LIGGGHTS® - User Forum

Hey all,

I have got a 2D-array of different values for a force field depending on the region from another program (matlab) in a txt.file (other files are also easily possible).
I want to add these values via the addforce command to the particles in my simulation.
Depending on the position of each particle, it should give me an unique forcevector.

Hi all,

I have try to use the 'fix mesh/surface/stress/servo' to apply confining pressure on each sides of a cubic box. (100mm*100mm*100mm)

I want to apply 200kPa confining pressure on each sides with the following command. Take the left side as an example

fix zservo2 all mesh/surface/stress/servo file meshes/rwall4.stl type 1 com 0. 0. 0. ctrlPV force axis 1. 0. 0. target_val 2000 vel_max 100. kp 1e-2. ki 0. kd 0. #left

Hi guys,
I am currently using Red hat .
I tries to compile LIGGGHTS(3.5.0) by using make fedora but error occurs as follows :

/usr/bin/ld: cannot find -l-lsundials_cvode
collect2: ld returned 1 exit status
make[1]: *** [../lmp_fedora] Error 1
make[1]: Leaving directory `/share/apps/LIGGGHTS-PUBLIC-master/src/Obj_fedora'
make: *** [fedora] Error 2

so I tried make spirit instead of make fedora but it gets the same error :

hi to everyone

can any body tell me is there any command that must be used for different size particles ?

Hi,
I am using liggghts data for a macro-scale simulation, where there is aggregation happening leading to increase in the size of the particles. I want to restart the simulations from the previous state but with the new particle sizes. Is there a way to achieve that. Merely changing the sizes in the new infile leads to an insertion error.

Thank you for your help!

-Chai.

aoa

particle are not mixing like discrete . they move like chunk and do not mix properly ... i m uploading my input file plz help me because i have to submit my work this week. i m uploading a pics and code

#Poly dispersed flow

atom_style sphere
atom_modify map array
boundary f f f
newton off

communicate single vel yes

units si

region cyl cylinder z 0. 0. 0.075 0. 0.320 units box
create_box 2 cyl

neighbor 0.003 bin
neigh_modify delay 0

#Material properties required for new pair styles

Hello,

I want to determine average of velocity square < (Vx^2) > and later average it in a band at different heights in the domain.
I tried to do so in the following way using variable and fix ave/spatial command.

variable gvx equal vx*vx
variable gvy equal vy*vy
variable gvz equal vz*vz
fix gvel all ave/spatial 1 1000 1000 z lower 0.01 v_gvx v_gvy v_gvz file meanv.txt

Hi all,

I have seen the LIGGGHTS v3.x doc about the command 'fix insert/pack'.

For the restriction, it says "The overlapcheck = ‘yes’ option performs an inherently serial operation and will thus not scale well in parallel. For this reason, if you want to generate large systems, you are advised to turn overlapcheck off and let the packing relax afterwards to generate a valid packing.".

What exactly I have to do to let the packing relax afterwards? Thanks.

Regards,
Josh

Hello!

Hello everyone,

I wanted to have the coordination number in my simulation and used the following codes in my simulation:

compute CN all coord/gran
dump cn all local/gran/vtk 100 post/coordnumber*.vtk CN

But it didn't work. Can you see any problem with these 2 lines?
Thanks