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标题: 求助：拉伸时如何消除内应力 [打印本页]

作者
Author: sj12138 时间: 2023-12-28 23:32
标题: 求助：拉伸时如何消除内应力
本帖最后由 sj12138 于 2024-1-10 16:52 编辑

各位老师好，我发现我拉伸之后的应力应变曲线不是从0开始的，查阅了一些资料，说要在npt弛豫时将拉伸方向的压力设为0，修改后还是不行，下面附上我的in文件，请教各位应该怎么解决？

#minimize
min_style    sd
minimize       1.0e-20 1.0e-20 100000 100000
fix mom  all  momentum 10 linear 1 1 1 angular
fix    1 all box/relax iso 0.0
velocity       all  create  270 $R mom yes rot yes dist gaussian
velocity       all  scale 270
run 0
unfix 1
fix    shake       all    shake    0.0001 20 0 b 1 a 1

#NVT
thermo_style custom time atoms step temp press vol lx ly lz enthalpy pe ke etotal density pxx pyy pzz pxy pxz pyz
thermo    ${thermo}
fix       NVT all  nvt  temp 270 270 100
dump       1 all  xyz  ${thermo}  nvt_${name}.xyz
dump_modify  1 element O  H  C
fix  vt all print 200 "${istep} ${T0} ${V}" screen no file nvt_${name}.dat
run       ${runnvt}
unfix          NVT
unfix          vt
undump          1
reset_timestep 0

#npt弛豫
fix       NPT all  npt  temp 270 270 100 x 98 98 1000 y 98 98 1000 z 0 0 1000
thermo_style custom time atoms step temp press vol lx ly lz enthalpy pe ke etotal density pxx pyy pzz pxy pxz pyz
thermo    ${thermo}
dump       1 all  xyz  ${thermo}  npt_${name}.xyz
dump_modify  1 element O  H  C
fix  pt all print 200  "${istep} ${etol} ${han} ${T0} ${V} ${PE} ${P0}" screen no file npt_${name}.dat
run       ${runmd}
undump          1
unfix          pt
unfix          NPT
reset_timestep 0

#stress-strain
variable tmpx equal "lx"
variable tmpy equal "ly"
variable tmpz equal "lz"

variable Lx0 equal ${tmpx}
variable Ly0 equal ${tmpy}
variable Lz0 equal ${tmpz}

variable strainx equal "(lx - v_Lx0)/v_Lx0"
variable strainy equal "(ly - v_Ly0)/v_Ly0"
variable strainz equal "(lz - v_Lz0)/v_Lz0"

variable stressx equal "-pxx/10000"
variable stressy equal "-pyy/10000"
variable stressz equal "-pzz/10000"

#z向拉伸
fix 2 all npt  temp 270 270 100 x 98 98 1000 y 98 98 1000
fix 3 all deform  100  z  erate  0.00000001  remap  x  units  box
thermo_style custom time atoms step temp press vol lx ly lz density pxx pyy pzz pxy pxz pyz
thermo    ${thermo}
dump       1 all xyz  ${thermo}  tension_${name}.xyz
dump_modify  1 element O  H  C

#保存应力应变数据
fix  def3  all  print  100  "${strainx} ${stressx} ${strainy} ${stressy} ${strainz} ${stressz}" screen no file stress-strain_${name}.dat

run          ${runten}

作者
Author: meili 时间: 2024-9-9 20:42
请问解决了吗

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