*HEADING
 Elastic body problem, C3D8R
 The "structure" alone has a frequency of 1.0 Hz
*NODE, NSET=BACK_S
 1,  0.0, 0.0, 1.0
 3,  0.0, 0.0, 0.0
 5,  0.0, 1.0, 1.0
 7,  0.0, 1.0, 0.0
*NODE, NSET=FRONT_S
 2, 10.0, 0.0, 1.0
 4, 10.0, 0.0, 0.0
 6, 10.0, 1.0, 1.0
 8, 10.0, 1.0, 0.0
*NODE, NSET=BACK_F
 22, 10.0, 0.0, 1.0
 24, 10.0, 0.0, 0.0
 26, 10.0, 1.0, 1.0
 28, 10.0, 1.0, 0.0
*NODE, NSET=FRONT_F
 12, 10.01, 0.0, 1.0
 14, 10.01, 0.0, 0.0
 16, 10.01, 1.0, 1.0
 18, 10.01, 1.0, 0.0
*NSET, NSET=NODE2
 2,
**
*ELEMENT, TYPE=C3D8R, ELSET=SOLID
 1, 1,2,4,3, 5,6,8,7
*ELEMENT,TYPE=AC3D8, ELSET=FLUID
 2, 22,12,14,24, 26,16,18,28
*SOLID SECTION, ELSET=SOLID, MATERIAL=ELAS
*MATERIAL, NAME=ELAS
*ELASTIC
 1973.9209,
*DENSITY
 1.0,
**
*SOLID SECTION, ELSET=FLUID, MATERIAL=FLUID
*MATERIAL, NAME=FLUID
*ACOUSTIC MEDIUM
 1.0
*DENSITY
 1.0
**
*SURFACE,NAME=SOLID
 1,S4
*SURFACE,NAME=FLUID
 2,S6
*SURFACE,NAME=PLANE
 2,S4
**
*TIE,NAME=COUPLE
 FLUID,SOLID
**
*BOUNDARY
 BACK_S,  1,3
 FRONT_S, 2,3
**
*INCIDENT WAVE PROPERTY,NAME=USA,TYPE=PLANE
 10.,0.,0.,
 100.,0.,0.
*INCIDENT WAVE FLUID PROPERTY
 1.0,1.0
*AMPLITUDE,NAME=PRES,DEFINITION=EQUALLY SPACED,FIXED INTERVAL=50.0,
 SMOOTH=0.0,TIME=TOTAL TIME
 1.0, 1.0
**
** Step 1
**
*STEP, INC=400
*DYNAMIC, ALPHA=0.0
 0.025, 10.0
*INCIDENT WAVE, PRESSUREAMPLITUDE=PRES,PROPERTY=USA
 SOLID,1.0
*INCIDENT WAVE, PRESSUREAMPLITUDE=PRES,PROPERTY=USA
 FLUID,1.0
*SIMPEDANCE
 PLANE,
**
***NODE FILE, NSET=NODE2, FREQUENCY=1
** V,
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=FRONT_F
 POR,
*NODE OUTPUT,NSET=NODE2
 U,V,
*OUTPUT,HISTORY,FREQ=1
*NODE OUTPUT,NSET=FRONT_F
 POR,
*NODE OUTPUT,NSET=NODE2
 U,V,
*END STEP