Hi, Lammps users,
I have a question about the structure optimization under pressure.
My system contains three regions. As shown in the following plot, target region is in the middle of upper and lower region. I am trying to optimize the structures of target region under uniaxial compression while keeping the upper and lower region rigid. The compression is applied in the direction along which the boundary of the system is non-periodic.
Force
|/
------------------------------------- s
upper_region | /|
------------------------------------- |
target_region | |_____ p
------------------------------------- /
lower_region | /
------------------------------------- p
Here are the commands used for this optimization:
fix f1 lower setforce 0.0 0.0 0.0
fix f2 upper aveforce 0.0 0.0 0.0
fix pull upper addforce 0 0 -1500
fix_modify pull energy yes
Do these commands make sense? Thank you very much!