*HEADING
 RING BUCKLE EIGENVALUE ESTIMATE ( 2 S8R )
*NODE,NSET=Y0
*NODE,NSET=END
*NGEN,LINE=C,NSET=TOP
*NGEN,LINE=C,NSET=BOT
*NGEN,LINE=C
*ELEMENT,TYPE=S8R,ELSET=ONE
*ELGEN,ELSET=RING
*SHELL SECTION,MATERIAL=A1,ELSET=RING
1.,3
*MATERIAL,NAME=A1
*ELASTIC
30.E6,0.
*TRANSFORM,NSET=END
*STEP
*BUCKLE
1,
*DLOAD
RING,P,-1.
*BOUNDARY
TOP,3,5
BOT,3,5
Y0,YSYMM
END,YSYMM
*BOUNDARY,LOAD CASE=2, OP=NEW
TOP,3,5
BOT,3,5
Y0,YSYMM
END,1
END,3
END,5
*EL PRINT,ELSET=ONE
S,
*MODAL FILE
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*END STEP