So you want
1. -granular particles
2. -a wall with a hole in it an
3. -constant stress on the wall
For 2, do what Steve says. However, before you do that, you should
figure out how to do 1 and 3, without a hole. fix box/relax is only
for minimization, it does not do dynamics.
Aidan
Firstly thank you for the very useful inputs.
I think I have figured a way out of modifying the fix wall/gran file by
deleting the particles lying very close to the desired patch.
I am confused by your comment on fix box/relax. I understand that it is only
for minimization and would not be applicable to the rotational energy stored
in the granular particles. I was hence thinking of using booth the commands
fix box/relax and fix nve/sphere in order to have the boundary conditions in
place as well as the desired Newtonian motions I want from the grains in
place. Do you think this would work?
If this does not work, is there any way to deform the box under a condition
of anisotropic stress on the granular sample especially when the box
boundaries are not periodic?
For deleting the particles from the specific patch I was thinking of using
the "run every" command along with "delete_atoms" from that patch volume
described as a region. Any comments on this?
Also does "run X every Y" allow executing more than one command every Y
steps uptil X steps?
Thank you very much
Ripudaman
I am confused by your comment on fix box/relax. I understand that it is only
for minimization and would not be applicable to the rotational energy stored
in the granular particles. I was hence thinking of using booth the commands
fix box/relax and fix nve/sphere in order to have the boundary conditions in
place as well as the desired Newtonian motions I want from the grains in
place. Do you think this would work?
No - you can't use fix box/relax during dynamics nor fix nve/sphere during
minimization.
If this does not work, is there any way to deform the box under a condition
of anisotropic stress on the granular sample especially when the box
boundaries are not periodic?
What does it mean to deform a sample that is not periodic? What
is providing the stress?
For deleting the particles from the specific patch I was thinking of using
the "run every" command along with "delete_atoms" from that patch volume
described as a region. Any comments on this?Also does "run X every Y" allow executing more than one command every Y
steps uptil X steps?
No - but you can always loop over a run followed by many commands, using
the next and jump commands.
Steve
Hi,
I need to change the radius of the particles with time. In effect I need to
grow the granular particles to a particular size or condition while
following hertzian contact mechanics. How can I do this?
Thank you
Ripudaman
The set diameter command could be used in a loop
to change particle sizes incrementally (followed by a run).
If you want to change them more continuously, during
one long run, then you'd need to write a fix to do that.
Steve
Hi LAMMPS users,
I am trying to compile LAMMPS with MPICH 1.2.7 which I installed on my
system myself. I am unable to locate the libmpi.a library file to create the
right Makefile. In the mpich/lib directory, there are a bunch of lib*.a
files. But there is no file that is libmpi.a. I tried finding the file from
root using find but I am unable to locate it. The files I found in the lib
directory are :-
libampe.a
Libfmpich.a
Liblmpe.a
Libmpe.a
Libmpe_nompi.a
Libmpich.a
Libmpichfsup.a
Libpmpich.a
Libpmpich++.a
Libtmpe.a
Mpe_prof.a
Kindly help me out in this. By the way my system is Red Hat 4 pack 6.
Thank you
Ripudaman Manchanda
Geomechanics Intern
Schlumberger DCS
1325 S. Dairy Ashford
Houston, TX 77077
Phone:
+1 281 285 1311 (office)
+1 512 751 8501 (cell)
Hi LAMMPS users,
I am trying to compile LAMMPS with MPICH 1.2.7 which I installed on my
system myself. I am unable to locate the libmpi.a library file to create the
right Makefile. In the mpich/lib directory, there are a bunch of lib*.a
files. But there is no file that is libmpi.a. I tried finding the file from
there is no libmpi.a, because the corresponding file for MPICH is called
libmpich.a. in general, it is not recommended to link with the MPI
runtime libraries directly, but rather use the mpi compiler wrappers
(mpiCC, mpicxx, or mpic++) for that. they are supposed to add them
automatically. unfortunately the wrappers for some MPI implementations
(and particularly MPICH) are so broken that people avoid using them
in their makefiles and list the MPI libraries and flags explicitly.
cheers,
axel.