新人求问，为什么做非线性屈曲分析后结构无变形？

新人刚刚接触ANSYS，做特征值屈曲分析的时候感觉没问题，但是做非线性屈曲结构就基本没变形，求大家给指导下，命令如下：/filname,cylinder_hole,1
/com,structural
/units,si
/PREP7
ET,1,SHELL181
KEYOPT,1,1,0
KEYOPT,1,3,0
KEYOPT,1,8,2
KEYOPT,1,9,0
KEYOPT,1,10,0
!R,1,0.001
MPTEMP,1,0
MPDATA,EX,1,,1.4e10
MPDATA,EY,1,,1e10
MPDATA,EZ,1,,1.5e10
MPDATA,PRXY,1,,0.3
MPDATA,PRYZ,1,,0.32
MPDATA,PRXZ,1,,0.45
MPDATA,GXY,1,,8e9
MPDATA,GYZ,1,,7e9
MPDATA,GXZ,1,,9e9
sect,1,shell,,
secdata, 0.001,1,0.0,3
secdata, 0.001,1,0.0,3
secdata, 0.001,1,0.0,3
secdata, 0.001,1,0.0,3
secoffset,MID
CYL4, , ,0.25, , , ,2
VDELE, 1
FLST,2,2,5,ORDE,2
FITEM,2,1
FITEM,2,-2
ADELE,P51X
wpoff,0,0,1
wpro,,,90.000000
CYL4, , ,0.12, , , ,0.3
FLST,2,4,5,ORDE,2
FITEM,2,3
FITEM,2,-6
AOVLAP,P51X
VDELE, 1, , ,1
FLST,2,6,5,ORDE,2
FITEM,2,7
FITEM,2,-12
ADELE,P51X, , ,1
CSYS,0
WPAVE,0,0,0
wpro,,,-90
ESIZE,0.03,0
MSHAPE,0,2D
MSHKEY,0
FLST,5,2,5,ORDE,2
FITEM,5,13
FITEM,5,-14
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
allsel
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
SAVE
FINISH
/SOL
antype,0
PSTRES,on
lsel,s,line,,5,8,1
DL,all, ,ALL,
allsel
lsel,s,line,,1,4,1
SFL,all,PRES,1,
allsel
SOLVE
save
FINISH
/SOLU
ANTYPE,BUCKLE
BUCOPT,LANB,1,
allsel
SOLVE
FINISH
/SOLU
EXPASS,1
MXPAND,1,0,0,0,0.001,
allsel
SOLVE
save
FINISH
/post1
*get,pressure1,mode,1,freq
nsort,u,sum
*get,max_disp_sum,sort,,max
finish
/prep7
upgeom,0.005,1,1,'cylinder_hole','rst',''
finish
/solu
antype,0
nlgeom,1
nsubst,50,0,0
arclen,on,4,
outres,all,all
allsel
lsel,s,line,,1,4,1
SFL,all,PRES,pressure1,
solve
finish