LIGGGHTS® - User Forum

Hello everyone,
I'm having problems finalizing my LIGGGHTS installation. I followed the installation tutorial and completed the make step. When it came time to testing the examples, it appears to run, but at the end it returns an error saying it cannot open dump file. Any ideas? Am I having a permissions problem? I've already tested that I can write to the folder.
Thanks in advance!
Carlos

p.s. Here is some sample output:

./LIGGGHTS < examples/LIGGGHTS/cohesion/in.cohesion
LIGGGHTS 1.1.7 based on lammps-10Mar10
Created orthogonal box = (-0.05 -0.05 0) to (0.05 0.05 0.15)

Hi LIGGGHTS users,
I used fix pour command and inserted particles with low number per insertion. Box is filled with 1/5th of the whole. Total number of particles is 30,000 with diameter 0.005m. However, when I filled the same system with other fix pour commands and increase the pouring number then it fills whole box. What is wrong with it?
Thank you in advance for help...
Ram

Is it possible to contrain the rotational degrees of freedom for granular particles?

Christian

Hi,

I am trying to get a text file containing the time history of quantities related to a single ball (eg force, coordinates,velocity).
What is the best way of doing this?
For resultant force on the ball and ball coordinates I have used the following:

variable z equal z[1]
variable fz equal fz[1]
fix extra all print 1 "$z ${fz}" file Myfile.txt

Hi,
I am creating balls and my coordinate lists have sqrt(2), sqrt(3) etc in them. I was wondering: what is the precision of LIGGGHTS? ie How many digits of the ball coordinates is it meaningful for me to include? Or, what is the furthest decimal digit that can be represented?
Thanks,
George

Is there any manual for LIGGGHTS?
Thanks,

Ozgur Keles

Hi Everybody,

It's been a while since my last update of Liggghts because of labwork and holydays, but yeesterday I updated my LIGGGHTS from 1.03 to 1.16 and made minor changes in my simulation (adding a dump for wall-stress).

However my results now look totaly different than what they looked like in 1.03 (see videos: www.yrthy.de/1_16.avi and www.yrthy.de/1_03.avi). It seems that the particles lost their cohesion.

Hi everybody,

I'm running a simulation for the compressing a soft material between a static wall and a moving-mesh-wall. The wall is moving with a constant speed.

Is there a quick way to get the overall force with which the mass ist pushing against the wall?

regards,
Martin

The download page says "The download section is on the bottom of the page. You have to login in order to have access to the download section! If you do not have an account yet, please register for free.", but I am already logged in!

Ideas? I tried two different browsers (Chrome/Firefox).

Hi,

I have a simulation where my wall geometry is a variable (eg where I want to change the value for the angle between two flat bits of my wall mesh)
Is there any way I could do this? I tried putting this as a variable in my stl file but I do not think it worked

eg
facet normal sin(${thita}) 0.0 -cos(${thita})
outer loop
vertex 0.02 0.0 0.0
vertex 0.06 0.06 0.04*tan(${thita})
vertex 0.06 0.0 0.04*tan(${thita})
endloop
endfacet