variable p equal c_kashi[1] #r

And I am getting an error "Compute used in variable between runs is not current. Use the update_on_run_end option for computes to avoid this". I want to Know how and where to use the update_on_run_end option. in Variable command or in compute command above variable.

Hello All, I have a question on fix move rotate command in LIGGGHTS. Setup has a drum made up of particles, closely placed so that there is no gap.

I'm first using
fix wall particleWall freeze to freeze particles and then using
fix particleWallRotate particleWall move rotate 0.0 0.0 0.0 0.0 0.0 1.0 0.05 to rotate wall with a constant period of 0.05 sec.
This is working okay.

Hello,

Can anyone please show how to set liquidsource and liquidflux with washino/capillary/viscous, i looked everywhere but i found nothing.

any ideas ?

Regards.

I am using a If command (if "${b} <= ${bod1}" then "variable bod1 equal v_b") and getting an error (Compute used in variable between runs is not current. Use the update_on_run_end option for computes to avoid this.) I am trying to define update on run. when i try to do that they say illegal variable command. how and where to define update on run in variable defined in if command. I have defined variable like this (variable bod1 equal 1e-5) (variable b equal c_kash[1] ) (compute kash all property/atom z ). Can you please help me editing these commands to get rid of an error.

Hello everyone!! I am a new to liggghts and have installed and successfully running my simulation. The only issue is that liggghts uses 1 by 1 by 1 mpi grid set up even though I give command mpirun -np 8 .................
I am using Ubuntu 18.04 on a 12 logical core system. Someone please help.