Need help in LAMMPS. Nanometric cutting

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1

Please check my input script first.:

units metal

boundary f f s

atom_style atomic

pair_style morse 3.4

read_data toola_15724.txt

pair_coeff * * 0.3429 1.35588 2.626

pair_coeff 1 2*4 0.1 1.7 2.2

neighbor 2.0 bin

neigh_modify delay 5

neigh_modify exclude type 1 1

group tool type 1

group newtonian type 2
group thermostat type 3

group boundary type 4

group mobile subtract all boundary tool

fix 1 tool rigid single

compute new mobile temp

velocity mobile create 293 5812775 temp new

velocity tool set 5 0 0 sum yes units box

fix 2 mobile nve

fix 3 boundary setforce 0.0 0.0 0.0

fix 4 tool setforce 0.0 0.0 0.0

velocity thermostat scale 293.0

#fix 5 all enforce2d

thermo 500

thermo_style custom step temp epair pe ke etotal vol press

thermo_modify temp new

thermo_modify lost warn

compute_modify new extra 4

dump 1 all atom 500 dump.testcul5morse
dump_modify 1 scale no

dump 2 all custom 500 dump.forcecul15morsetag xsu ysu zsu ix iy iz
timestep 0.002

run 10000

Okay.The script is working just fine but the problem is that during the cutting( projected through VMD) only the middle part of the work-piece can be cut. The boundary layer remain static. The cutting tool simply by-passing the boundary layer. I need to remove these layers!
Please click the link below which shows the snapshots of the cutting process.
http://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic4_zps996a641a.png

http://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic3_zpsd0b8ff6d.png

http://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic2_zpsc52718d9.png

http://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic1_zps7e31c600.png

2

By "the boundary layer" you mean the group boundary? Maybe it is not
moving because it has been applied with fix setforce 0 and the fact
that no integrator is applied to it?

Ray

3

Please check my input script first.:

units metalboundary f f satom_style atomicpair_style morse 3.4read_data toola_15724.txtpair_coeff * * 0.3429 1.35588 2.626pair_coeff 1 2*4 0.1 1.7 2.2neighbor 2.0 binneigh_modify delay 5neigh_modify exclude type 1 1group tool type 1group newtonian type 2
group thermostat type 3group boundary type 4group mobile subtract all boundary toolfix 1 tool rigid singlecompute new mobile tempvelocity mobile create 293 5812775 temp newvelocity tool set 5 0 0 sum yes units boxfix 2 mobile nvefix 3 boundary setforce 0.0 0.0 0.0fix 4 tool setforce 0.0 0.0 0.0velocity thermostat scale 293.0#fix 5 all enforce2dthermo 500thermo_style custom step temp epair pe ke etotal vol pressthermo_modify temp newthermo_modify lost warncompute_modify new extra 4dump 1 all atom 500 dump.testcul5morse
dump_modify 1 scale nodump 2 all custom 500 dump.forcecul15morsetag xsu ysu zsu ix iy iz
timestep 0.002run 10000
Okay.The script is working just fine but the problem is that during the cutting( projected through VMD) only the middle part of the work-piece can be cut. The boundary layer remain static. The cutting tool simply by-passing the boundary layer. I need to remove these layers!
Please click the link below which shows the snapshots of the cutting process.
http://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic4_zps996a641a.pnghttp://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic3_zpsd0b8ff6d.pnghttp://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic2_zpsc52718d9.pnghttp://i877.photobucket.com/albums/ab335/Dinesh_Balakrishnan/pic1_zps7e31c600.png

4

I have replied to this exact same question several days ago.

Ray