*HEADING
: SIMPLE CONTACT TEST, 3-D SMALL SLIDING, DEFORMABLE
** C3D20, C3D15, S8R5
** Contact Features Tested:
**	*CONTACT INTERFERENCE w/SHRINK, *FRICTION,
**      *CHANGE FRICTION (mu=0 and mu=0.3),
**	*surface,type=node
**    NOTE: BOTH FRICTION STEPS ARE PERTURBATION STEPS
*RESTART,WRITE, FREQ=6
*NODE
1,   1., 0.,    5.
3,   1.,  1.,   5.
4,   0.5, 0.,   5.
6,   0.5, 1.,   5.
7,   0.,  0.,   5.
9,   0.,  1.,   5.
501,   1.2, -0.2, 9.9
503,   1.2, 1.2,  9.9
504,   0.5, -0.2, 9.9
506,   0.5, 1.2,  9.9
507,  -0.2, -0.2, 9.9
509,  -0.2, 1.2,  9.9
*NGEN,NSET=BOTBR
1, 3
4, 6
7, 9
*NCOPY,OLDSET=BOTBR,NEWSET=N2,SHIFT,CHANGE=10
0.0000,0.00000,2.50000

*NCOPY,OLDSET=N2,NEWSET=N3,SHIFT,CHANGE=10
0.0000,0.00000,2.50000

*NSET,NSET=NBRICK
BOTBR,N2,N3
*NCOPY,OLDSET=NBRICK,NEWSET=NWEDGE,SHIFT,CHANGE=100
0.000,2.000, 0.0000

*NCOPY,OLDSET=NWEDGE,NEWSET=NSHELL,SHIFT,CHANGE=100
0.000,2.000, 0.0000

**
*NGEN, NSET=T1
501,503
504,506
507,509
*NCOPY,OLDSET=T1,NEWSET=T2,SHIFT,CHANGE=10
0.0000,0.00000,2.50000

*NCOPY,OLDSET=T2,NEWSET=T3,SHIFT,CHANGE=10
0.0000,0.00000,2.50000

*NSET, NSET=TBRK
T1,T2,T3
**
*NCOPY,OLDSET=TBRK,NEWSET=TWEDGE,SHIFT,CHANGE=100
0.000,2.000, 0.0000

*NCOPY,OLDSET=TWEDGE,NEWSET=TSHELL,SHIFT,CHANGE=100
0.000,2.000, 0.0000

**
**  BRICK ELEMENTS:
*ELEMENT,TYPE=C3D20
1,1,3,9,7,21,23,29,27,2,6,8,4,22,26,28,24,
11,13,19,17
*ELGEN,ELSET=EBRICK
1,2,500,10
**
**  WEDGE ELEMENTS:
*ELEMENT,TYPE=C3D15
2,101,107,121,103,109,123,104,114,111,106,116,113,
102,108,122
3,107,127,121,109,129,123,117,124,114,119,126,116,
108,128,122
*ELGEN,ELSET=EWEDGE
2,2,500,10
3,2,500,10
**
**  SHELL ELEMENTS:
*ELEMENT,TYPE=S8R5,ELSET=ESHELL
4,221,223,229,227,222,226,228,224
14,701,703,709,707,702,706,708,704
**
*SOLID SECTION,ELSET=EBRICK,MATERIAL=MAT
*SOLID SECTION,ELSET=EWEDGE,MATERIAL=MAT
*SHELL SECTION,ELSET=ESHELL,MATERIAL=MAT,TEMP=3
0.1,
**
*MATERIAL,NAME=MAT
*ELASTIC
3.0E6,0.3
*EXPANSION
1.0E-6,
**
*surface,NAME=SURF1A
1,S2
*surface,NAME=SURF1B
11,S1
*surface,NAME=SURF2A
3,S4
*surface,NAME=SURF2B
12,S3
*surface,NAME=SURF3B
14,SNEG
*surface,NAME=SURF3A
4,SPOS
*CONTACT PAIR,INTERACTION=CNTCT,SMALL, TYPE=SURFACE TO SURFACE
SURF1A,SURF1B
SURF2A,SURF2B
SURF3A,SURF3B
*SURFACE INTERACTION,NAME=CNTCT
*FRICTION
0.,
**
*NSET,NSET=BOTTOM,GEN
1,  9
101,109
*NSET,NSET=TOP,GEN
521,529
621,629
*NSET,NSET=TOPSHL,GEN
701,709
*NSET, NSET=BOTSHL, GEN
221,229
**
*ELEMENT,TYPE=SPRING1,ELSET=SPR
903,703
901,701
907,707
909,709
921,221
923,223
929,229
927,227
*SPRING,ELSET=SPR
3,
1.0E-2,
**
*BOUNDARY
TOP, 1,3
BOTTOM, 1,3
**221,1,2
221,4,6
**227,1,2
TOPSHL,1,2
BOTSHL,1,2
**
** step 1: Shrink fit with *CONTACT INTERFERENCE.
** 	   Establish base state.
**
*STEP ,NLGEOM
*STATIC
0.25,1.
*CONTROLS, PARAMETER=FIELD
,2.E-02
*CONTACT INTERFERENCE, SHRINK
SURF1A, SURF1B
*CONTACT INTERFERENCE, SHRINK
SURF2A, SURF2B
*CONTACT INTERFERENCE, SHRINK
SURF3A, SURF3B
*ENERGY FILE,FREQ=4
*CONTACT PRINT,SLAVE=SURF1A,MASTER=SURF1B
*CONTACT PRINT,SLAVE=SURF2A,MASTER=SURF2B
*CONTACT PRINT,SLAVE=SURF3A,MASTER=SURF3B
*CONTACT FILE,SLAVE=SURF3A,MASTER=SURF3B,F=4
*CONTACT FILE,SLAVE=SURF2A,MASTER=SURF2B,F=4
*CONTACT FILE,SLAVE=SURF1A,MASTER=SURF1B,F=4
*EL FILE ,FREQ=4
S,
E,
*NODE FILE,FREQ=4
RF,
*ENERGY PRINT, FREQ=4
*EL PRINT ,SUM=NO, FREQ=4
S,
E,
*NODE PRINT,SUM=NO, FREQ=4
RF,
*OUTPUT,FIELD,VARIABLE=PRESELECT
*CONTACT OUTPUT
 CFORCE,
*OUTPUT,HISTORY,VARIABLE=PRESELECT
*END STEP
**
** step 2: slide top cube to the right w/o friction
**
*STEP,PERT
*STATIC
*CONTROLS, PARAMETER=FIELD, RESET
*BOUNDARY
TOP,1,,0.1
TOPSHL,1,, 0.1
*ENERGY FILE,FREQ=6
*EL FILE ,FREQ=6
S,
E,
*NODE FILE,FREQ=6
RF,
*CONTACT FILE,SLAVE=SURF3A,MASTER=SURF3B,F=6
*CONTACT FILE,SLAVE=SURF2A,MASTER=SURF2B,F=6
*CONTACT FILE,SLAVE=SURF1A,MASTER=SURF1B,F=6
*ENERGY PRINT, FREQ=6
*EL PRINT ,SUM=NO, FREQ=6
S,
E,
*NODE PRINT,SUM=NO, FREQ=6
RF,
*OUTPUT,FIELD,VARIABLE=PRESELECT
*CONTACT OUTPUT
 CFORCE,
*END STEP
**
** step 3: change surface friction
**
*STEP,NLGEOM
*STATIC
1.0,1.0
*CHANGE FRICTION,INTERACTION=CNTCT
*FRICTION
0.3,
*OUTPUT,FIELD,VARIABLE=PRESELECT
*CONTACT OUTPUT
 CFORCE,
*ENDSTEP
**
** step 4: slide to the left w/ friction
**
*STEP,PERT
*STATIC
*BOUNDARY
TOP,1,,-0.1
*ENERGY FILE,FREQ=6
*EL FILE, FREQ=6
S,
E,
*NODE FILE, FREQ=6
U,
*CONTACT PRINT,SLAVE=SURF1A,MASTER=SURF1B, FREQ=6
*CONTACT PRINT,SLAVE=SURF2A,MASTER=SURF2B, FREQ=6
*CONTACT PRINT,SLAVE=SURF3A,MASTER=SURF3B, FREQ=6
*CONTACT FILE,SLAVE=SURF3A,MASTER=SURF3B,F=6
*CONTACT FILE,SLAVE=SURF2A,MASTER=SURF2B,F=6
*CONTACT FILE,SLAVE=SURF1A,MASTER=SURF1B,F=6
*OUTPUT,FIELD,VARIABLE=PRESELECT
*CONTACT OUTPUT
 CFORCE,
*ENDSTEP