Dear lammps user
Hello
I want to simulate nanoindentation on monolaer graphene.
But I can find some problem that the graphene sheet is not stable at al.
I cannot fix this problem. I appriciate if you can help me solving this problem.
Here below is my scripts.
Thanks in advanced.
---------------------------- INITIALLIZE --------------------------------
units metal
dimension 3
boundary s s s
atom_style atomic
--------------------------- ATOM DEFINITION -----------------------------
#—GRAPHENE
lattice custom 2.4595 &
a1 1 0 0 &
a2 0 1.732050807569 0 &
basis 0 0 0 &
basis 0.5 0.16666666667 0 &
basis 0.5 0.5 0 &
basis 0.0 0.66666666667 0
region simulationbox block 0 200 0 200 -20 26 units box
create_box 2 simulationbox
region graphene block 0 200 0 200 0 1 units box
create_atoms 1 region graphene
group monolayer region graphene
#fix 9 monolayer setforce 0.0 0.0 0.0 region graphene
velocity monolayer
region fixed cylinder z 100 100 90 -20.0 30.0 side out units box
group fixedgr region fixed
fix 2 fixedgr rigid/nvt group 1 fixedgr temp 300.0 300.0 0.01
#—INDENTER
lattice diamond 3.57
region indenter sphere 100.0 100.0 26.0 16.0 units box
create_atoms 2 region indenter
group indent region indenter
fix 4 indent rigid/nvt group 1 indent temp 300.0 300.0 0.01
mass 1 12.01
mass 2 12.01
velocity all create 300.0 100000
----------------------------- FORCE FIELD -------------------------------
pair_style hybrid tersoff lj/cut 0.1
pair_coeff * * tersoff SiC.tersoff C C
pair_coeff 1 2 lj/cut 2.964 3.407
neighbor 2.0 nsq
neigh_modify every 10 check yes
----------------------------- INDENTATION -------------------------------
#velocity all create 300.0 100000
#timestep 0.005
thermo 100
thermo_style custom step temp ke pe etotal
thermo_modify norm no
fix 3 all nvt temp 300.0 300.0 1.0
fix 5 indent move wiggle 0.0 0.0 -5.0 500.0 units box
fix 3 all nvt temp 300.0 300.0 1.0
dump graphene all atom 100 gra_indent_ja8.dump
run_style verlet
run 160000
unfix 5