*HEADING
 Elastic body problem, S4R
 The "structure" alone has a frequency of 1.0 Hz
**
*NODE, NSET=PLATE
 100, 0.0, 0.0, 0.0
 200, 1.5, 0.0, 0.0
 300, 1.5, 1.5, 0.0
 400, 0.0, 1.5, 0.0
*NODE, NSET=FLUID_B
  1, 0.0, 0.0, 0.0
  2, 1.5, 0.0, 0.0
  3, 1.5, 1.5, 0.0
  4, 0.0, 1.5, 0.0
*NODE, NSET=FLUID_F
  5, 0.0, 0.0, 0.01
  6, 1.5, 0.0, 0.01
  7, 1.5, 1.5, 0.01
  8, 0.0, 1.5, 0.01
*NSET, NSET=ANODE
 200, 
**
*ELEMENT, TYPE=S4R, ELSET=PLATE
 101,  100, 200, 300, 400
*ELEMENT,TYPE=AC3D8, ELSET=FLUID
 1, 1,2,3,4, 5,6,7,8
*SHELL SECTION, ELSET=PLATE, MATERIAL=STEEL
 1, 
*MATERIAL, NAME=STEEL
*ELASTIC
 30.0E6, 0.3
*DENSITY
 5.3E-4, 
*SOLID SECTION, ELSET=FLUID, MATERIAL=FLUID
*MATERIAL, NAME=FLUID
*ACOUSTIC MEDIUM
 549.69
*DENSITY
 9.3E-5
**
*SURFACE,NAME=SOLID
 101,SPOS
*SURFACE,NAME=FLUID
 1,S1
*SURFACE,NAME=PLANE
 1,S2
*TIE,NAME=COUPLE,ADJUST=NO
 FLUID,SOLID
**
*BOUNDARY
 PLATE, 1,2
 PLATE, 4,6
**
*INCIDENT WAVE PROPERTY,NAME=USA,TYPE=PLANE
 .75,.75,0.,
 .75,.75,1.E2
*INCIDENT WAVE FLUID PROPERTY
 549.69,9.3E-5
**
*AMPLITUDE,NAME=PRES,DEFINITION=EQUALLY SPACED,FIXED INTERVAL=50.0,SMOOTH=0.0,
TIME=TOTAL TIME
 1.0, 1.0
**
** Step 1
**
*STEP, INC=1000
*DYNAMIC, ALPHA=0.0
 2.50E-6, 2.5E-4
*INCIDENT WAVE, PRESSUREAMPLITUDE=PRES,PROPERTY=USA
 SOLID,1.0
*INCIDENT WAVE, PRESSUREAMPLITUDE=PRES,PROPERTY=USA
 FLUID,1.0
*SIMPEDANCE
 PLANE,
**
***NODE FILE, NSET=ANODE, FREQUENCY=1
** V,
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=FLUID_F
 POR,
*NODE OUTPUT,NSET=ANODE
 U,V,
*OUTPUT,HISTORY,FREQ=1
*NODE OUTPUT,NSET=FLUID_F
 POR
*NODE OUTPUT,NSET=PLATE
 RF
*NODE OUTPUT,NSET=ANODE
 U,V,
*END STEP