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) 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:442) dump 1 all atom 500 dump.friction run 20000 Memory usage per processor = 2.06212 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 0.1 -3.1333672 0 -3.0921259 -1.1440102 2444.4558 1000 0.081958665 -3.0927273 0 -3.0589265 -0.021850399 2444.4558 2000 0.082641883 -3.0850764 0 -3.0509938 -0.44968978 2444.4558 3000 0.092293442 -3.0748001 0 -3.0367371 -0.25358115 2444.4558 4000 0.096012911 -3.0565129 0 -3.0169159 -0.027674947 2444.4558 5000 0.1 -3.0465555 0 -3.0053142 -0.09934336 2444.4558 6000 0.11642983 -3.0390782 0 -2.991061 -0.21038719 2444.4558 7000 0.11597773 -3.0331763 0 -2.9853456 -0.46354952 2444.4558 8000 0.11937909 -3.0305563 0 -2.9813228 -0.30779188 2444.4558 9000 0.11109992 -3.0274146 0 -2.9815956 -0.52451724 2444.4558 10000 0.11600378 -3.0164577 0 -2.9686163 -0.35721513 2444.4558 11000 0.11403444 -3.0138385 0 -2.9668092 -0.45128937 2444.4558 12000 0.11732466 -3.0220572 0 -2.973671 -0.26756468 2444.4558 13000 0.10909933 -3.0270216 0 -2.9820276 -0.39570586 2444.4558 14000 0.10530217 -3.0326565 0 -2.9892285 -0.1708647 2444.4558 15000 0.11252086 -3.0326775 0 -2.9862724 -0.41750799 2444.4558 16000 0.10635548 -3.0310857 0 -2.9872233 -0.27111401 2444.4558 17000 0.11718463 -3.036313 0 -2.9879845 -0.34485392 2444.4558 18000 0.11632659 -3.0376748 0 -2.9897002 -0.2781061 2444.4558 19000 0.11302219 -3.0324168 0 -2.985805 -0.35512798 2444.4558 20000 0.11916746 -3.0379931 0 -2.9888469 -0.30162295 2444.4558 Loop time of 1.9566 on 4 procs for 20000 steps with 1724 atoms Pair time (%) = 1.17991 (60.3041) Neigh time (%) = 0.0769351 (3.93207) Comm time (%) = 0.391056 (19.9865) Outpt time (%) = 0.0432984 (2.21293) Other time (%) = 0.265402 (13.5644) Nlocal: 431 ave 486 max 376 min Histogram: 1 0 0 1 0 0 1 0 0 1 Nghost: 95 ave 119 max 75 min Histogram: 1 0 1 0 0 1 0 0 0 1 Neighs: 3599 ave 4160 max 3136 min Histogram: 1 0 1 0 0 1 0 0 0 1 Total # of neighbors = 14396 Ave neighs/atom = 8.35035 Neighbor list builds = 708 Dangerous builds = 0