*HEADING
SIMPLE  TESTS, FINITE SLIDING, CGAX8                          :--  
*RESTART,WRITE, FREQ=100
*NODE
1,1.,5.
2,1.5,5.
3,2.,5.
4,1.,7.5
5,2.,7.5
6,1.,10
7,1.5,10.
8,2.,10.
10,1.9,3.0
11,2.4,3.0
12,2.9,3.0
22,1.9,12.0
23,2.4,12.0
24,2.9,12.0
*NGEN
10,22,3
11,23,3
12,24,3
*ELEMENT,TYPE=CGAX8,ELSET=LEFTEL
1,1,3,8,6,2,5,7,4
*ELEMENT,TYPE=CGAX8,ELSET=RTEL
3,10,12,18,16,11,15,17,13
4,16,18,24,22,17,21,23,19
*ELSET,ELSET=SOLID
LEFTEL, RTEL
*NSET, NSET=LT_N
1, 
*NSET, NSET=RT_N
12, 
*NSET, NSET=MAS_N
10,13,16,19,22
*MPC
TIE,6,4
TIE,4,1
TIE,24,21
TIE,21,18
TIE,18,15
TIE,15,12
*TRANSFORM, NSET=MAS_N
1.,1.,0.,-1.,1.,0.
*SOLID SECTION,ELSET=SOLID,MATERIAL=SOLMAT
*MATERIAL,NAME=SOLMAT
*ELASTIC
30.E6,0.30
*SURFACE INTERACTION,NAME=SLIDE
 1., 
*FRICTION, ANISOTROPIC
0.1,0.2
*surface,NAME=LEFT
LEFTEL,S2
*surface,NAME=RT
RTEL,S4
*CONTACT PAIR,INTERACTION=SLIDE
LEFT,RT
*BOUNDARY
LT_N,1,2
LT_N,5,5
RT_N,1,2
RT_N,5,5
**
**    step 1  :  interference fit, (radial intereference)
**
*STEP, INC=20, NLGEOM
           SHRINK FIT
*STATIC 
0.1,1.,0.1,0.2
*CONTACT INTERFERENCE,SHRINK
LEFT, RT
*NODE PRINT, F=100, GLO=YES
U, 
*EL PRINT, F=0
*OUTPUT,FIELD,FREQ=0
*ELEMENT OUTPUT
*OUTPUT,FIELD,FREQ=100
*NODE OUTPUT
U,
*OUTPUT,FIELD,FREQ=50
*CONTACT OUTPUT,VARIABLE=PRESELECT,SLAVE=LEFT,MASTER=RT
*CONTACT PRINT, SLAVE=LEFT , MASTER=RT, F=50
*ENDSTEP
**
**     step 2 : linear perturbation (about shrink fit); sliding upwards
**
*STEP,PERT,  NLGEOM
 PERT :- SLIDING UPWARDS
*STATIC
*BOUNDARY, OP=MOD
RT_N,2,,0.1
*NODE PRINT, F=100,GLO=YES
U, 
*EL PRINT, F=0
*OUTPUT,FIELD,FREQ=0
*ELEMENT OUTPUT
*OUTPUT,FIELD,FREQ=100
*NODE OUTPUT
U,
*OUTPUT,FIELD,FREQ=50
*CONTACT OUTPUT,VARIABLE=PRESELECT,SLAVE=LEFT,MASTER=RT
*CONTACT PRINT, SLAVE=LEFT , MASTER=RT, F=50
*ENDSTEP
**
**     step 3 : linear perturbation (about shrink fit); twist 
**
*STEP, PERT, NLGEOM
  PERT: TWISTING
*STATIC
*BOUNDARY, OP=MOD
RT_N,5,,0.1
*OUTPUT,FIELD,FREQ=50
*CONTACT OUTPUT,VARIABLE=PRESELECT,SLAVE=LEFT,MASTER=RT
*CONTACT PRINT, SLAVE=LEFT , MASTER=RT, F=50
*ENDSTEP
**
**     step 4: UNSYMM, linear perturbation, slide and twist
** 	          with shrink-fit base state.
**
*STEP,  PERT, NLGEOM, UNSYMM=YES
*STATIC
*BOUNDARY
RT_N,5,,0.1
RT_N,2,,0.1
*OUTPUT,FIELD,FREQ=50
*CONTACT OUTPUT,VARIABLE=PRESELECT,SLAVE=LEFT,MASTER=RT
*CONTACT PRINT, SLAVE=LEFT , MASTER=RT, F=50
*ENDSTEP
**
**       step 5: NLGEOM, UNSYMM, twist and sliding
**
*STEP, NLGEOM, UNSYMM=YES
*STATIC
0.1,1.0
*CONTROLS,PARAMETERS=FIELD
1.0E-6, 
*BOUNDARY
RT_N,2,,0.1
RT_N,5,,0.1
*NODE PRINT, F=100, GLO=YES
U, 
*OUTPUT,FIELD,FREQ=100
*NODE OUTPUT
U,
*ENDSTEP