a04f267b54
git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@10655 f3b2605a-c512-4ea7-a41b-209d697bcdaa
187 lines
5.9 KiB
Plaintext
187 lines
5.9 KiB
Plaintext
echo both
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units metal
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atom_style charge
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dielectric 1.
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variable type string "_charge"
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boundary s s f
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# read in CNT
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read_data cnt_9_0_100${type}.init
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lattice diamond 3.6 # NOTE ???
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pair_style airebo 3.0
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pair_coeff * * ./CH.airebo C
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mass * 12.01
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# PARAMETERS-----------------------------
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variable dt equal 0.0005
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variable L equal zhi-zlo
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variable zhi equal zhi
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variable zTip equal ${zhi}-2.0 # 2 4
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variable zFree equal zhi
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variable R equal 12.1/2
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variable xhiFE equal 5.0*$R
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variable xloFE equal -${xhiFE}
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variable yhiFE equal $R
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variable yloFE equal -${yhiFE}
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variable zloFE equal zlo+10 # create fixed ghosts
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variable zhiFE equal zhi+(zhi-${zloFE})/12*2
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variable Lfree equal zhi-${zloFE}
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variable nx equal 10 # 5
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variable nz equal 14 # 12
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print "Length $L [${zloFE}, ${zhiFE}] ${zTip}"
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#variable E equal 0.1 # bias 1.0
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variable Vb equal 0.1 # 0.1 #0.5 #0.0 # bias
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variable Vg equal 0.5 # 1.0 # 5.0 0.5 #50.0 # 0.5 # gate/modulation
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print "bias voltage ${Vb}, gate voltage ${Vg}"
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variable ng equal 20 # 80 # 10
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variable nb equal 2 # 3
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variable n equal 100000
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variable s equal 250
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# END -----------------------------------
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region TIP block INF INF INF INF ${zTip} INF units box
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group TIP region TIP
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#region FIXED block INF INF INF INF INF ${zLoFE} units box
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#group FIXED region FIXED
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#group FREE subtract all FIXED
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region feRegion block ${xloFE} ${xhiFE} ${yloFE} ${yhiFE} ${zloFE} ${zhiFE} units box
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group internal region feRegion
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group FIXED subtract all internal
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fix FIX FIXED setforce 0 0 0
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variable nAll equal count(all)
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variable nGhost equal count(all)-count(internal)
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variable nTip equal count(TIP)
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print ">>> number of stationary ghosts: ${nGhost} of ${nAll}"
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print ">>> number of tip atoms : ${nTip}"
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neighbor 5. bin
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neigh_modify every 10 delay 0 check no
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timestep ${dt}
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thermo 100
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variable tag string "electrostatic_bending"
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# set charge on tip
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variable C equal -0.025
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print "charge $C [e]"
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variable c equal $C/${nTip}
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set group TIP charge $c
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# coupling
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fix AtC internal atc electrostatic CNT_id.mat
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fix_modify AtC include atomic_charge
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fix_modify AtC internal_quadrature off
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# note weights don't affect phi or f
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fix_modify AtC atom_weight constant internal 1.0
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fix_modify AtC extrinsic short_range off
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#fix_modify AtC atom_element_map eulerian 1
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fix_modify AtC control momentum flux
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fix_modify AtC mesh create ${nx} 1 ${nz} feRegion f p f
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# initial conditions
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fix_modify AtC initial displacement x all 0.0
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fix_modify AtC initial displacement y all 0.0
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fix_modify AtC initial displacement z all 0.0
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fix_modify AtC initial velocity x all 0.0
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fix_modify AtC initial velocity y all 0.0
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fix_modify AtC initial velocity z all 0.0
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fix_modify AtC initial electric_potential all 0.0
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# node sets
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variable t equal 1.1*$R
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fix_modify AtC mesh create_nodeset tube -$t $t -$t $t ${zloFE} ${zFree} units box
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fix_modify AtC mesh create_nodeset lefttube -$t $t -$t $t ${zloFE} ${zloFE} units box
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fix_modify AtC mesh create_nodeset rbc INF INF INF INF ${zhiFE} ${zhiFE} units box
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fix_modify AtC mesh create_nodeset lbc INF INF INF INF ${zloFE} ${zloFE} units box
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fix_modify AtC mesh create_nodeset top ${xhiFE} ${xhiFE} INF INF INF INF units box
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fix_modify AtC mesh create_nodeset bot ${xloFE} ${xloFE} INF INF INF INF units box
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# boundary conditions
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fix_modify AtC fix displacement x lbc 0.
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fix_modify AtC fix displacement y lbc 0.
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fix_modify AtC fix displacement z lbc 0.
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fix_modify AtC fix velocity x lbc 0.
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fix_modify AtC fix velocity y lbc 0.
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fix_modify AtC fix velocity z lbc 0.
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# ground
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fix_modify AtC fix electric_potential lbc 0
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# bias
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fix_modify AtC fix electric_potential rbc ${Vb}
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# gate
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fix_modify AtC fix electric_potential bot ${Vg}
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# run
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compute CM TIP com
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compute q all property/atom q
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compute Q all reduce sum c_q
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compute FSUM all reduce sum fx fy fz
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compute RSUM internal reduce sum fx fy fz
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thermo_style custom step etotal ke c_CM[1] c_CM[2] c_CM[3] &
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c_Q f_AtC[4] f_AtC[5] f_AtC[6] f_AtC[7] f_FIX[1] f_FIX[2] f_FIX[3] f_AtC c_FSUM[1] c_RSUM[1]
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thermo $s
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fix_modify AtC output ${tag}FE 100000000 full_text # $s full_text #binary
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fix_modify AtC output index step
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# NOTE not recognized as vector by paraview
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variable uX atom x-f_AtC[1]
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variable uY atom y-f_AtC[2]
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variable uZ atom z-f_AtC[3]
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variable rho atom mass*f_AtC[4]
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dump CONFIG all custom $s ${tag}.dmp id type x y z v_uX v_uY v_uZ v_rho
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reset_timestep 0
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log ${tag}.log
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# [eV/A * A^2] --> [N m]
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variable eV2J equal 1.60217646e-19
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variable A2m equal 1.e-10
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thermo 10
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timestep 0.0
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min_modify line quadratic
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variable Vg equal 0.1
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variable Lx equal 1.0
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variable ng equal 4
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#compute RSUM FREE reduce sum fx fy fz
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#dump CONFIG all custom 10000 ${tag}.dmp id type x y z c_U[1] c_U[2] c_U[3] fx fy fz
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variable a equal 0
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variable i loop ${ng}
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label loop_i
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variable b equal ($i-1)*${Vg}/(${ng}-1)/${Lx}
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fix_modify AtC fix electric_potential all linear 0 0 0 $b 0 $a 0
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min_style cg
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min_modify line quadratic
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#minimize 0 0 100000 100000
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minimize 0 0 1000 1000
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min_style sd
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min_modify line backtrack
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#minimize 0 0 100000 100000
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minimize 0 0 1000 1000
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fix_modify AtC output now
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# u = F L^3 / 3 EI --> EI = F L^3 / 3 u
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variable u equal c_CM[1]
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variable uz equal c_CM[3]
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# variable F equal f_AtC[5]
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# variable Fz equal f_AtC[7]
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variable F equal c_RSUM[1]
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variable Fz equal c_RSUM[3]
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variable R equal $F-$C*$b
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variable Rz equal ${Fz}-$C*$a
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variable EI equal $F*${Lfree}*${Lfree}*${Lfree}/3./$u
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variable EI equal ${EI}*${eV2J}*${A2m}
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#print "flexural rigidity ${EI} [Nm^2] NOTE z force"
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print ">> V $b $a F $F ${Fz} u $u ${uz} c $c phi 0 EI ${EI} R $R ${Rz}"
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next i
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jump SELF loop_i
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