*HEADING
: *DSLOAD FOR RIGID ELEMENTS [R3D4]
*NODE,NSET=ALL
1, 0., 0.
3, 7., 0.
7, 0., 7.
9, 7., 7.
*NODE
100,3.5,3.5
*NSET,NSET=LEFT
1, 7
*NSET,NSET=BOT
1, 3
*ELEMENT,ELSET=ELEMS,TYPE=R3D4
1, 1,3,9,7
*surface, NAME=TOP
 ELEMS,SPOS
*surface, NAME=BOT
 ELEMS,SNEG
*RIGID BODY, ELSET=ELEMS, REF=100
2.0, 
*BOUNDARY
100,1,6
*STEP,PERTURBATION
*STATIC
*DSLOAD
 TOP,P,1000.
*EL PRINT
 LOADS,
*NODE PRINT
 RF, 
*EL FILE
 LOADS,
*NODE FILE
 RF, 
*END STEP
*STEP,PERTURBATION
*STATIC
*DSLOAD
 BOT,HP,-3000.,7.,0.
*END STEP
*STEP,NLGEOM
*STATIC
1.0,1.0
*DSLOAD
 BOT,P,-1000.
*EL FILE,FREQ=999
 LOADS,
*NODE FILE,FREQ=999
 RF, 
*END STEP
*STEP,NLGEOM
*STATIC
0.1,1.0
*BOUNDARY
100,4,4,1.5707963268
*END STEP