Hi Zimmerman and Cao, thanks for the advice.
In fact I want to simulate uniaxial tension. I only want to set the
pbc in the uniaxial direction(z), keep x y directions free surface. I
am not sure if this is right. However, if I use boundary s s p, the
stress-strain curve does not start at zero, there's stress even at the
first time step. However, when I using period boundary condition on
all directions (p p p), the stress seems fine. I think s s p(or s s s)
is what I want.
The problem I am confused is
1. Which boundary condition should be used if simulating uniaxial
tension of nano wire? s s p?
If I simulate nano rod with limited length, should I use (s s s)? In
this case which is the best way to add stress or strain in LAMMPS?
2. How to perform effective energy minimization in LAMMPS before
simulating? only use minimize command?
Many thanks for any advice.
The following is part of the input script.
boundary p p p
#boundary s s p
# Atom definition
pair_coeff * * Cu_u3.eam
neighbor 3.0 bin
neigh_modify delay 5
# temp controllers
compute new3d all temp
velocity all create 0.1 5812775 temp new3d
minimize 1.0e-6 1.0e-8 1000 100000
fix 1 all npt 0.1 0.1 100 aniso NULL NULL NULL NULL NULL NULL 1000 drag 2.0
fix 2 all deform 1000 z erate 0.001 x volume y volume remap v
compute peratom all stress/atom
thermo_modify temp new3d
dump 1 all atom 200 dump01.cu010110
# Run a simulation
2008/9/17 Zimmerman, Jonathan A <[email protected]>: