LIGGGHTS® - User Forum

Dear LIGGGHTSers,

What is the reference for the Hooke/hysteresis model implemented in the NORMAL_MODEL_HOOKE_HYSTERESIS.h? i cannot find it in the documentation. Is it the Linear Elastic-palstic Ahhesive model (Luding 2008)? Thank you.
Best regards,
Zyan,

Hi,

I am trying to use IF command and I getting this error "ERROR: Unknown command: { (../input.cpp:293) "
if "${typ1atoms} == 0.0" then { variable velcity1 equal 0.0 }

Can anyone please help me?

Thank you.

Is it possible to have access to the STL file used in LIGGGHTS_Tutorial.pdf, I mean STL files of Shear Cell or other examples?

Thanks

Hello everyone

I am pretty new to LIGGGHTS and DEM simulations. I am trying to model a wet granular system. I want to know if LIGGGHTS has the equation of interparticle force of the capillary bridge for simulating wet granular systems?

Regards

Halimeh

Hello,
When i use the command "fix...addtorque" to add torque to one particle, it happens an error " invalid fix style: "addtorque" " . Did anybody encountered this kind of situation?

thanks

Hello,
I want to limit particle rotation strictly,but i can no find relative command in liggghts.Have anybody used this command?

all thanks
K.cheng

Hi,

I am looking for a way to write particle-fluid interaction force of specific particle to a file. Normally I use Fix/print to output other information of atoms such as id,x,y,z or fx,fy,fz by pre-defining variables. However for dragforce, I am confused how to define variable for it.

For example one of my trials and it was failed below.

variable ID equal f_dragforce1[id_of_particle]

The structure of dragforce array might not be the same as those of normal force, fx,fy,fz in which we can point, e.g, fx[id_of_particle].

I'm running a sim on a PBS server, so in order to try to save cluster resources, I'm trying to get my sim to quit when all the particles have drained out. Therefore, I have a run every command that looks like this:

run 20000000 every 500000 "if '$a < 1' then 'quit'"

where $a is my particle count

this only gives me "substitution for illegal variable" errors. I've tried everything I can think of, and I get an error messege every time. What am I missing?

Hi everybody

I am trying to make a complex shape particle by using fix rigid molecule command. I used following scripts in lammps and it run well. but once I wanted excutive it in liggghts I saw this ERROR: Illegal fix property/atom command, not enough arguments (../fix_property_atom.cpp:65)

units si
atom_style sphere
boundary f f f
newton off
communicate single vel yes

fix addMolecule all property/atom mol ghost yes
read_data mybag.rigid fix addMolecule Null Molecules

Hi all,

I am trying to import particle positions through the read_data command. I have 10.000 particles that appear in the first time step and apparently all the input file is set ok.

It starts running and after a while the simulation stops saying the process has been killed.

Is it because there are too many particles to be inserted in 1 timestep? I previously tried to insert them all at once through a fix command but I had the same error message. I tried a different insertion methods (not in 1 timestep) afterwards and worked fine.