finish
/clear

Dout=89
Din=79
Area=3.1415926535857932*(Dout**2-Din**2)/4
IR=0.25*sqrt(DOUT*DOUT+DIN*DIN)

/prep7
et,1,link180
mp,ex,1,2..1e60
mp,prxy,1,0.3
r,1,Area
n,1,-5,0,0
n,2,0,0,1
n,3,5,0,0
e,1,2
e,2,3
PSPRNG,1,TRAN,1500,-1,,, ,  
PSPRNG,3,TRAN,1500,1,,, ,   
finish

!靜力分析
/SOL 
ANTYPE,0 
NLGEOM,1 
OUTRES,ALL,ALL 
ARCLEN,ON 
ARCTRM,U,3.0,2,uz 
NSUBST,20 
nsel,s,loc,z,0
d,all,uz
nsel,s,loc,z,1
d,all,uy
f,all,fz,-10
allsel
solve
finish

/POST26 
/AXLAB,X,W
/AXLAB,Y,P/Pcr 
NSOL,2,2,U,z,DISP
RFORCE,3,1,F,z,LOAD-DISP 
PROD,2,2, , , , , ,-1,1,1,  
PROD,3,3, , , , , ,0.34632,1,1, 
XVAR,2
PRVAR,2,3 
PLVAR,3