*HEADING
: SIMPLE CONTACT TEST, SMALL SLIDING, CPE8
** Contact Features Tested:
**	*CONTACT INTERFERENCE, *FRICTION, *CHANGE FRICTION (mu=0 and mu=0.3)
**      BOTH FRICTION STEPS ARE PERTURBATION STEPS
** Dynamic Features Tested:
**      *STEADY STATE DYNAMICS,DIRECT
**      *FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
**      *STEADY STATE DYNAMICS,SUBSPACE PROJECTION
*AMPLITUDE,NAME=CONST
0,1,1,1
*RESTART,WRITE, FREQ=4
**
*NODE, Nset=ODB_NSET
1,1.,
3,2.,
9,2.,1.2
7,1.,1.2
11,0.,1.
13,3.,1.
19,3.,3.
17,0.,3.
*NGEN,NSET=BOT
1,3
*NGEN, Nset=ODB_NSET
3,9,3
7,9
1,7,3
11,13
13,19,3
11,17,3
*NGEN,NSET=TOP
17,19
*ELEMENT,TYPE=CPE8,ELSET=BOT
1,1,3,9,7,2,6,8,4
*ELEMENT,TYPE=CPE8,ELSET=TOP
3,11,13,19,17,12,16,18,14
**
*SOLID SECTION,ELSET=BOT,MATERIAL=MAT
*SOLID SECTION,ELSET=TOP,MATERIAL=MAT
*MATERIAL,NAME=MAT
*ELASTIC
1.E5,.3
*DENSITY
10.0, 
*SURFACE INTERACTION,NAME=SLIDE
 1., 
*FRICTION
0., 
*surface,NAME=BOTS
BOT,S3
*surface,NAME=TOPS
TOP,S1
*CONTACT PAIR,INTERACTION=SLIDE, SMALL SLIDING
BOTS,TOPS
*BOUNDARY
BOT, 1,2
TOP, 1,2
**
** step 1: Shrink fit with *CONTACT INTERFERENCE.
** 	   Establish base state.
**
**
** Sets added by addodb
**
*Elset,Elset=ODB_ESET
BOT, TOP
**
**
*Nset, Nset=ODB_NSET
ODB_NSET, BOT, TOP
**
**
*STEP,INC=20,NLGEOM
*STATIC
0.2,1.,0.2,0.2
*CONTACT INTERFERENCE, SHRINK
BOTS,TOPS
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SLAVE=BOTS,MASTER=TOPS
*CONTACT PRINT,SLAVE=BOTS,MASTER=TOPS
*PRINT,CONTACT=YES
*OUTPUT,FIELD,VARIABLE=PRESELECT,OP=ADD,FREQUENCY=4
*OUTPUT,FIELD, OP=ADD
*ELEMENT OUTPUT
S, 
*OUTPUT,HISTORY,OP=ADD
*ELEMENT OUTPUT, Elset=ODB_ESET
S, 
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT
U, 
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT, Nset=ODB_NSET
U, 
*OUTPUT,FIELD, OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*OUTPUT,HISTORY,OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*END STEP
**
** step 2: slide to the right w/o friction, linear perturbation
**
*STEP,PERT,NLGEOM
*STATIC
*BOUNDARY,OP=MOD
BOT,1,1, 0.1
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SLAVE=BOTS,MASTER=TOPS
*CONTACT PRINT,SLAVE=BOTS,MASTER=TOPS
*PRINT,CONTACT=YES
*OUTPUT,FIELD, OP=ADD
*ELEMENT OUTPUT
S, 
*OUTPUT,HISTORY,OP=ADD
*ELEMENT OUTPUT, Elset=ODB_ESET
S, 
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT
U, 
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT, Nset=ODB_NSET
U, 
*OUTPUT,FIELD, OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*OUTPUT,HISTORY,OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*END STEP
**
** step 3: change surface friction
**
*STEP,NLGEOM
*STATIC
1.0,1.0
*CHANGE FRICTION,INTERACTION=SLIDE
*FRICTION
0.3, 
*END STEP
**
** step 4: slide to the left w/ friction, linear perturbation
**
*STEP,NLGEOM,PERT
*STATIC
*BOUNDARY
BOT,1,,-0.1
*EL FILE
S, 
*NODE FILE
U, 
*CONTACT FILE,SLAVE=BOTS,MASTER=TOPS
*CONTACT PRINT,SLAVE=BOTS,MASTER=TOPS
*PRINT,CONTACT=YES
*OUTPUT,FIELD, OP=ADD
*ELEMENT OUTPUT
S, 
*OUTPUT,HISTORY,OP=ADD
*ELEMENT OUTPUT, Elset=ODB_ESET
S, 
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT
U, 
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT, Nset=ODB_NSET
U, 
*OUTPUT,FIELD, OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*OUTPUT,HISTORY,OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL,SLAVE=BOTS,MASTER=TOPS
*END STEP
**
** step 5: Steady state dynamics, direct analysis
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
4,20,5
*BOUNDARY
BOT,2,,0.01
*NODE FILE
U, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT
U, 
RF, 
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT, Nset=ODB_NSET
U, 
RF, 
*OUTPUT,FIELD, OP=ADD
*ELEMENT OUTPUT
E, 
S, 
*OUTPUT,HISTORY,OP=ADD
*ELEMENT OUTPUT, Elset=ODB_ESET
E, 
S, 
*OUTPUT,FIELD, OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL
*OUTPUT,HISTORY,OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL
*END STEP
**
** step 6: frequency extraction ->all modes are extracted
**
*STEP
*FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
14,,,-1,
*BOUNDARY,BASE NAME=SHAKE
BOT,2,2
*CONTACT FILE,FREQ=0
*NODE FILE,F=0
*EL FILE,F=0
*NODE PRINT,F=0
*EL PRINT,F=0
*MODAL FILE
*OUTPUT,FIELD, OP=NEW,Frequency=0
*NODE OUTPUT
*ELEMENT OUTPUT
*OUTPUT,HISTORY,OP=NEW,Frequency=0
*END STEP
**
** step 7: Steady state dynamics, subspace projection
**
*STEP
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,INTERVAL=RANGE
4,20,5
*BASE MOTION,BASE NAME=SHAKE,AMPLITUDE=CONST,DOF=2,TYPE=DISPLACEMENT,SCALE=0.01
*NODE FILE
U, 
RF, 
*EL FILE
E, 
S, 
*MODAL FILE
BM, 
*CONTACT FILE
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT
U, 
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT, Nset=ODB_NSET
U, 
*OUTPUT,FIELD, OP=ADD
*ELEMENT OUTPUT
E, 
S, 
*OUTPUT,HISTORY,OP=ADD
*ELEMENT OUTPUT, Elset=ODB_ESET
E, 
S, 
*OUTPUT,FIELD, OP=ADD
*MODAL OUTPUT,VARIABLE=ALL
BM, 
*OUTPUT,FIELD, OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL
*OUTPUT,HISTORY,OP=ADD
*CONTACT OUTPUT, VARIABLE=ALL
*END STEP