*HEADING
LATERAL BUCKLING: B32OS, *BEAM SECTION, SECTION=I
*NODE
*ELEMENT,TYPE=B32OS
*ELGEN,ELSET=BEAM
*BEAM SECTION,SECTION=I,ELSET=BEAM,MATERIAL=MAT
 0.345,0.69, 0.3,0.3, 0.027,0.027, 0.0145
 0.0,-1.0,0.0
*MATERIAL,NAME=MAT
*ELASTIC
 2.1E11,0.3125
*BOUNDARY
 1,1,4
 21,2,4
*STEP,NLGEOM,INC=50
*STATIC,RIKS
 .025, 1., 1.E-4, , ,11,3,-0.3
*DLOAD
BEAM, PZ, -100000.,
*MONITOR,NODE=11,DOF=3
*EL PRINT,FREQUENCY=20
*NODE PRINT,FREQUENCY=5
COORD,
U,
RF  ,
*NODE FILE
U,
*EL FILE,FREQUENCY=25
S,E
SF,
*END STEP