*HEADING
: FINITE SLIDING CONTACT   C3D5
VERIFICATION FOR FRICTION CHANGE
*AMPLITUDE,NAME=CONSTA
0,0.048,1,0.048
*AMPLITUDE,NAME=CONSTB
0,0.060,1,0.060
*AMPLITUDE,NAME=CONSTC
0,-0.064,1,-0.064
*NODE
1, 
7,7.5
*NGEN, NSET=E1
1,7
*NCOPY, OLDSET=E1, NEWSET=E2, SHIFT, CHANGE=20
0., 0., 2.5

*NFILL, NSET=BOT
E1,E2,2,10
*NCOPY, OLDSET=BOT, NEWSET=TOP, SHIFT, CHANGE=200
0.,2.,0.

*NFILL, NSET=BALL
BOT,TOP,2,100
*NODE
501, 0.5, 2.1, 0.25
503, 2.25, 2.1, 0.25
*NGEN, NSET=S1
501,503
*NCOPY, OLDSET=S1, NEWSET=S2, SHIFT, CHANGE=20
0., 0., 2.0

*NFILL, NSET=SLI_BOT
S1,S2,2,10
*NCOPY, OLDSET=SLI_BOT, NEWSET=SLI_TOP, SHIFT, CHANGE=200
0.,2.0,0.

*NFILL, NSET=SALL
SLI_BOT,SLI_TOP,2,100
*NSET, NSET=BC1
1,21,201,221
*NSET, NSET=NALL
BALL, SALL
*NMAP, NSET=NALL, TYPE=RECTANGULAR
0,0,0,.8,.0,.6
.48,.6,-.64
*TRANSFORM, NSET=NALL
.8,.0,.6,.48,.6,-.64
*ELEMENT, TYPE=C3D5
1, 1, 21, 23,  3,223
2, 1,201,221, 21,223
3, 1,  3,203,201,223
4, 3, 23, 25,  5,223
5, 3,  5,205,203,223
6, 5, 25,225,205,223
7, 5,205,225, 25,227
8, 5, 25, 27,  7,227
9, 5,  7,207,205,227
100, 501,521,523,503, 723
101, 501,701,721,521, 723
102, 501,503,703,701, 723
*ELSET,ELSET=BLOCK,GEN
1,9
*ELSET, ELSET=SLIDER
100,101,102
*ELSET, ELSET=EALL
SLIDER, BLOCK
*SOLID SECTION, ELSET=EALL, MATERIAL=MAT
*MATERIAL, NAME=MAT
*ELASTIC
30.0E6, 0.3
*DENSITY
10.0, 
*ELSET, ELSET=BTOP3
2,7
*ELSET, ELSET=BTOP4
3,5,6,9
*ELSET, ELSET=SBOT
100
*surface, NAME=SL1
SBOT, S1
*surface, NAME=MA1
BTOP3, S3
BTOP4, S4
*CONTACT PAIR, INTERACTION=INT
SL1, MA1
*SURFACE INTERACTION, NAME=INT
*FRICTION
0.0, 
*BOUNDARY
BC1,1
BOT,2,3
SLI_TOP,3
*STEP, NLGEOM, INC=100, UNSYMM=YES
 FIRST COMPRESS
*STATIC, DIRECT
0.67,1.0
*CONTROLS, PARAMETER=FIELD
1.0E-6, 
*BOUNDARY
SLI_TOP,1
SLI_TOP,2,2,-.15
*EL PRINT, F=0
*NODE PRINT, F=0
*EL FILE,FREQ=5
S,E,
ELEN, 
*NODE FILE,FREQ=5
U,RF
*CONTACT FILE, MASTER=MA1
CSTRESS,CDISP
CAREA, 
CFN,CFS
CMN,CMS
CFT,CMT
XN,XS,XT
*END STEP
*STEP, NLGEOM, INC=100, UNSYMM=YES
 SLIDE ACROSS TOP - MODIFY FRICTION
*STATIC
0.1,1.0
*BOUNDARY
SLI_TOP,2,2,-.15
SLI_TOP,1,1,4.
*CHANGE FRICTION, INTERACTION=INT
*FRICTION
0.3, 
*END STEP
**
** step 4: Steady state dynamics, direct analysis
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
20,100,5
*BOUNDARY,OP=NEW
BC1,1
BOT,2,3
SLI_TOP,1
SLI_TOP,2,2,0.1
SLI_TOP,3
*NODE FILE
U, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*END STEP
**
** step 5: frequency extraction 
**
*STEP
*FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
28,,,1
*BOUNDARY
BC1,1
BOT,2,3
*BOUNDARY,BASE NAME=MOVA
 SLI_TOP,1,1
*BOUNDARY,BASE NAME=MOVB
 SLI_TOP,2,2
*BOUNDARY,BASE NAME=MOVC
 SLI_TOP,3,3
*CONTACT FILE,FREQ=0
*NODE FILE,F=0
*EL FILE,F=0
*MODAL FILE
*NODE PRINT,F=0
*EL PRINT,F=0
*END STEP
**
** step 6: Steady state dynamics, subspace projection
**
*STEP
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,INTERVAL=RANGE
20,100,5
*BASE MOTION,BASE NAME=MOVA,AMPLITUDE=CONSTA,DOF=1,TYPE=DISPLACEMENT
*BASE MOTION,BASE NAME=MOVB,AMPLITUDE=CONSTB,DOF=2,TYPE=DISPLACEMENT
*BASE MOTION,BASE NAME=MOVC,AMPLITUDE=CONSTC,DOF=3,TYPE=DISPLACEMENT
*NODE FILE
TU, 
RF, 
*EL FILE
E, 
S, 
*CONTACT FILE
*END STEP