shear test

Submitted by prasantud on Tue, 09/13/2011 - 12:21

Hi everybody,
I would like to start the shear test using LIGGGHTS.
Could you help me in doing it.
I was using velocity command for the control of temperature. So far no success. I came to know about the shear test from the following message.
Many thanks in advance.
Samantaray

Tue, 11/30/2010 - 17:18 — tshan

Dear all,

I have already done some triaxial tests and simple shear tests, but I want to know the contact normal among the particles and then realise them in paraview to further generate the force-chain.

Is there someone who has done the force-chain stuff before? Could you tell me how to do this or give me some hints?

Thanks in advance!

Best,
Tong

Forums:

prasantud | Tue, 09/13/2011 - 12:30

Hi Chris,
I am modifying the shear LAMMPS example to atom_style granular in LIGGGHTS.
I dont know the reason following codes for the temperature control and onwards.
1. Why the first velocity command is used...
2. why to fix nve for the non-equilibrium case
Kind regards,
Samantaray

# temp controllers
velocity mobile create 300.0 5812775 temp new3d
fix 1 all nve
fix 2 boundary setforce 0.0 0.0 0.0

fix 3 mobile temp/rescale 10 300.0 300.0 10.0 1.0
fix_modify 3 temp new3d

thermo 25
thermo_modify temp new3d
timestep 0.000001
run 1000

ckloss's picture

ckloss | Wed, 09/14/2011 - 16:55

Hi,

have a look at the compression and compression_triaxial example as a start
The "shear" example is probably not very good to start with - it is MD, not DEM - temperature control does not make sense for granular shear cell.

Christoph

adabubu | Thu, 09/22/2011 - 16:11

Hi, I have simulated a shear test (simple shear test). but it didn't like the example in LAMMPS. What I focus on is how to define the constant confining pressure in LGGGHTS. If you like, I can send you my example, maybe it will help you. My email is xuetao.wang@zueblin.de

ckloss's picture

ckloss | Thu, 09/22/2011 - 16:27

Hi xuetao,

the "shear" example in LAMMPS is for molecular shear flow, and therefore has not much to do with a shear cell...
There are some other people working on shear cell simulation in LIGGGHTS - maybe you can connect?
e.g. user: Yansan
It would be great if you could share your results - just open a new forum thread, then you can attach it there

Cheers, Christoph

prasantud | Fri, 09/23/2011 - 09:54

Hi Wang,
Please send me the shear test example. We can discuss on including it in LIGGGHTS if possible.
Thanking you,
Samantaray