*HEADING
 : CONTACT TEST, RING SLIDING ON CYLINDER [ISL21A with CAX4]
 KEYWORD-PARAMETER COMBINATION TESTED: TORQUE PRINT, FREQ
 Liner Perturbation steps with Load Case Definition
*RESTART,WRITE,FREQ=99
*NODE,NSET=NFILE
 1, 1.3,7.
 36, 1.3,0.
 301, 1.6,7.
 336, 1.6,0.
 401, 1.6,8.
 416, 1.6,6.
 601, 1.8,8.
 616, 1.8,6.
 701, 1.8,7.
 704, 1.8,6.4
 1001, 2.1,7.
 1004, 2.1,6.4
*NGEN,NSET=BASE
 36,336,100
*NGEN,NSET=TOP
 1,301,100
*NGEN,NSET=B1
 401,601,100
*NGEN,NSET=B2
 416,616,100
*NGEN,NSET=C1
 701,1001,100
*NGEN,NSET=C2
 704,1004,100
*NFILL
 TOP,BASE,35
 B1,B2,15
 C1,C2,3
*ELEMENT,TYPE=CAX4
 1, 2,102,101,1
 501, 402,502,501,401
 801, 702,802,801,701
*ELGEN,ELSET=STEEL
 1, 3,100,1, 35,1,10
 501, 2,100,1, 15,1,10
 801, 3,100,1, 3,1,10
*ELSET,ELSET=OUTER
 803,813,823
*ELEMENT,TYPE=ISL21A
 401, 401,402
 701, 701,702
*ELGEN,ELSET=SLIDE1
 401,15,1,1
*ELGEN,ELSET=SLIDE2
 701,3,1,1
*INTERFACE,ELSET=SLIDE1
*FRICTION
 .2, 
*INTERFACE,ELSET=SLIDE2
*FRICTION
 .6, 
*SOLID SECTION,ELSET=STEEL,MATERIAL=STEEL
*MATERIAL,NAME=STEEL
*ELASTIC
 30.E6,0.3
*SLIDE LINE,TYPE=LINEAR,ELSET=SLIDE1,GENERATE
 301,331,1
*SLIDE LINE,TYPE=LINEAR,ELSET=SLIDE2,GENERATE
 601,616,1
**********
*ELSET,ELSET=EFILE
SLIDE1,SLIDE2
*STEP,NLGEOM
  PRESSURIZE COLLAR
*STATIC
 1.0,1.0
*BOUNDARY
 BASE,2
 TOP,2
 336,1
 1001,2
 601,2
*DLOAD
 OUTER,P2,30000.
*PRINT,CONTACT=YES
*NODE PRINT,FREQ=2
U,RF
*EL PRINT,ELSET=SLIDE1
S,E
*EL PRINT,ELSET=SLIDE2
S,E
*EL PRINT,ELSET=STEEL,FREQ=99
S,E
SINV, 
*EL FILE,ELSET=EFILE,FREQ=99
S,E
*NODE FILE,NSET=NFILE,FREQ=99
U,RF
*TORQUE PRINT, FREQ=99
*END STEP
*STEP,NLGEOM
  MOVE SLIDER DOWN
*STATIC
 .1,1.0
*BOUNDARY
 BASE,2
 TOP,2
 336,1
 1001,2,,-4.5
 601,2,,-5.
*END STEP

*STEP,PERTURBATION
*STATIC
*LOAD CASE,NAME="Slider Down-1"
*BOUNDARY
 BASE,2
 TOP,2
 336,1
 1001,2,,-2.25
 601,2,,-2.5
*END LOAD CASE
*LOAD CASE,NAME="Slider Down-2"
*BOUNDARY
 BASE,2
 TOP,2
 336,1
 1001,2,,-4.5
 601,2,,-5
*END LOAD CASE
*OUTPUT,FIELD,FREQ=99
*NODE OUTPUT,NSET=NFILE
U,RF
*END STEP