*HEADING
: MODEL CHANGE ACOUSTICS TESTS  [AC2D4]
*PREPRINT,ECHO=YES,MODEL=YES,HISTORY=YES
*NODE, Nset=ODB_NSET
1, 
41,,10.
1001,.5
1041,.5,10.
2001,0.5,0.1
2041,0.5,10.1
3001,1.0,0.1
3041,1.0,10.1
*NGEN,NSET=NALL
1,41
1001,1041
2001,2041
3001,3041
*ELEMENT,TYPE=AC2D4,ELSET=EALL
1,1,1001,1003,3
*ELGEN,ELSET=EALL
1,20,2,1
*ELSET,ELSET=SECOND
16,17,18,19,20
*MATERIAL,NAME=AIR
*DENSITY
1.293, 
*ACOUSTIC MEDIUM,BULK MODULUS
1.42176E5, 
*SOLID SECTION,MATERIAL=AIR,ELSET=EALL
*NSET,NSET=RECRD,GEN
1,21
*NSET,NSET=DRIV
1,1001
**************************************
*Elset,Elset=ODB_ESET
SECOND, EALL
**
**
*Nset, Nset=ODB_NSET
ODB_NSET, NALL, RECRD, DRIV
**
**
*STEP
*STEADY STATE DYNAMIC,DIRECT
1., 
*IMPEDANCE
20,I3,
*BOUNDARY
DRIV,8,,1.
*NODE PRINT,NSET=RECRD
POR,PPOR
*NODE FILE,NSET=RECRD
POR,PPOR
*OUTPUT,FIELD,VARIABLE=PRESELECT,OP=ADD,FREQUENCY=9999
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT,NSET=RECRD
POR,
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT,NSET=RECRD
POR,
*ENDSTEP
**************************************
*STEP
*STATIC
1,1
*MODEL CHANGE,REMOVE
SECOND,
*ENDSTEP
**************************************
*STEP
*STEADY STATE DYNAMIC,DIRECT
1., 
*IMPEDANCE,OP=NEW
15,I3,
*BOUNDARY
DRIV,8,,1.
*NODE PRINT,NSET=RECRD
POR,PPOR
*NODE FILE,NSET=RECRD
POR,PPOR
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT,NSET=RECRD
POR,
*OUTPUT,HISTORY,OP=ADD
*NODE OUTPUT,NSET=RECRD
POR,
*ENDSTEP