Hi all Lammps users,
I am working with 2D granular simulation and going to do shear stress calculations. I have two questions related to the deformation and the relaxation the simulation box.
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The first question is, can I use the minimize command to relax the system since I work with the frictional granular packings ? Because I already work with that command and it didn’t work. (I came to know that we cannot use the minimize command with the frictional system)
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If I cannot work with minimize command for relax the system after I sheared it, the other way to relax the system is just running the system during large number of timesteps… That made a problem with the fix_deform command which I used for the deform the system. First I would leave the fix deform command here,
"fix 2 all deform 1 xy erate ${mystrainrate} remap x"
This will deform the box with a constant shearing rate of ${mystrainrate} after every single timestep, proportional to the elapsed time of the system… Then I will have to relax the system by performing lange number of timesteps… This is where I got the problem. During the box relaxation time, box continues to deform as well… I want to turn off the above fix command during the system relaxation. Then again I want to turn it on. I read some stuffs regarding this, but I couldn’t figure out how to solve this problem.
Could you please anyone help me ?
Thank you so much.
Nira.
Hi all Lammps users,
I am working with 2D granular simulation and going to do shear stress
calculations. I have two questions related to the deformation and the
relaxation the simulation box.
1) The first question is, can I use the minimize command to relax the system
since I work with the *frictional* granular packings ? Because I already
work with that command and it didn't work. (I came to know that we cannot
use the minimize command with the frictional system)
2) If I cannot work with minimize command for relax the system after I
sheared it, the other way to relax the system is just running the system
during large number of timesteps... That made a problem with the fix_deform
command which I used for the deform the system. First I would leave the fix
deform command here,
"fix 2 all deform 1 xy erate ${mystrainrate} remap x"
This will deform the box with a constant shearing rate of ${mystrainrate}
after every single timestep, proportional to the elapsed time of the
system... Then I will have to relax the system by performing lange number of
timesteps... This is where I got the problem. During the box relaxation
time, box continues to deform as well... I want to turn off the above fix
command during the system relaxation. Then again I want to turn it on. I
read some stuffs regarding this, but I couldn't figure out how to solve
this problem.
Could you please anyone help me ?
how about using "change_box" instead of fix deform?