*HEADING
 SQUARE PLATE - ELASTIC BUCKLING  ( BUCKLE )-S8R 2 x 2  
*NODE
101, 
105,1.
501,0.,1.
505,1.,1.
*NGEN,NSET=XSYM
101,501,100
*NGEN,NSET=XEDG
105,505,100
*NFILL
XSYM,XEDG,4,1
*NGEN,NSET=YSYM
101,105
*NGEN,NSET=YEDG
501,505
*ELEMENT,TYPE=S8R,ELSET=ONE
1,101,103,303,301,102,203,302,201
*ELGEN,ELSET=ONE
1,2,2,1,2,200,2
*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