*HEADING
          TWO DIMENSIONAL HEAT TRANSFER INTERFACE (CAX4RT)
          GAP RADIATION 
**
** The temperature at the NOUT nodes, based on a 1D model, is:
** NT_out=100+HFL2*R_th; R_th=L/(kA);  
** See ch. 1.7.1 of ABAQUS/Verification Manual   
**
*PHYSICAL CONSTANTS,ABS=-460.,STEFAN=5.E-10
*NODE,NSET=NALL
1,10.0,0.0
2,11.0,0.0
3,11.0,0.50
4,10.0, 0.50
7,11.0,1.0
8,10.0,1.
11,10.0,-.01
12,11.0,-.01
17,11.0,-1.0
18,10.0,-1.0
*NSET, NSET=SIDE3
7,8
*NSET,NSET=GAP1
11,12,17,18
*NSET,NSET=QA_TEST
1,2
*NSET,NSET=NOUT
QA_TEST,
*ELEMENT,TYPE=CAX4RT,ELSET=MID
1, 1,2,3,4
*ELEMENT, TYPE=CAX4RT,ELSET=TOP
2,4,3,7,8
*ELEMENT,TYPE=CAX4RT,ELSET=BOT
3,18,17,12,11
*ELSET,ELSET=TOP
1,2
*ELSET,ELSET=SOLID
1,2,3
*SOLID SECTION,ELSET=SOLID,MATERIAL=SOLMAT
*MATERIAL,NAME=SOLMAT
*CONDUCTIVITY
1., 
*SPECIFIC HEAT
46., 
*DENSITY
7850., 
*ELASTIC
1.0,0.0
*SURFACE,TYPE=ELEMENT, NAME=SURF3
MID,S1
*SURFACE,TYPE=ELEMENT, NAME=SURF4
BOT,S3
*STEP
*DYNAMIC TEMPERATURE-DISPLACEMENT, EXPLICIT
 ,1000000.
*CONTACT PAIR, INTERACTION=GAP,WEIGHT=1.0
SURF3,SURF4
*SURFACE INTERACTION, NAME=GAP
*GAP RADIATION
1.0,1.0
1.0,0.0
1.0,10.0
*BOUNDARY,OP=NEW
SIDE3,11,,100.
GAP1,11,,50.
******************************
*FILE OUTPUT, NUM=1
*NODE FILE,NSET=NOUT
 NT,
******************************
*OUTPUT,FIELD,NUM=1
*NODE OUTPUT,NSET=QA_TEST
NT
*NODE OUTPUT,NSET=NALL
NT
********************************
***OUTPUT, HISTORY,TIME INTERV=1E5
***NODE OUTPUT, NSET=NOUT
**NT, 
***ELEMENT OUTPUT, ELSET=TOP
**HFL2,
********
*OUTPUT, HISTORY,TIME INTERV=1.0E6
*ENERGY OUTPUT,VAR=ALL
*********
*END STEP