*HEADING
VERIFICATION OF ACOUSTIC/STRUCTURAL ANALYSIS - UNCOUPLED CASE 
*NODE,NSET=QA_TEST
10, 0.0
20, 5.0
*ELEMENT,TYPE=AC1D2,ELSET=FLUID
1, 10,20
*ELEMENT,TYPE=MASS,ELSET=MASS
2, 20
*ELEMENT,TYPE=SPRING1,ELSET=SPRING
3, 20
*ELEMENT,TYPE=DASHPOT1,ELSET=DASHPOT
4, 20
*SOLID SECTION,MATERIAL=FLUID,ELSET=FLUID
*MATERIAL,NAME=FLUID
*DENSITY
0.4008, 
*ACOUSTIC MEDIUM,BULK MODULUS
10., 
*ACOUSTIC MEDIUM,VOLUMETRIC DRAG
0.04, 
*MASS,ELSET=MASS
4., 
*SPRING,ELSET=SPRING
1, 
1.0, 
*DASHPOT,ELSET=DASHPOT
1, 
0.08, 
*IMPEDANCE PROPERTY,NAME=RAS
0.25,0.01
*BOUNDARY
10, 8,
20, 2, 3
******************
*STEP
STEP 1: REAL EIGENVALUES
*FREQUENCY, eigensolver=lanczos, SIM=NO
2, , 
*EL PRINT,SUMMARY=NO
S,E
*NODE FILE
U, 
*END STEP
************************************************
*STEP
STEP 2: SUBSPACE PROJECTION
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,INTERVAL=RANGE, FREQUENCY SCALE=LINEAR
0.01,.3,30,0.
*IMPEDANCE,PROPERTY=RAS
1,I2,
*CLOAD
20,1, 1.0
20,8, 1.0
*NODE PRINT,SUMMARY=NO
U1,POR,PU1,PPOR
*EL PRINT,FREQUENCY=999,ELSET=SPRING
S,E
*NODE FILE
U,POR,PU,PPOR
*OUTPUT,FIELD,OP=NEW
*NODE OUTPUT
U,POR,
*OUTPUT,HISTORY,OP=NEW
*NODE OUTPUT,NSET=QA_TEST
U,POR,
*END STEP
******************
*STEP
STEP 3: DIRECT
*STEADY STATE DYNAMICS, DIRECT,FREQUENCY SCALE=LINEAR
0.01,.3,30,0.
*IMPEDANCE,PROPERTY=RAS
1,I2,
*CLOAD
20,1, 1.0
20,8, 1.0
*NODE PRINT,SUMMARY=NO
U1,POR,PU1,PPOR
*EL PRINT,FREQUENCY=999,ELSET=SPRING
S,E
*NODE FILE
U,POR,PU,PPOR
*OUTPUT,FIELD,OP=NEW
*NODE OUTPUT
U,POR,
*OUTPUT,HISTORY,OP=NEW
*NODE OUTPUT,NSET=QA_TEST
U,POR,
*END STEP