Impact of two rigid bodies - Fracture

Submitted by zealakis on Wed, 08/24/2016 - 06:01

hello,

I've been working with liggghts for a while. I have simulated the impact of two rigid bodies and now I would like to analyze the movement of the particles that form the body as if one of them could break . Something similar to what happens in this video ( shown in LIGGGHTS -PUBLIC FEATURES section):

http://www.cfdem.com/media/DEM/nonspherical/lammps_granular+multibody_.wmv

As we can see , a rigid body impacts a plate of particles. I could'nt find the scrip that simulates this behavior. I'd be very gratefull if someone can help me because i need taht to resolve what I have in mind.

Also, It would be helpful if i had the files of this example:

http://www.cfdem.com/media/DEM/stress/stress.avi

Thanks a lot and have a nice day,
zealakis

Forums:

ckloss's picture

ckloss | Tue, 09/13/2016 - 15:20

Hi zealakis,

you're lucky that we just released a feature which does (at least to some extent) what you want: Have a look at fix multisphere/break!
(disclaimer: it's the initial release so it's a bit experimental)

Best wishes
Christoph

duanzheng83 | Thu, 02/16/2017 - 16:41

Hi Christoph

In the "multisphere_stone_restitution" example, I add

"fix m6 all property/atom fz scalar yes no no 0.02"
before integrator, and change integrator to be

"fix integr all multisphere/break trigger_threshold 0.1 trigger_timeStep 0 trigger_fixName m6"

After type ./lmp_fedora -echo both < in.multisphere, I get the ERROR of

run 20000 upto
ERROR: Could not locate a fix/property storing value(s) for m6 as requested by multisphere/break. (../modify_liggghts.cpp:385)
(../modify_liggghts.cpp:385)

Could you give some hint on how to figure it out?

ckloss's picture

ckloss | Mon, 02/27/2017 - 20:54

Hi,

the trigger name should be "fz" since this is the variable name. 

Best wishes

Chris