关于桁架的优化设计

chanjoy1988

*CREATE,SCRATCH
B=1
A1=1E-3
A2=1E-3
A3=1E-3

/PREP7
ET,1,LINK1
R,1,A1
R,2,A2
R,3,A3
MP,EX,1,2.2E11
N,1,-B,0,0
N,2,0,0,0
N,3,B,0,0
N,4,0,-1,0
E,1,4
REAL,2
E,2,4
REAL,3
E,3,4
FINISH

/SOLU
D,1,ALL,0,,3
F,4,FX,200000
F,4,FY,-200000
SOLVE
FINISH

/POST1
SET,LAST
ETABLE,EVOL,VOLU
SSUM
*GET,VTOT,SSUM,,ITEM,EVOL
RHO=7800
WT=RHO*VTOT
ETABLE,SIG,LS,1
*GET,SIG1,ELEM,1,ETAB,SIG
*GET,SIG2,ELEM,2,ETAB,SIG
*GET,SIG3,ELEM,3,ETAB,SIG
SIG1=ABS(SIG1)
SIG2=ABS(SIG2)
SIG3=ABS(SIG3)
EPLOT
FINISH
*END

*USE,SCRATCH
*STATUS


/OPT
OPANL,SCRATCH
OPVAR,B,DV,0.4,1
OPVAR,A1,DV,1E-6,1E-3
OPVAR,A2,DV,1E-6,1E-3
OPVAR,A3,DV,1E-6,1E-3
OPVAR,SIG1,SV, , 260E6
OPVAR,SIG2,SV, , 260E6
OPVAR,SIG3,SV, , 260E6
OPVAR,WT,OBJ, , , 0.2
OPTYPE,SUBP
OPSUBP,30
OPPRNT,ON
OPEXE
OPLIST,ALL
哪位帮我看看，做出来的结果截个图回复一下
问题出在哪儿，是边界条件的设置问题还是其他?万分感谢！

zp4655958

行啊！！！！！