*HEADING
: SIMPLE CONTACT TEST, FINITE SLIDING CONTACT WITHOUT FRICTION, RIGID 
** Contact Features Tested: 
**	*FRICTION, *CHANGE FRICTION (mu=0 and mu=0.3)
*NODE
1, 0.
3, 5.
7, 0., 5.
9, 5., 5.
1000,0.
*NGEN
1,3
7,9
1,7,3
3,9,3
*ELEMENT,TYPE=CPE8,ELSET=SOLID
1, 1,3,9,7,2,6,8,4
*SOLID SECTION,ELSET=SOLID,MATERIAL=MAT1
.25, 
*MATERIAL,NAME=MAT1
*ELASTIC
30.E6,.3
*DENSITY
 10.0, 
*rigid body,analytical surface=BSURF,REFNODE=1000
*surface,TYPE=SEGMENTS,NAME=BSURF
START,0.0, 0.
LINE, 5.5, 0.
*surface,NAME=ASURF
SOLID,S1
*CONTACT PAIR,INTERACTION=SMOOTH
ASURF,BSURF
*SURFACE INTERACTION,NAME=SMOOTH
.25, 
*FRICTION
0.0, 
**
** Step 1: linear geometry analysis
**
*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,P3,250.
*BOUNDARY
1,1
1000,1,2
1000,6
*OUTPUT,FIELD
*NODE OUTPUT
U,
*ELEMENT OUTPUT
S,
*CONTACT OUTPUT,SECONDARY=ASURF,VARIABLE=PRESELECT
*END STEP
**
** Step 2: Nonlinear geometry 
**
*STEP,NLGEOM
  LARGE DISPLACEMENT ANALYSIS
*STATIC
 .5,1.
*DLOAD
1,P3,250.
*BOUNDARY
1,1
1000,1,2
1000,6
*EL FILE
 S,
*EL PRINT
 S,
*NODE FILE
U, 
*OUTPUT,FIELD
*NODE OUTPUT
U,
*ELEMENT OUTPUT
S,
*END STEP
**
** step 3: change surface friction
**
*STEP,NLGEOM
 CHANGE SURFACE FRICTION
*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
7,1,,0.1
8,1,,0.1
9,1,,0.1
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SECONDARY=ASURF,MAIN=BSURF
*CONTACT PRINT,SECONDARY=ASURF,MAIN=BSURF
*PRINT,CONTACT=YES
*OUTPUT,FIELD
*NODE OUTPUT
U,
*ELEMENT OUTPUT
S,
*CONTACT OUTPUT,SECONDARY=ASURF,MAIN=BSURF,VARIABLE=PRESELECT
*ENDSTEP
**
** step 5: Steady state dynamics, direct analysis
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
20,80,5
*DLOAD
1,P3,250.
*BOUNDARY
1,1
1000,1,2
1000,6
*EL PRINT
 S,
*NODE FILE
U, 
RF, 
*EL FILE
E,
S,
*CONTACT FILE
*OUTPUT,FIELD
*NODE OUTPUT
U,
RF,
*ELEMENT OUTPUT
S,
E,
*CONTACT OUTPUT,SECONDARY=ASURF,MAIN=BSURF,VARIABLE=PRESELECT
*END STEP
**
** step 6: frequency extraction -> 10 modes are extracted
**
*STEP
*FREQUENCY, eigensolver=lanczos, SIM=NO
10, , ,
*BOUNDARY
 1,1
 1000,1,2
 1000,6
*MODAL FILE
*CONTACT FILE,FREQ=0
*NODE FILE,F=0
*EL FILE,F=0
*NODE PRINT,F=0
*EL PRINT,F=0
*END STEP
**
** step 7: Steady state dynamics, subspace projection
**
*STEP
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,INTERVAL=RANGE
20,80,5
*DLOAD
 1,P3,250.
*NODE FILE
U, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*OUTPUT,FIELD
*NODE OUTPUT
U,
RF,
*ELEMENT OUTPUT
S,
E,
*CONTACT OUTPUT,SECONDARY=ASURF,MAIN=BSURF,VARIABLE=PRESELECT
*END STEP