Hi everyone.
I am trying to simulate an indentation of a substrate by a spherical rigid indenter. Anytime I run this simulation, the indenter simply passes through the substrate without permanent deformation of the substrate. Also, I noticed that the velocity command doesn’t work with rigid bodies. My script is as follows:
units metal
dimension 3
boundary p p p
atom_style atomic
variable latparam equal 5.43
######## SIMULATION BOX
region simulationbox block 0 500 0 500 0 400 units box
create_box 2 simulationbox
mass 1 12.01
mass 2 28.0855
######## SUBSTRATE
lattice fcc ${latparam}
region Si block 0 500 0 500 0 350 units box
create_atoms 2 region Si units box
group substrate region Si
######## ZONING OF SUBSTRATE
region mobile block 0 500 0 500 10.86 350 units box
group upper region mobile
region thermobile block 0 500 0 500 5.43 350 units box
group middle region thermobile
group thermo subtract middle upper
group fixed subtract substrate middle
neighbor 2.0 bin
neigh_modify delay 0 every 1 check yes
######## INDENTER
lattice fcc 3.57
region diamond sphere 100 100 360 8 units box
create_atoms 1 region diamond units box
group indenter region diamond
fix 12 indenter rigid single
######## INTERATOMIC POTENTIAL
pair_style hybrid morse 9 tersoff tersoff
pair_coeff * * tersoff 1 SiC.tersoff C NULL
pair_coeff * * tersoff 2 Si.tersoff NULL Si
pair_coeff 1 2 morse 0.435 4.6875 1.9475 1.5
######## INITIALIZE TEMPERATURE
velocity middle create 200 4186532 dist uniform mom yes rot yes
velocity thermo create 200 4186532 dist uniform mom yes rot yes
fix 2 fixed setforce 0.0 0.0 0.0
fix 19 middle temp/rescale 1 200 200 0.5 1.0
fix 70 substrate nve
dump equitempsrecent all xyz 100 dump.equitempsrecent
run_style verlet
thermo_style custom step temp ke pe
thermo 200
reset_timestep 0
run 1000
####### VERTICAL INDENTATIION
fix 100 indenter addforce 0.0 0.0 -0.05
dump vertical200 all xyz 100 dump.vertical200
run_style verlet
reset_timestep 0
run 2500
unfix 100
unfix 70
Any assistance will be most appreciated.
Thanks
Chionye Okwuashi
MS student,
Department of Mechanical Engineering,
Parks College of Engineering, Aviation, and Technology,
Saint Louis University.