*HEADING
** 
*PREPRINT, ECHO=NO, MODEL=NO, HISTORY=YES
*NODE,NSET=BEAMS,SYSTEM=C
      25001,4.0,90.0,0.0
      25071,4.0,-90.0,0.0
********************************
*NODE,NSET=STIFFNER
55,0.0,-2.0
65,1.0,-2.0
75,3.0,-1.1
*****
*NGEN,NSET=BEAMS,LINE=C
 25001,25071,1,,0,0,0,0,0,-1
*NSET,NSET=OUT
 25001, 25071, 25036,75
*NSET,NSET=P_OUT
1,21,41,1001,1021,1041 
****************************
*NODE,NSET=INNER,SYSTEM=C
1,4.0,90.0,0.0
41,4.0,-90.0,0.0
*NGEN,NSET=INNER,LINE=C
1,41,1,,0,0,0,0,0,-1
*****************************
*NODE,NSET=OUTER,SYSTEM=C
2001,8.0,90.0,0.0
2041,8.0,-90.0,0.0
*NGEN,NSET=OUTER,LINE=C
2001,2041,1,,0,0,0,0,0,-1
*****************************
*NFILL,NSET=ACOUSTIC
INNER,OUTER,20,100
**********************************
*ELEMENT,TYPE=SAX1,ELSET=BEAMS
2001, 25001,25002
*ELGEN,ELSET=BEAMS
2001,70,1,1
*ELEMENT,TYPE=SAX1,ELSET=STIFFNER
3001,55,65
4001,65,25060
5001,75,25048
6001,75,25040
******************
*ELEMENT, TYPE=ACAX4,ELSET=ACOUSTIC
1,1,2,102,101
*ELGEN, ELSET=ACOUSTIC
1,40,1,1,20,100,40
****************************
*ELGEN,ELSET=SLAVE
1,40,1,1
*SURFACE,TYPE=ELEMENT,NAME=SLAVE
SLAVE,S1
*SURFACE,TYPE=ELEMENT,NAME=MASTER
BEAMS,SPOS
*TIE,NAME=COUPLING,adjust=no,position tolerance=1.0
SLAVE,MASTER
************************************
*MATERIAL,NAME=WATER
*DENSITY
1000.0, 
*ACOUSTIC MEDIUM,BULK MODULUS
2.25E9,
*SOLID SECTION,MATERIAL=WATER,ELSET=ACOUSTIC
0.1,
*******************
*SHELL SECTION,MATERIAL=MAT1,ELSET=BEAMS
0.1,
*SHELL SECTION,MATERIAL=MAT1,ELSET=STIFFNER
0.1,
*MATERIAL,NAME=MAT1
*ELASTIC
207E9,0.3
*DENSITY
7800
*************************
*ELSET,ELSET=OUTER,GENERATE
761,800,1
*SURFACE,NAME=OUTER
OUTER,S3
**********************
*STEP,INC=1000
*STEADY STATE DYNAMIC,DIRECT
1.0,40.0,2,1
*IMPEDANCE,NONREFLECTING=SPHER
OUTER,I3,8.0
*CLOAD
55,2,100.0
*BOUNDARY
25001,1,1,0.0
25071,1,1,0.0
25001,6,6,0.0
25071,6,6,0.0
55,1,1,0.0
55,6,6,0.0
*ENERGYPRINT
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=BEAMS
U
*NODE OUTPUT,NSET=ACOUSTIC
POR,
*ELEMENTOUTPUT,ELSET=ACOUSTIC
ENER,ELEN,INTEN
*OUTPUT,HISTORY,FREQ=1
*NODE OUTPUT,NSET=BEAMS
U,V,A
*NODE OUTPUT,NSET=P_out
POR,
*END STEP
************************
*STEP,INC=1000
*STEADY STATE DYNAMIC,DIRECT
1.0,40.0,2,1
*IMPEDANCE,NONREFLECTING=SPHER,OP=NEW
*SIMPEDANCE,NONREFLECTING=SPHER
OUTER,8.0
*CLOAD
55,2,100.0
*ENERGYPRINT
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=BEAMS
U
*NODE OUTPUT,NSET=ACOUSTIC
POR,
*ELEMENTOUTPUT,ELSET=ACOUSTIC
ENER,ELEN,INTEN
*OUTPUT,HISTORY,FREQ=1
*NODE OUTPUT,NSET=BEAMS
U,V,A
*END STEP

****************************
*STEP,INC=1000
*Frequency, eigensolver=Lanczos, acoustic coupling=on, normalization=MASS
100, , 3000., -1.0, , 
*IMPEDANCE,NONREFLECTING=SPHER,OP=NEW
*SIMPEDANCE,NONREFLECTING=SPHER,OP=NEW
OUTER,8.0
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=BEAMS
U
*NODE OUTPUT,NSET=ACOUSTIC
POR,
*END STEP
************************