LAMMPS (18 Feb 2013) # 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) 2 by 2 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:436) #dump 1 all atom 500 dump.friction #dump 1 all image 500 image.*.jpg type type # zoom 1.6 adiam 1.5 #dump_modify 1 pad 5 run 20000 Memory usage per processor = 2.06744 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 0.1 -3.1333672 0 -3.0921259 -1.1437867 2444.9333 1000 0.081958665 -3.0927273 0 -3.0589265 -0.021846131 2444.9333 2000 0.082641883 -3.0850764 0 -3.0509938 -0.44960195 2444.9333 3000 0.092293442 -3.0748001 0 -3.0367371 -0.25353161 2444.9333 4000 0.096012911 -3.0565129 0 -3.0169159 -0.027669541 2444.9333 5000 0.1 -3.0465555 0 -3.0053142 -0.099323956 2444.9333 6000 0.11642983 -3.0390782 0 -2.991061 -0.21034609 2444.9333 7000 0.11597774 -3.0331763 0 -2.9853456 -0.46345898 2444.9333 8000 0.11937899 -3.0305561 0 -2.9813226 -0.30773083 2444.9333 9000 0.111108 -3.0274067 0 -2.9815843 -0.5243749 2444.9333 10000 0.11666452 -3.0170603 0 -2.9689463 -0.37436916 2444.9333 11000 0.11005147 -3.0140407 0 -2.9686541 -0.46293236 2444.9333 12000 0.11286668 -3.0174735 0 -2.9709258 -0.28406396 2444.9333 13000 0.11280782 -3.0238036 0 -2.9772802 -0.41208934 2444.9333 14000 0.1 -3.0332072 0 -2.9919659 -0.1785001 2444.9333 15000 0.1148413 -3.0339717 0 -2.9866096 -0.4418584 2444.9333 16000 0.11194137 -3.0322089 0 -2.9860428 -0.29354474 2444.9333 17000 0.10699902 -3.0395654 0 -2.9954376 -0.37176577 2444.9333 18000 0.11091428 -3.0400366 0 -2.9942941 -0.19329155 2444.9333 19000 0.1094118 -3.0432032 0 -2.9980803 -0.38516174 2444.9333 20000 0.11137857 -3.0442022 0 -2.9982683 -0.37419199 2444.9333 Loop time of 1.97972 on 4 procs for 20000 steps with 1724 atoms Pair time (%) = 1.18649 (59.9324) Neigh time (%) = 0.0773743 (3.90835) Comm time (%) = 0.432971 (21.8703) Outpt time (%) = 0.000461817 (0.0233274) Other time (%) = 0.282418 (14.2656) Nlocal: 431 ave 493 max 377 min Histogram: 1 0 1 0 0 1 0 0 0 1 Nghost: 96 ave 125 max 77 min Histogram: 1 1 0 0 1 0 0 0 0 1 Neighs: 3596 ave 4228 max 3139 min Histogram: 1 1 0 0 0 1 0 0 0 1 Total # of neighbors = 14384 Ave neighs/atom = 8.34339 Neighbor list builds = 700 Dangerous builds = 0