*HEADING
: *CONTACT INTERFERENCE,TYPE=ELEMENT SIMPLE ALLOW. INTERFER.  [ITT21]
*NODE
1,
2,1.,
3,2.,1.2,
4,3.,1.4
11,-1.,1.
12,1.,1.
13,2.,1.
14,4.,1.
*ELEMENT,TYPE=B21,ELSET=INT
1,1,2
2,2,3
3,3,4
*ELEMENT,TYPE=B21,ELSET=OUT
11,11,12
12,12,13
13,13,14
*BEAM SECTION,SECTION=RECT,ELSET=INT,MATERIAL=MAT
1.,2.
*BEAM SECTION,SECTION=RECT,ELSET=OUT,MATERIAL=MAT
1.,2.
*MATERIAL,NAME=MAT
*ELASTIC
1.E5,0.
*BOUNDARY
4,1,6
11,1,6
12,1,6
13,1,6
14,1,6
*ELEMENT,TYPE=ITT21,ELSET=INTER
21,4
22,3
23,2
24,1
*INTERFACE,ELSET=INTER
0.5, 
*SLIDELINE,ELSET=INTER,TYPE=LINEAR
11,12,13,14
*STEP,INC=20,NLGEOM
*STATIC
0.2,1.,0.2,0.2
*CONTACT INTERFERENCE,TYPE=ELEMENT
INTER,0.5
*EL FILE
S, 
*OUTPUT,FIELD
*ELEMENT OUTPUT
S,
*NODE FILE
U, 
*OUTPUT,FIELD
*NODE OUTPUT
U,
*PRINT,CONTACT=YES
*ENDSTEP