24小时热门版块排行榜

返回列表

当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

莽子大虾

金虫 (小有名气)

应助: 1 (幼儿园)
金币: 817.5
红花: 1
帖子: 62
在线: 23.5小时
虫号: 3163468
注册: 2014-04-25
专业: 金属材料的力学行为

[交流] 用velocity拉伸的时候感觉参数不受控制啊？已有5人参与

小弟测试velocity拉伸的时候在拉伸方向无论多少的速度值都没用啊？哪位大神能帮我看看哪里有错误啊？碳纳米管长60埃，左侧z方向的坐标为0，右侧z方向的坐标为60，下面是我的in文件：
# ------------------------ INITIALIZATION ----------------------------
dimension       3
units          metal
boundary       s s s
atom_style       atomic

# ----------------------- ATOM DEFINITION ----------------------------
lattice          sc 1
region          1 cylinder z 0.0 0.0  8  -5 65 units box
read_data       data.CNT

# ------------------------ FORCE FIELDS ------------------------------
pair_style       airebo 6.8 1 0
pair_coeff       * * CH.airebo  C

# ------------------------- SETTINGS ---------------------------------
group          innertube region 1
region          2 cylinder z 0.0 0.0  8  -5 2 units box
group          left region 2
region          3 cylinder z 0.0 0.0  8  58 65 units box
group          right region 3
#group          right subtract innertube left
variable zinner  equal xcm(innertube,z)
variable minner  equal xcm(innertube,z)
compute          s innertube stress/atom NULL
compute          peratom all pe/atom

######################################
# EQUILIBRATION
reset_timestep    0
timestep       0.001

min_style       sd
minimize       1.0e-12 1.0e-12 1000 1000

velocity innertube create 300.0 4928459 rot yes dist gaussian
fix 1 all nvt temp 300 300 0.1

# Set thermo output
thermo 1000
thermo_style custom step lx ly lz press pxx pyy pzz pe temp v_minner
run 10000
unfix 1

# Store final cell length for strain calculations
variable tmp equal "lz"
variable L0 equal ${tmp}
print "Initial Length, L0: ${L0}"

######################################
# DEFORMATION
reset_timestep 0

fix 2 all nvt temp 300 300 0.1
#variable srate equal 1.0e10
#variable srate1 equal "v_srate / 1.0e12"
#fix 3 innertube deform 1 z erate ${srate1} units box remap x
velocity       innertube set  0.0 0.0 0.0 units box
fix          3 innertube setforce 0.0 0.0 0.0
velocity       left set NULL NULL -0.001 sum yes units box
velocity       right set NULL NULL 0.001 sum yes units box

# Output strain and stress info to file
# for units metal, pressure is in [bars] = 100 [kPa] = 1/10000 [GPa]
# p2, p3, p4 are in GPa
variable strain equal "(lz - v_L0)/v_L0"
variable p1 equal "v_strain"
variable p2 equal "-pxx/10000"
variable p3 equal "-pyy/10000"
variable p4 equal "-pzz/10000"
fix def1 all print 100 "${p1} ${p2} ${p3} ${p4}" file Al_SC_100.def1.txt screen no

dump 1 all custom 1000 CNT.lammpstrj id type x y z fx fy fz
# Display thermo
thermo 1000
thermo_style custom step v_strain temp v_p2 v_p3 v_p4 ke pe press lz v_minner

run 20000
######################################
# SIMULATION DONE
print "All done"
输出的信息为：
Step strain Temp p2 p3 p4 KinEng PotEng Press Lz minner
   0 0.0037365905 3.8565238e-011  -0.42502796  -0.61388038 0.37445622 4.4814685e-012 -6865.2825 2214.8404 59.593997    29.99946
1000 0.0037365905 1.2198606e-008  -0.42500594  -0.61386409 0.37604147 1.4175375e-009 -6865.2821 2209.4285 59.593997    29.99946
2000 0.0037365905 2.4239662e-005  -0.42420524 -0.6132768 0.43592395 2.8167667e-006 -6865.267 2005.1936 59.593997    29.99946
3000 0.0037365905 0.10980239  -0.47745829  -0.67042215 3.2323895  0.012759572 -6856.8251 -6948.3635 59.593997    29.99946
4000 0.30985771 384.56638  -0.65840803  -0.77243865 0.06564382 44.688486 -6691.5308 4550.6762 77.769065    29.99946
5000 1.2320854 319.90647  -0.38637448  -0.45329122 0.15036334    37.17469 -6691.5308 2297.6746    132.5237    29.99946
6000 2.1906111 272.98051  -0.27029958  -0.31711315 0.16197403 31.721665 -6691.5308    1418.129 189.43343    29.99946
7000 3.1133352 286.53103  -0.20966461  -0.24597672 0.11292056 33.296301 -6691.5308 1142.4026 244.21755    29.99946
8000 4.0690343 320.44628  -0.17013514  -0.19960108  0.065799461 37.237418 -6691.5308 1013.1225 300.95945    29.99946
9000 4.9895184 309.95901  -0.14398835  -0.16892589  0.062447271 36.018747 -6691.5308 834.88989 355.61057    29.99946
10000 5.9472747 283.54833  -0.12413801  -0.14563764  0.068515467 32.949697 -6691.5308 670.86728 412.47462    29.99946
11000 6.8644522 291.22497  -0.10966064  -0.12865292  0.056756361    33.84176 -6691.5308 605.19065 466.92942    29.99946
12000 7.8198568 314.71927 -0.097781728  -0.11471668  0.040323854 36.571912 -6691.5308 573.91519 523.65384    29.99946
13000    8.740685 307.35174 -0.088538008  -0.10387203  0.039432058    35.71577 -6691.5308    509.9266 578.32539    29.99946
14000 9.6970053    287.0275 -0.080622643 -0.094585793  0.043242322 33.353993 -6691.5308 439.88705 635.10418    29.99946
15000 10.620286 293.17787 -0.074216834 -0.087070553  0.037763092 34.068696 -6691.5308 411.74765 689.92134    29.99946
16000 11.579521 312.15349 -0.068557526 -0.0804311 0.02905966 36.273756 -6691.5308 399.76322 746.87318    29.99946
17000 12.503847 305.95911 -0.063864825 -0.074925664  0.028841556 35.553938 -6691.5308 366.49644 801.75241    29.99946
18000    13.46276    288.895 -0.059630449  -0.06995793  0.031484535 33.571006 -6691.5308 327.01281 858.68509    29.99946
19000 14.386393 294.34889 -0.056050877 -0.065758407  0.028226033 34.204774 -6691.5308 311.94417 913.52322    29.99946
20000 15.344039 310.63194  -0.05276669 -0.061905427 0.02272578 36.096944 -6691.5308 306.48779 970.38071    29.99946
为什么应变的增量会这么大？感觉完全不受控制，改velocity z方向的值也没用？不知道我的in文件那个地方用错了，还请各位大神帮帮忙修改一下。

回复此楼