*HEADING
UNDEX Benchmark Problem
Fluid Coupled Concentric Cylinders, Inner Cylinder Air Backed
**
** Shell Nodes
**
*NODE,NSET=PLANE
    1,  0.8,0.0,0.0
   19, -0.8,0.0,0.0
   21,  0.8,0.0,0.175
   39, -0.8,0.0,0.175
   41,  1.0,0.0,0.0
   59, -1.0,0.0,0.0
   61,  1.0,0.0,0.175
   79, -1.0,0.0,0.175
*NODE
 99998,  0.0,0.0,0.0
 99999,  0.0,0.0,0.175
*NGEN,NSET=IB,LINE=C
 1,19,1,99998,,,,0,0,1
*NGEN,NSET=IF,LINE=C
 21,39,1,99999,,,,0,0,1
*NGEN,NSET=OB,LINE=C
 41,59,1,99998,,,,0,0,1
*NGEN,NSET=OF,LINE=C
 61,79,1,99999,,,,0,0,1
*NSET,NSET=SYMM,GENERATE
 2,18,1
 22,38,1
 42,58,1
 62,78,1
*NSET, NSET=QA_TEST
1,2,3,21,22,23,
**
** Water Nodes
**
*NODE,NSET=BP
  101, 0.81162,0.0,0.0
  119,-0.81162,0.0,0.0
 1601, 0.997095,0.0,0.0
 1619,-0.997095,0.0,0.0
 1701, 1.002905,0.0,0.0
 1719,-1.002905,0.0,0.0
 9201, 2.002905,0.0,0.0
 9219,-2.002905,0.0,0.0
**
*NGEN,NSET=IFN,LINE=C
 101,119,1,99998,,,,0,0,1
*NGEN,NSET=IFF,LINE=C
 1601,1619,1,99998,,,,0,0,1
*NGEN,NSET=OFN,LINE=C
 1701,1719,1,99998,,,,0,0,1
*NGEN,NSET=OFF,LINE=C
 9201,9219,1,99998,,,,0,0,1
**
*NFILL,NSET=BP
 IFN,IFF,15,100
 OFN,OFF,75,100
**
** Front Plane
**
*NCOPY,CHANGE NUMBER=50000,OLD SET=BP,SHIFT,NEW SET=FP
 0.0,0.0,0.175

**
** Shell Elements
**
*ELEMENT,TYPE=S4R
 1,  1, 2, 22, 21
 21,41,42, 62, 61
*ELGEN,ELSET=CYLINDER_I
 1,18,1,1,
*ELGEN,ELSET=CYLINDER_E
 21,18,1,1
**
** Water Elements
**
** This mesh density is 15 elements per 0.2 meter, resulting in an element length of 0.013.
**
*ELEMENT,TYPE=AC3D8R
 101,101,102,50102,50101,201,202,50202,50201
 1701,1701,1702,51702,51701,1801,1802,51802,51801
*ELGEN,ELSET=IWATER
 101,18,1,1,15,100,100
*ELGEN,ELSET=OWATER
 1701,18,1,1,75,100,100
*ELSET,ELSET=INEAR,GENERATE
 101,118,1
*ELSET,ELSET=IFAR,GENERATE
 1501,1518,1
*ELSET,ELSET=ONEAR,GENERATE
 1701,1718,1
*ELSET,ELSET=OFAR,GENERATE
 9101,9118,1
**
**
*SHELL SECTION, ELSET=CYLINDER_E, MATERIAL=STEEL_E
 0.00581,
*SHELL SECTION, ELSET=CYLINDER_I, MATERIAL=STEEL_I
 0.02324,
*SOLID SECTION, ELSET=IWATER, MATERIAL=FLUID_E
*SOLID SECTION, ELSET=OWATER, MATERIAL=FLUID_E
*MATERIAL, NAME=STEEL_E
*DENSITY
 7766.0,0.0       
*ELASTIC, TYPE=ISOTROPIC
 2.0640E+11,0.3,0.0       
*MATERIAL,NAME=STEEL_I
 *DENSITY
 7766.0,0.0       
*ELASTIC,TYPE=ISOTROPIC
 2.0640E+11,0.3,0.0
**
** NOTE THAT WE HAVE TAKEN THE FLUID PROPERTIES DIRECTLY
** FROM THE DERA DECK.  THESE VALUES DO NOT SATISFY K=C*C*RHO
**    
*MATERIAL,NAME=FLUID_I
*ACOUSTIC MEDIUM
 2.395488E9,
*DENSITY
 997.0,
*MATERIAL,NAME=FLUID_E
*ACOUSTIC MEDIUM
 2.315608E9,
*DENSITY
 997.0,
**
**
*AMPLITUDE,NAME=UNDEX,DEFINITION=TABULAR,TIME=TOTAL TIME
0.0,0.0,1.0E-6,1.0,10.0,1.0
**
**
*SURFACE,NAME=FLUID1
 INEAR,S1
*SURFACE,NAME=FLUID2
 IFAR,S2
*SURFACE,NAME=FLUID3
 ONEAR,S1
*SURFACE,NAME=QUIET
 OFAR,S2
*SURFACE,NAME=SOLID1
 CYLINDER_I,SPOS
*SURFACE,NAME=SOLID2
 CYLINDER_E,SNEG
*SURFACE,NAME=SOLID3
 CYLINDER_E,SPOS
**
**
*TIE,NAME=COUPLE
 FLUID1,SOLID1
 FLUID2,SOLID2
 FLUID3,SOLID3
**
**
*BOUNDARY
 SYMM,ZSYMM
 PLANE,2,6
**
**
*INCIDENT WAVE PROPERTY,NAME=WAVE,TYPE=PLANE
 1.002905,0.0,0.0,
 2.0,0.0,0.0
*INCIDENT WAVE FLUID PROPERTY
 2.315608E9,997.0
**
**
*STEP
*DYNAMIC,EXPLICIT,DIRECT USER CONTROL
 1.0E-7,0.00538
*INCIDENT WAVE,PROPERTY=WAVE,PRESSURE AMPLITUDE=UNDEX
 SOLID3,1.0E+06
 FLUID3,1.0E+06
*SIMPEDANCE,NON=CIRCULAR
 QUIET,2.002905
*BULK VISCOSITY
 0.25,10.0
*OUTPUT,FIELD
*NODE OUTPUT
 U,
*OUTPUT,FIELD,NUMBER=2
*NODE OUTPUT, NSET=QA_TEST
 U,
*OUTPUT,HISTORY,TIME INTERVAL=1.076E-6
*NODE OUTPUT,NSET=PLANE
 U,V
*END STEP