Dear all,
I am simulating the contact of a rigid cylinder with deformable block. I am not integrating the cilinder, but just moving the block with constant v. I have a reservoir in the under the block and both solids in study are in nve. Since normal force is very important in contact mechanics, I have to calculate it. So, I got the fy for every atom and I am summing only the y coordinate of the indentator. Is it ok like that, even if the rigid cylinder is not being integrated? I am getting a little big values.
Another question is what is the best way to calculate the von mieses stress in such a sistem. Is there any effect in the thermodinamics I should consider when simulating the block with constant velocity, since I am using thermo_modify and compute temp/com for the block temperature?
Thanks a lot!
Débora Marques
These are the scripts:
For the Contact Simulation:
dimension 3
boundary p s p
atom_style atomic
neighbor 0.3 bin
neigh_modify delay 2 check no
units lj
create geometry
lattice fcc 1.0
read_restart restart.anneal.50000
velocidades iniciais
compute temperatura all temp
compute t1 hi temp/com
compute t2 lo-fixed temp/com
compute t3 lo temp/com
compute 1 lo com
compute 2 lo-fixed com
compute 3 hi com
compute 4 lower-group centro/atom fcc
compute 5 lo msd com yes
compute 6 hi msd com yes
#displace
displace_atoms idn move 0 -4.3 0 units box
#fix
#unfix 3
fix 2 lo nve
fix 3b lo-fixed nvt temp 0.0623 0.0623 0.074
fix_modify 3b temp t2
velocity lower-group set NULL 0.791862285 NULL
velocity idn set 0.0000000 0.000000 0.0000000
#run main
thermo 500
thermo_style custom step temp ke pe etotal c_t1 c_t2 c_t3 etotal c_1[1] c_1[2] c_1[3] c_2[1] c_2[2] c_2[3] c_3[1] c_3[2] c_3[3] c_5[1] c_5[2] c_5[3] c_6[1] c_6[2] c_6[3]
timestep 0.0000148
dump 1a all atom 1000 dump.mat3-cut00_a
#dump 2 all atom 1000 dump.mat3-cut00b.*
dump 3 all xyz 10000 dump.mat3-cut00_c..xyz
dump 4 all custom 10000 dump.mat3-cut00_d. id type x y z vx vy vz fx fy fz c_4
write_restart restart.mat3-cut00.100000
run 1000000
write_restart restart.mat3-cut00.200000
run 1000000
write_restart restart.mat3-cut00.300000
run 100000
write_restart restart.mat3-cut00.400000
run 100000
For the anneal:
dimension 3
boundary p s p
atom_style atomic
neighbor 0.3 bin
neigh_modify delay 2 check no
units lj
create geometry
lattice fcc 1.0
region box block 0 50 0 80 0 9
create_box 3 box
mass 1 1.0
mass 2 1.0
mass 3 1.0
atom regions
region lo-fixed block INF INF 1.1 3.1 INF INF
region lo-slab block INF INF 3.2 11 INF INF
region b1 block INF INF 14.000 24.0900 INF INF
region cilindro cylinder z 25.000 25.000 10.0000 INF INF
region cyl intersect 2 b1 cilindro
create 2 surfaces with asperity
create_atoms 1 region lo-slab
create_atoms 2 region lo-fixed
create_atoms 3 region cyl
LJ potentials
pair_style lj/cut 2.2
pair_coeff * * 1.0 1.0 2.2
define groups
group lo region lo-slab
14400 atoms in group lo
group lo type 1
group idn region cyl
group hi type 2
group lo-fixed region lo-fixed
group lower-group union lo-fixed lo
set group lo-fixed type 3
initial velocity and compute
compute temperatura all temp
compute t1 hi temp
compute t2 lo-fixed temp
compute t3 lo temp
compute 1 lo com
compute 2 lo-fixed com
compute 3 hi com
#compute 4 lo centro/atom fcc
velocity all create 0.0623 482748 temp temperatura
#deslocando o upper-group
displace_atoms idn move 0 30.0 0 units box
#Fixes
#fix 3a lo nve
fix 3 lo nvt temp 0.0623 0.0623 0.001
#configurações do run
thermo 100
thermo_style custom step temp etotal c_t1 c_t2 c_t3 c_1[1] c_1[2] c_1[3] c_2[1] c_2[2] c_2[3] c_3[1] c_3[2] c_3[3]
timestep 0.0003#0.0148
run_style verlet
#run
dump 1 all atom 100 dump.010_anneal
dump 1b all xyz 100 dump.010_anneal..xyz
dump 1c all custom 100 dump.010_c. id type x y z vx vy vz fx fy fz
run 50000
