LIGGGHTS® - User Forum

Hi all,

I have a simulation in which I calculate the average per particle force and use it to control the sim, i.e.

compute avg_f all reduce ave fx fy fz
variable mag_ave_f equal sqrt(c_avg_f[1]^2+c_avg_f[2]^2+c_avg_f[3]^2)

Hi,
Is there any way to dump force (weight) on wall of container due to all particles (if I dont want to use mesh)?
Thanks in advance,
Ram

Hi everybody,
The output file of the following programme dumps lot of zeros even in atomic ids.
Could you give some explanation?

###### programme starts here ##########
units si

atom_style granular
atom_modify map array
boundary f p f
newton off

# Read data
read_data Ordored_Liggghts_long.sys

set group all diameter 0.10

communicate single vel yes

neighbor 0.001 bin
neigh_modify delay 0

#Material properties required for new pair styles

Hi everybody,
I am making a packing from the standard read_data file in LIGGGHTS example. The particles are falling under gravity.
I am facing problems similar to the particles disappear problem at node/456

I have also increased the spacing of wall to avoid touching with the wall. But the particles are disappearing faster with this.

Disappearance starts when there are many neighbors.

Any comments...

Best regards,
Samantaray
###################################
read_data file: Ordored_Liggghts_long.sys

LIGGGHTS Description

Hi everybody,
I think there is a minor bug in the output of make package-update and make package-status on GRANULAR package in liggghts_1p4p6. Though it is installing the GRANULAR package the screen output of package-status and package-update says otherwise.

The output are given below.
regards,
Samantaray

$ make yes-GRANULAR
Installing package GRANULAR

$ make package-status
Installed NO: package ASPHERE Installed NO: package CLASS2
Installed NO: package COLLOID

hello all.

can anybody help me how to rebuild liggghts with all the packages.
i followed this way:
make yes-all
make packages-update
make clean-all
make fedora_fpic

but this is giving errors. these errors have deleted previously build executable lmp_fedora_fpic. im not getting what to do now.

thanks for any reply

Hi all

In the LIGGGHTS doc I've read about modeling a rotating container using the rotate keyword. I'd like to rotate a container with one particle inside. For more details I've adhered the in.rot file. My questions are:

1) Why do I need the lattice command for rotating?
2) What changes are necessary that the particle can move free and falling down under gravity?
3) Is it sufficient modeling the container just with the simulation box?

hello all,
I am new on liggghts as well as Cfdem. i have installed Openfoam, liggghts and cfdem on ubuntu-10.04 LTS as per guidance in the installation text file given on this website. to learn liggghts properly i chose 'packing' example given in LIGGGHTS and i entered following commands in terminal:

cd LIGGGHTS/liggghts_GIT/example/LIGGGHTS/packing
cp ../../src/lmp_fedora_fpic .
lmp_fedora_fpic

i have 3d cavity case , and i want to have a middle section on x direction
suppose the section is 2d plane
i need to have as out put :
lattice ID on Y || lattice ID on Z || averaging spatial velocity on X ||
how can i do this .. since fix/ave give layers averaging and not lattice by lattice !!!
thankx

Hi everyone,

I'm now trying to press a packing by a meshed wall to reach a specific force. But it's always error and I don't know why. May anyone have a check and give some hints for me? The commands I use is as below:

fix topwall all mesh/gran/stressanalysis topwall.stl 1 1. 0. 0. 0. 0. 0. 0.
fix F_movedowntop all move/mesh/gran linear 0. 0. -${vc} units box topwall 1
label movedown
run 100
variable F equal f_topwall[3]
if '$F>999.99' then "jump banlance"
variable F delete
jump movedown