*HEADING
: SIMPLE CONTACT TEST, FINITE SLIDING CONTACT WITH ZERO FRICTION, DEFORMABLE
*AMPLITUDE,NAME=CONST
0,1,1,1
*AMPLITUDE,NAME=ZERO
0,0,1,0
*NODE
1,0.0,0.0
7,7.5,0.0
11,,2.
17,7.5,2.0
101,0.5,2.1
103,2.25,2.1
111,0.5,4.1
113,2.25,4.1
*NGEN,NSET=BASE
1,7,2
*NGEN,NSET=TOP
111,113,2
*NGEN
11,17,2
101,103
*ELEMENT,TYPE=CPE4,ELSET=STEEL
1,1,3,13,11
11,101,103,113,111
*ELGEN,ELSET=STEEL
1,3,2
*ELSET,ELSET=ETOP
11, 
*ELSET,ELSET=EBOT,GENERATE
1,3,1
*surface,NAME=ASURF
ETOP,S1
*surface,NAME=BSURF
EBOT,S3
*CONTACT PAIR,INTERACTION=ROUGH,TYPE=SURFACE TO SURFACE
ASURF,BSURF
*SURFACE INTERACTION,NAME=ROUGH
*SOLID SECTION,ELSET=STEEL,MATERIAL=STEEL
*MATERIAL,NAME=STEEL
*ELASTIC
 30.E6,0.3
*DENSITY
 10.0, 
******************************
*STEP,NLGEOM,UNSYMM=YES
  CONTACT
*STATIC,DIRECT
 0.67,1.
*CONTROLS,PARAMETERS=FIELD
1.0E-6, 
*BOUNDARY
 BASE,2
1,1
11,1
TOP,2,,-.15
TOP,1
*CONTACT PRINT,SLAVE=ASURF
*CONTACT FILE,SLAVE=ASURF,FREQ=5
*PRINT,CONTACT=YES
*EL PRINT
S,E
*NODE PRINT
U,RF
*EL FILE,FREQ=5
S,E
*NODE FILE,FREQ=5
U,RF
*END STEP
*STEP,NLGEOM
  MOVE TOP ACROSS
*STATIC
 1.,10.,1.
*BOUNDARY,OP=NEW
 BASE,2
1,1
11,1
TOP,2,,-.15
TOP,1,,4.
*END STEP
**
*STEP, PERTURBATION
  LIFT TOP, ENOUGH TO PRODUCE TENSILE CONTACT STRESS
*STATIC
*BOUNDARY
 BASE,2
1,1
11,1
TOP,2,,0.07
TOP,1
*CONTACT PRINT,SLAVE=ASURF
*CONTACT FILE,SLAVE=ASURF
*EL FILE
S,E
*NODE FILE
U,RF
*END STEP
**
** step 5: Steady state dynamics, direct analysis
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
20,100,5
*BOUNDARY
BASE,2
1,1
11,1
TOP,2
TOP,1,1, 0.01
*NODE FILE
U, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*END STEP
**
** step 6: frequency extraction ->all modes are extracted
**
*STEP
*FREQUENCY,EIGENSOLVER=LANCZOS
12,
*BOUNDARY
BASE,2
TOP,2,2
*BOUNDARY
TOP,1,1
*BOUNDARY,BASE NAME=ZERO
1,1
11,1
*CONTACT FILE,FREQ=0
*NODE FILE,F=0
*EL FILE,F=0
*NODE PRINT,F=0
*EL PRINT,F=0
*MODAL FILE
*END STEP
**
** step 7: Steady state dynamics, subspace projection
**
*STEP
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,INTERVAL=RANGE
20,100,5
*BASE MOTION,BASE NAME=ZERO, AMPLITUDE=ZERO ,DOF=1,TYPE=DISPLACEMENT
*BASE MOTION,AMPLITUDE=CONST,DOF=1,TYPE=DISPLACEMENT,SCALE=0.01
*NODE FILE
TU, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*END STEP