*HEADING
UNDEX Benchmark Problem
Fluid Coupled Concentric Spheres, Inner Sphere Air Backed
**
** Shell Nodes
**
*NODE
    1, 0.0,-0.8
   65, 0.0, 0.8
  101, 0.0,-1.0
  165, 0.0, 1.0
99999, 0.0, 0.0
*NGEN,NSET=SPHERE_I,LINE=C
 1,65,1,99999,,,,0,0,1
*NGEN,NSET=SPHERE_E,LINE=C
 101,165,1,99999,,,,0,0,1
*NSET,NSET=SYMM
 1,65,101,165
**
** Water Nodes
**
*NODE
  201, 0.0,-0.808
  265, 0.0, 0.808
 2201, 0.0,-0.998
 2265, 0.0, 0.998
 3001, 0.0,-1.002
 3065, 0.0, 1.002
13001, 0.0,-3.002
13065, 0.0, 3.002
*NGEN,NSET=IWI,LINE=C
 201,265,1,99999,,,,0,0,1
*NGEN,NSET=IWO,LINE=C
 2201,2265,1,99999,,,,0,0,1
*NGEN,NSET=OWI,LINE=C
 3001,3065,1,99999,,,,0,0,1
*NGEN,NSET=OWO,LINE=C
 13001,13065,1,99999,,,,0,0,1
*NFILL,NSET=WATER
 IWI,IWO,10,200
 OWI,OWO,100,100
**
** Shell Elements
**
*ELEMENT,TYPE=SAX1
 1,2,1
 101,101,102
*ELGEN,ELSET=SPHERE_I
 1,64,1,1
*ELGEN,ELSET=SPHERE_E
 101,64,1,1
*SHELL SECTION,ELSET=SPHERE_I,MATERIAL=STEEL
 0.016,
*SHELL SECTION,ELSET=SPHERE_E,MATERIAL=STEEL
 0.004,
**
** Water Elements
** 
*ELEMENT,TYPE=ACAX4R
 200,201,401,402,202
 1000,3001,3101,3102,3002
*ELGEN,ELSET=IWATER
 200,64,1,1,10,200,64
*ELGEN,ELSET=OWATER
 1000,64,1,1,100,100,64
*SOLID SECTION,ELSET=IWATER,MATERIAL=WATER
 1.0,
*SOLID SECTION,ELSET=OWATER,MATERIAL=WATER
 1.0,
*ELSET,ELSET=IWI,GENERATE
 200,263,1
*ELSET,ELSET=IWO,GENERATE
 776,839,1
*ELSET,ELSET=OWI,GENERATE
 1000,1063,1
*ELSET,ELSET=OWO,GENERATE
 7336,7399,1
** 
** 
*MATERIAL,NAME=STEEL
*DENSITY
 7765.,
*ELASTIC
 2.246E+11, 0.3
*MATERIAL,NAME=WATER
*ACOUSTIC MEDIUM
 2.395488E+09,
*DENSITY
 997.,
**
**
*SURFACE,NAME=SOLID1
 SPHERE_I,SPOS
*SURFACE,NAME=SOLID2
 SPHERE_E,SPOS
*SURFACE,NAME=SOLID3
 SPHERE_E,SNEG
*SURFACE,NAME=FLUID1
 IWI,S4
*SURFACE,NAME=FLUID2
 IWO,S2
*SURFACE,NAME=FLUID3
 OWI,S4
*SURFACE,NAME=OUTER
 OWO,S2
**
**
*TIE,NAME=COUPLE
 FLUID1,SOLID1
 FLUID2,SOLID2
 FLUID3,SOLID3
**
**
*AMPLITUDE,NAME=UNDEX,DEFINITION=TABULAR,TIME=TOTAL TIME
 0.0,0.0,1.0E-6,1.0,1.0,1.0
**
**
*INCIDENT WAVE PROPERTY,NAME=WAVE,TYPE=PLANE
 0.0,1.002,0.0
 0.0,3.0,0.0
*INCIDENT WAVE FLUID PROPERTY
 2.395488e+09,997.0
**
**
*BOUNDARY
 SYMM,1,1
 SYMM,6,6
**
** ----------------------------------------------------------------
** 
** 
*STEP
*DYNAMIC,EXPLICIT,DIRECT USER CONTROL
 1.0E-7,0.0106
*INCIDENT WAVE,PROPERTY=WAVE,PRESSURE AMPLITUDE=UNDEX
 SOLID3,1.0E6
 FLUID3,1.0E6
*SIMPEDANCE,NON=SPHER
 OUTER,3.002
*BULK VISCOSITY
 0.2,1.2
*OUTPUT, FIELD
*NODE OUTPUT
 U,POR
*ELEMENT OUTPUT
 S,E
*OUTPUT,HISTORY,TIME INTERVAL=1.06E-4
*NODE OUTPUT,NSET=SYMM
 U,V
*END STEP