*HEADING
: SIMPLE CONTACT TEST, FINITE SLIDING CONTACT WITHOUT FRICTION, RIGID 
** Contact Features Tested: 
**	*FRICTION, *CHANGE FRICTION (mu=0 and mu=0.3)
*NODE, NSET=BLOCK
 1,  4., 1., 4.
 2,  4., 1., 1.
 3,  2., 1., 2.
 4,  2., 1., 3.
 5,  4., 3., 4.
 6,  4., 3., 1.
 7,  2., 3., 2.
 8,  2., 3., 3.
*NODE
 9999, 0., 0., 0.
*NSET,NSET=TOP
 5,6,7,8
*NSET,NSET=BOT
 1,2,3,4
*NSET,NSET=LEFT
 3,4,7,8
*NSET,NSET=RIGHT
 1,2,5,6
*ELEMENT, TYPE=C3D8, ELSET=BLOCK
 1,  1,2,3,4,5,6,7,8
*SOLID SECTION, ELSET=BLOCK, MATERIAL=SOFT
*MATERIAL, NAME=SOFT
*ELASTIC
 30.E6, 0.3
*rigid body,analytical surface=BSURF, REFNODE=9999 
*surface,TYPE=CYLINDER, NAME=BSURF
 0., 0., 10.,   10., 0., 10.
 0., 0., -10.
 START, 0., 0.
 LINE, 10., 0.
*surface,NAME=ASURF
BLOCK,S1
*CONTACT PAIR,INTERACTION=SMOOTH
ASURF,BSURF
*SURFACE INTERACTION,NAME=SMOOTH
*FRICTION
0.0, 
**
** Step 1:  Bring block into contact and push against rigid surface
**
*STEP,AMP=RAMP
*STATIC
 1., 1., 0.1
*CONTROLS,PARAMETERS=FIELD
 0.000001,
*BOUNDARY
 1, 1
 2, 1
 2, 3
 9999, 1,6
 TOP, 2,, -1.00001
*PRINT, CONTACT=YES
*CONTACT PRINT,SECONDARY=ASURF
*CONTACT FILE,SECONDARY=ASURF
*EL FILE
 S,
*NODE FILE
U, 
*END STEP
**
** Step 2: Apply normal load on top surface of block
**
*STEP,AMP=RAMP
*STATIC
 1., 1., 0.01
*BOUNDARY,OP=NEW
 1, 1
 2, 1
 2, 3
 9999, 1,6
*DLOAD
 BLOCK, P2, 100.E3
*PRINT, CONTACT=YES
*CONTACT FILE,SECONDARY=ASURF
*EL FILE
 S,
*NODE FILE
U, 
*END STEP
**
** Step 3: Slide block by fixing one end and pulling on the other
**
*STEP,AMP=RAMP,NLGEOM
*STATIC
 0.1, 1., 0.001
*BOUNDARY,OP=NEW
 LEFT,1,,-2.0
 RIGHT,1
 6,3
 9999, 1,6
*CONTACT FILE,SECONDARY=ASURF
*EL FILE
 S,
*NODE FILE
U, 
*END STEP
**
** step 4: change surface friction
**
*STEP,NLGEOM
*STATIC
1.0,1.0
*CHANGE FRICTION,INTERACTION=SMOOTH
*FRICTION
0.0, 
*ENDSTEP
**
** step 5: slide to the left w/ friction
**
*STEP,NLGEOM
*STATIC
*BOUNDARY,OP=NEW
 LEFT,1,,-2.0
 RIGHT,1,,-2.0
 6,3
 9999, 1,6
*CONTACT FILE,SECONDARY=ASURF
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SECONDARY=ASURF,MAIN=BSURF
*CONTACT PRINT,SECONDARY=ASURF,MAIN=BSURF
*PRINT,CONTACT=YES
*ENDSTEP