LIGGGHTS® - User Forum

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

Dear liggghts users,
When I am generating restart files using liggghts, I am not able to convert it from binary file to data file.
It is showing me "Restart file version does not match restart2data version". I checked with many versions but still end up in same error. Can anyone tell me how to convert liggghts restart file to data file.
Thanking you

Shantanu Maheshwari

Although liggghts runs perfectly well, just need some advice on how to optimise runs for speed (particularly for granular flows with many particles).
Best regs,
BrianW