*HEADING
: SIMPLE CONTACT, TUBE-TUBE INTERFACE WITH EXTERNAL CONTACT  [ITT31]
*NODE
1,0.,0.
5,10.,0.
11,0.,0.45
13,4.,0.45
*NGEN,NSET=OUTER_NODES
1,5
*NGEN,NSET=INNER_NODES
11,13
*ELEMENT,TYPE=B31
1,1,2
11,11,12
*ELGEN,ELSET=OUTER_ELEMENTS
1,4
*ELGEN,ELSET=INNER_ELEMENTS
11,2
*BEAM SECTION,SECT=PIPE,ELSET=OUTER_ELEMENTS,MATERIAL=STEEL
.25,.05
*BEAM SECTION,SECT=PIPE,ELSET=INNER_ELEMENTS,MATERIAL=STEEL
.18,.03
*ELSET,ELSET=BEAMS
INNER_ELEMENTS,OUTER_ELEMENTS
*MATERIAL,NAME=STEEL
*ELASTIC
30E6,.3
*ELEMENT,TYPE=ITT31,ELSET=INTERFACE_ELEMENTS
21,12
22,13
*INTERFACE,ELSET=INTERFACE_ELEMENTS
-.43, 
*SLIDE LINE,ELSET=INTERFACE_ELEMENTS,TYPE=LINEAR
1,2,3,4,5
*BOUNDARY
1,1,6
11,1,6
**
*STEP,NLGEOM,INC=20
Step 1 - MOVE NODE 5 IN +Y DIRECTION
*STATIC
0.5,1.
*CONTROLS,PARAMETERS=FIELD
1.0E-6, 
*BOUNDARY
5,2,2,2.0
*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,INC=20
Step 2 - MOVE NODE 5 IN +Z DIRECTION
*STATIC,RIKS
.07,1.,,,1.0
*BOUNDARY
5,3,3,2.0
*PRINT,CONTACT=YES
*MONITOR,NODE=5,DOF=3
*END STEP