*HEADING
 Acoustic test - 1D Problem, SS-DIRECT.
 A 4m long tube; from left to right,
 a sound source, 3m is air, then 1m of a highly
 absorbent material, followed by a rigid
 termination. 
*PREPRINT,ECHO=NO,HISTORY=NO,MODEL=NO
*RESTART,WRITE
***********************************************************
**
**
**   Mesh Generation
**
*NODE, Nset=ODB_NSET
    1,0,
  401,4,
*NGEN,NSET=ALL
   1,401
*NSET,NSET=QA_TEST,GENERATE
 1,401,10
*NSET,NSET=LOAD
 1,
*ELEMENT,TYPE=AC1D2
 1,1,2
*ELGEN,ELSET=CHANNEL
 1,300
*ELEMENT,TYPE=AC1D2
  301,301,302,
*ELGEN,ELSET=ABSORB
  301,100
**
**
************************************************
**    ** ELEMENT PROPERTIES **
**
*SOLID SECTION,MATERIAL=AIR,ELSET=CHANNEL
*SOLID SECTION,MATERIAL=ABSORB,ELSET=ABSORB
**
**
*MATERIAL,NAME=AIR
*DENSITY
 1.19,20.0
 1.21,40.0
 1.19,50.0
 1.17,60.0
 1.15,80.0
 1.13,100.0
 1.11,120.0
 1.09,140.0
 1.07,160.0
 1.05,180.0
 1.03,200.0
 1.01,240.0
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1420e6,20.0
 0.1424E6,40.0
 0.1445E6,80.0
 0.1509E6,120.0
 0.1556E6,160.0
 0.1466E6,200.0
 0.9710E5,240.0
**
**
*MATERIAL,NAME=ABSORB
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
*ACOUSTIC MEDIUM,VOLUMETRIC DRAG
 1e4,
*INITIAL CONDITIONS,TYPE=TEMPERATURE
ALL,40.0
**
**
**
*************************************************
**
*Elset,Elset=ODB_ESET
CHANNEL, ABSORB
**
**
*Nset, Nset=ODB_NSET
ODB_NSET, ALL, QA_TEST
**
**
*STEP
*STEADY STATE DYNAMICS,DIRECT,FREQUENCY SCALE=LINEAR
 100,1100,3,1
**
** Prescribe outward acceleration of 100 at loaded nodes.
** The tributary area of each node is 1/100, so the
** outward volume acceleration is 1.
*CLOAD
 LOAD,8, -1e2
**
*NODE PRINT, NSET=QA_TEST
 POR,PPOR,
*EL PRINT,FREQUENCY=0
*ENERGYPRINT
*OUTPUT,FIELD
*NODE OUTPUT,NSET=QA_TEST
 POR,
*ELEMENT OUTPUT
ACV,INTEN,GRADP,ENER,ELEN,ELEDEN
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
 POR,
*ENERGY OUTPUT
ALLSE,ALLKE,ALLWK,ALLVD
*ENDSTEP
**
**
*STEP
*FREQUENCY,NORM=MASS,EIGENSOLVER=LANCZOS, SIM=NO
50, , ,
*NODE PRINT,F=0
*EL PRINT,F=0
*OUTPUT,FIELD,Frequency=0
*END STEP
**
**
*STEP
*STEADY STATE DYNAMICS,SUBSPACE PROJECTION,FREQUENCY SCALE=LINEAR,INTERVAL=RANGE
 100,1100,3,1
**
** Prescribe outward acceleration of 100 at loaded nodes.
** The tributary area of each node is 1/100, so the
** outward volume acceleration is 1.
*CLOAD
 LOAD,8, -1e2
**
*NODE PRINT, NSET=QA_TEST
 POR,PPOR,
*EL PRINT,FREQUENCY=0
*energyprint
*OUTPUT,FIELD,VARIABLE=PRESELECT,OP=ADD,FREQUENCY=9999
*OUTPUT,FIELD, OP=ADD
*NODE OUTPUT,NSET=QA_TEST
 POR,
*ELEMENT OUTPUT,ELSET=ABSORB
ACV,INTEN,GRADP
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=QA_TEST
 POR,
*ENERGY OUTPUT
ALLSE,ALLKE,ALLWK,ALLVD
*ENDSTEP