*HEADING
 :  [FRAME2D]
 ELASTIC FRAME ELEMENT WITH MARSHALL STRUT ENVELOPE  
*NODE,NSET=CENTER
2,10.,10.,0.
*NODE,NSET=BOUN
1,0.,0.,0.
3,20.,20.,0.
4,10.,0.,0.
*ELEMENT, TYPE=FRAME2D, ELSET=ALL
1,1,2
2,2,3
3,2,4
*FRAME SECTION,SECTION=PIPE,ELSET=ALL,BUCKLING,PINNED,YIELDSTRESS=51.9E3
.2,.01
0,0,-1
3.0E6,1.5E6
*BOUNDARY
1,1,2
3,1,2
4,1,2
*RESTART,WRITE
*STEP,NLGEOM,INC=1000
*STATIC,RIKS
0.01,1.0,,,1.
*CLOAD
2,1,100.
*NODE PRINT, NSET=CENTER
U, 
*NODE FILE,NSET=CENTER
U, 
*NODE PRINT, NSET=BOUN
RF, 
*NODE FILE,NSET=BOUN
RF, 
*EL PRINT, ELSET=ALL
SF, 
*EL FILE, ELSET=ALL
SF, 
*ENERGY PRINT
*ENERGY FILE
*END STEP