LAMMPS (10 Jan 2012) # 2d friction simulation dimension 2 boundary p s p atom_style atomic neighbor 0.3 bin neigh_modify delay 5 # create geometry lattice hex 0.9 Lattice spacing in x,y,z = 1.1327 1.96189 1.1327 region box block 0 50 0 22 -0.25 0.25 create_box 4 box Created orthogonal box = (0 0 -0.283174) to (56.6348 43.1615 0.283174) 1 by 1 by 1 MPI processor grid mass 1 1.0 mass 2 1.0 mass 3 1.0 mass 4 1.0 # atom regions region lo-fixed block INF INF INF 1.1 INF INF region lo-slab block INF INF INF 7 INF INF region above-lo block INF INF INF 7 INF INF side out region hi-fixed block INF INF 20.9 INF INF INF region hi-slab block INF INF 15 INF INF INF region below-hi block INF INF 15 INF INF INF side out region lo-asperity sphere 32 7 0 8 region hi-asperity sphere 18 15 0 8 region lo-half-sphere intersect 2 lo-asperity above-lo region hi-half-sphere intersect 2 hi-asperity below-hi # create 2 surfaces with asperities create_atoms 1 region lo-slab Created 750 atoms create_atoms 1 region hi-slab Created 750 atoms create_atoms 2 region lo-half-sphere Created 112 atoms create_atoms 3 region hi-half-sphere Created 112 atoms # LJ potentials pair_style lj/cut 2.5 pair_coeff * * 1.0 1.0 2.5 # define groups group lo region lo-slab 750 atoms in group lo group lo type 2 862 atoms in group lo group hi region hi-slab 750 atoms in group hi group hi type 3 862 atoms in group hi group lo-fixed region lo-fixed 150 atoms in group lo-fixed group hi-fixed region hi-fixed 150 atoms in group hi-fixed group boundary union lo-fixed hi-fixed 300 atoms in group boundary group mobile subtract all boundary 1424 atoms in group mobile set group lo-fixed type 4 150 settings made for type set group hi-fixed type 4 150 settings made for type # initial velocities compute new mobile temp/partial 0 1 0 velocity mobile create 0.1 482748 temp new velocity hi set 1.0 0.0 0.0 sum yes # fixes fix 1 all nve fix 2 boundary setforce 0.0 0.0 0.0 fix 3 mobile temp/rescale 200 0.1 0.1 0.02 1.0 fix_modify 3 temp new # Run timestep 0.0025 thermo 1000 thermo_modify temp new WARNING: Temperature for thermo pressure is not for group all (thermo.cpp:442) dump 1 all atom 500 dump.friction run 20000 Memory usage per processor = 2.05873 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 0.1 -3.1333672 0 -3.0921259 -1.1440102 2444.4558 1000 0.1 -3.0915465 0 -3.0503052 0.010017516 2444.4558 2000 0.1 -3.0826487 0 -3.0414074 -0.42021097 2444.4558 3000 0.089819692 -3.07584 0 -3.0387972 -0.25257042 2444.4558 4000 0.098489874 -3.0667093 0 -3.0260907 -0.25511521 2444.4558 5000 0.11379986 -3.0557087 0 -3.0087762 -0.080886978 2444.4558 6000 0.11269179 -3.04532 0 -2.9988445 -0.33387724 2444.4558 7000 0.1 -3.0380598 0 -2.9968185 -0.32430244 2444.4558 8000 0.1 -3.0346458 0 -2.9934045 -0.38022997 2444.4558 9000 0.1 -3.0323928 0 -2.9911515 -0.42944097 2444.4558 10000 0.1 -3.0354969 0 -2.9942556 -0.3547036 2444.4558 11000 0.11248007 -3.0371526 0 -2.9907643 -0.42222237 2444.4558 12000 0.10241295 -3.0422315 0 -2.9999951 -0.24193736 2444.4558 13000 0.11139984 -3.044969 0 -2.9990263 -0.32692165 2444.4558 14000 0.099297055 -3.0415792 0 -3.0006278 -0.34441013 2444.4558 15000 0.11494243 -3.045278 0 -2.9978742 -0.26868839 2444.4558 16000 0.11211716 -3.0460201 0 -2.9997815 -0.27620024 2444.4558 17000 0.11246574 -3.0461857 0 -2.9998034 -0.31782055 2444.4558 18000 0.11194476 -3.0440786 0 -2.9979112 -0.35902467 2444.4558 19000 0.11200621 -3.0473992 0 -3.0012064 -0.25540459 2444.4558 20000 0.10818968 -3.0456459 0 -3.0010271 -0.29452342 2444.4558 Loop time of 5.76747 on 1 procs for 20000 steps with 1724 atoms Pair time (%) = 4.63048 (80.2861) Neigh time (%) = 0.297429 (5.15701) Comm time (%) = 0.0432248 (0.749459) Outpt time (%) = 0.0548413 (0.950872) Other time (%) = 0.741497 (12.8565) Nlocal: 1724 ave 1724 max 1724 min Histogram: 1 0 0 0 0 0 0 0 0 0 Nghost: 145 ave 145 max 145 min Histogram: 1 0 0 0 0 0 0 0 0 0 Neighs: 14369 ave 14369 max 14369 min Histogram: 1 0 0 0 0 0 0 0 0 0 Total # of neighbors = 14369 Ave neighs/atom = 8.33469 Neighbor list builds = 717 Dangerous builds = 0