*HEADING
: SIMPLE CONTACT TEST, FINITE SLIDING CONTACT WITHOUT FRICTION, RIGID 
** Contact Features Tested: 
**	*FRICTION, *CHANGE FRICTION (mu=0 and mu=0.3)
*NODE
1, 6.,0.
3, 7.,0.
1000,0.
*NGEN
1,3
*ELEMENT,TYPE=B22,ELSET=BEAM
1, 1,2,3
*BEAM SECTION,SECT=RECT,ELSET=BEAM,MATERIAL=MAT1
.25,.25
*MATERIAL,NAME=MAT1
*ELASTIC
30.E6,.3
*RIGID BODY,ANALYTICAL SURFACE=BSURF,REFNODE=1000
*SURFACE,TYPE=SEGMENTS,NAME=BSURF
START,5.5, 0.
LINE, 7.5, 0.
*SURFACE,NAME=ASURF
BEAM,SPOS
*CONTACT PAIR,INTERACTION=SMOOTH
ASURF,BSURF
*SURFACE INTERACTION,NAME=SMOOTH
1., 
*FRICTION
0.0, 
*STEP
*STATIC
*CONTACT PRINT,SECONDARY=ASURF
*CONTACT FILE,SECONDARY=ASURF
*EL FILE
 S,
*EL PRINT
 S,
*NODE FILE
U, 
*NODE PRINT,FREQ=0
*DLOAD
 1,PY,-500.
*BOUNDARY
1,1
1,6
3,6
1000,1,2
1000,6
*END STEP
*STEP,NLGEOM
  LARGE DISPLACEMENT ANALYSIS
*STATIC
 .5,1.
*DLOAD
1,PY,-500.
*BOUNDARY
1,1
1,6
3,6
1000,1,2
1000,6
*EL FILE
 S,
*EL PRINT
 S,
*NODE FILE
U, 
*END STEP
**
** step 3: change surface friction
**
*STEP,NLGEOM
*STATIC
1.0,1.0
*CHANGE FRICTION,INTERACTION=SMOOTH
*FRICTION
0.3, 
*ENDSTEP
**
** step 4: slide to the left w/ friction
**
*STEP,NLGEOM
*STATIC
*BOUNDARY
1,1,,0.1
2,1,,0.1
3,1,,0.1
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SECONDARY=ASURF,MAIN=BSURF
*CONTACT PRINT,SECONDARY=ASURF,MAIN=BSURF
*PRINT,CONTACT=YES
*ENDSTEP