*HEADING
: ACOUSTIC-STRUCTURAL INTERFACE, 1st-ORDER  [ASI2]
*NODE,NSET=BASE
1, 
41,20.
*NODE,NSET=FSURF
11,0.,100.
51,20.,100.
*NFILL,NSET=FLUID
BASE,FSURF,10,1
*ELEMENT,TYPE=AC2D4
1,1,41,43,3
*ELGEN,ELSET=FLUID
1,5,2,1
*SOLID SECTION,ELSET=FLUID,MATERIAL=WATER
20., 
*ELEMENT,TYPE=ASI2,ELSET=INTER
6,1,41
*INTERFACE,ELSET=INTER
20., 
*MATERIAL,NAME=WATER
*ACOUSTIC MEDIUM,BULK MODULUS
2.0E9, 
*DENSITY
1000., 
*BOUNDARY
FSURF,8
*AMPLITUDE,DEFINITION=PERIODIC,NAME=SINE
1,10.,0.
0.,1.
*STEP,INC=200
*DYNAMIC,DIRECT
.02,1.
*BOUNDARY,AMP=SINE,TYPE=ACCELERATION
BASE,2,2,1.
*EL PRINT,FREQ=0
*NODE PRINT,FREQ=10
POR,A
*OUTPUT, FIELD, FREQ=25
*NODE OUTPUT
POR,A
*END STEP