*HEADING
 ECA44AFAT: ACAX4R AND CAX4R ELEMENTS
 Tube with nonreflective end condtion and *TIE constraint.
 Part of the air in the tube is modelled with continuum elements
 with air properties.
********************
*NODE, Nset=ODB_NSET
1,1000.0,0.0
21,1000.5,0.0
101,1000.0,0.025
121,1000.5,0.025
*NGEN,NSET=NALL
1,21
101,121
*NCOPY,OLDSET=NALL,NEWSET=NSOL,CHANGENUMBER=10000,SHIFT
0.0,0.0,0.0
1.0,0.0,0.0,0.0,1.0,0.0
*NSET,NSET=SAMPLE,GENERATE
1,41
*NSET,NSET=LOAD
1,101
** First 5 elements are acoustic
*ELEMENT,TYPE=ACAX4R
1,1,2,102,101
*ELGEN,ELSET=ACOU
1,5,1,1
** Then 5 continuum elements
*ELEMENT,TYPE=CAX4R
6,10006,10007,10107,10106
*ELGEN,ELSET=STRUCT
6,5,1,1
** Next 10 elements are acoustic
*ELEMENT,TYPE=ACAX4R
11,11,12,112,111
*ELGEN,ELSET=ACOU
11,10,1,1
*ELSET,ELSET=NONREF
20,
************************************************
*SURFACE,TYPE=ELEMENT,NAME=ACR
5,S2
*SURFACE,TYPE=ELEMENT,NAME=SOL
6,S4
*SURFACE,TYPE=ELEMENT,NAME=SOR
10,S2
*SURFACE,TYPE=ELEMENT,NAME=ACL
11,S4
*TIE,NAME=CRAVAT
SOL,ACR
ACL,SOR
************************************************
**
**  Acoustic Element Properties
**
*SOLID SECTION,MATERIAL=AIR,ELSET=ACOU
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
************************************************
**
**  Continuum Element Properties
**
*SOLID SECTION,MATERIAL=AIRSOLID,ELSET=STRUCT
*MATERIAL,NAME=AIRSOLID
*DENSITY
 1.21,
*ELASTIC
 0.1424E6,
*Elset,Elset=ODB_ESET
ACOU, STRUCT
*Nset, Nset=ODB_NSET
ODB_NSET, NALL, SAMPLE, LOAD
************************************************
*STEP
*DYNAMIC,EXPLICIT,ELEMENT BY ELEMENT
,.01 
*IMPEDANCE
 NONREF,I2
**
** Conditions at x=0 : Define the source inward accel
** to be  a =  omega i, so v (inward) = 1.
** The loaded node has a tributary area of 1.
**
*CLOAD
LOAD, 8, 78.539816E+5
** simulation of uniaxial condition
*BOUNDARY
NSOL,2,2
*OUTPUT,FIELD,NUMBER=5
*NODE OUTPUT,NSET=SAMPLE
POR,
**OUTPUT,HISTORY,FREQUENCY=1
**NODE OUTPUT,NSET=SAMPLE
**POR,
***ELEMENT OUTPUT,ELSET=STRUCT
**S11,
*END STEP