*HEADING
 SQUARE PLATE - ELASTIC BUCKLING  ( BUCKLE )-S8R 2 x 2
*NODE
*NGEN,NSET=XSYM
*NGEN,NSET=XEDG
*NFILL
XSYM,XEDG,4,1
*NGEN,NSET=YSYM
*NGEN,NSET=YEDG
*ELEMENT,TYPE=S8R,ELSET=ONE
*ELGEN,ELSET=ONE
*MATERIAL ,NAME=PLATE
*ELASTIC
1.E8,.3
*SHELL SECTION ,MATERIAL=PLATE,ELSET=ONE
.01,3
*BOUNDARY
YSYM,YSYMM
XSYM,XSYMM
YEDG,3
YEDG,5
XEDG,3
XEDG,4
XEDG,6
*STEP
*BUCKLE
3,
*CLOAD
105,1,-8.33333333
205,1,-33.3333333
305,1,-16.66666667
405,1,-33.3333333
505,1,-8.3333333
*NODE PRINT
U,
RF,
*MODAL FILE
*END STEP