*HEADING
 Tube with nonreflective end condtion and *TIE constraint.
 Part of the air in the tube is modelled with continuum elements
 with air properties.
********************
*preprint,history=yes,model=yes
*NODE, Nset=ODB_NSET
1,000.0,0.0
21,000.5,0.0
101,000.0,0.025
121,000.5,0.025
*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=AC2D4
1,1,2,102,101
*ELGEN,ELSET=ACOU
1,5,1,1
** Then 5 continuum elements
*ELEMENT,TYPE=CPS4R
6,10006,10007,10107,10106
*ELGEN,ELSET=STRUCT
6,5,1,1
** Next 10 elements are acoustic
*ELEMENT,TYPE=AC2D4
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
SOR,ACL
************************************************
**
**  Acoustic Element Properties
**
*SOLID SECTION,MATERIAL=AIR,ELSET=ACOU
40.,
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 142400.,
************************************************
**
**  Continuum Element Properties
**
*SOLID SECTION,MATERIAL=AIRSOLID,ELSET=STRUCT
40.,
*MATERIAL,NAME=AIRSOLID
*DENSITY
 1.21,
*ELASTIC
 142400.,
************************************************  
*Elset,Elset=ODB_ESET
ACOU, STRUCT
*Nset, Nset=ODB_NSET
ODB_NSET, NALL, SAMPLE, LOAD
*nset,nset=struct_sample
10006,10107
************************************************  
*STEP
*FREQUENCY,norm=mass
44,,,10000
*OUTPUT,FIELD,FREQ=0
*END STEP
**------------------------------------------------
*STEP,inc=10000
*MODAL DYNAMIC
0.00001,.005
*CLOAD
LOAD, 8,314.1592654
** simulation of uniaxial condition
*OUTPUT,FIELD,FREQ=1000
*ELEMENT OUTPUT,ELSET=STRUCT
S
*NODE OUTPUT,NSET=SAMPLE
POR,
*OUTPUT,HISTORY,FREQUENCY=1
*NODE OUTPUT,NSET=SAMPLE
POR,
*NODE OUTPUT,NSET=struct_sample
u,
*END STEP
**------------------------------------------------
*STEP,inc=10000
*DYNAMIC
0.00001,.005
*CLOAD
LOAD, 8,314.1592654
** simulation of uniaxial condition
*OUTPUT,FIELD,FREQ=1000
*ELEMENT OUTPUT,ELSET=STRUCT
S
*NODE OUTPUT,NSET=SAMPLE
POR,
*OUTPUT,HISTORY,FREQUENCY=1
*NODE OUTPUT,NSET=SAMPLE
POR,
*NODE OUTPUT,NSET=struct_sample
u,
*END STEP