热屈曲中怎样得到荷载位移曲线

你歌

前几天发贴询问热屈曲问题，前两天自己苦思冥想总算解决了薄板的热屈曲临界温度，与解析值相吻合，喜忧参半，喜的是此法可通，忧的是有限元也是基于线弹性理论得出来的临界温度，是分支点失稳。我所关心的是极值点失稳，得到非线性屈曲强度，要得到载荷和位移的曲线，可这条曲线却得不出来。命令流如下：
/FILNAME,BUCKSHELL63111122222
/TITLE,QUQU
/PREP7
ET,1,SHELL181
R,1,0.002
MP,EX,1,2.1E11
MP,PRXY,1,0.3
MP,DENS,1,7800
MP,KXX,1,70
MP,ALPX,1,3E-6
mp,reft,1,0
RECTNG,0,0.25,0,0.35
LESIZE,ALL,0.01
AMESH,ALL
LSEL,ALL
NSLL,S,1
D,ALL,UX
D,ALL,UY
D,ALL,UZ
ALLSEL,ALL
BF,ALL,temp,1
finish

/solu
antype,0
PSTRES, ON
EQSLV,SPAR
SOLVE
FINISH


/SOLU
ANTYPE,1
BUCOPT,LANB,5,0,0   
MXPAND,5,0,0,1,0.001
SOLVE
FINISH


/CONFIG,NRES,100
/PREP7
UPGEOM,0.01,1,1,'BUCKSHELL63111122222','RST'
tb,biso,1,1,2
tbdata,,4e8,0,,,,
/SOLU
ANTYPE,0
NLGEOM,1
sstif,on
BF,ALL,TEMP,500
NSUBST,200
ARCLEN,ON
arctrm,u,0.05,,Uz
SOLVE
需要得到513节点的载荷-位移曲线，应如何做，位移为z向，force为x向
谢谢各位指点