*HEADING
 EC3A8AFAT: AC3D10 AND C3D8 ELEMENTS
 Tube with nonreflective end-condition and *TIE constraint.
 Part of the air in the tube is modelled with continuum elements
 with air properties.
************************************************
*NODE, Nset=ODB_NSET
1, 
41,.5
101,,0.0125
141,0.5,0.0125
201,,0.025
241,0.5,0.025
*NGEN,NSET=NBACK
1,41
101,141
201,241
*NCOPY,CHANGE NUMBER=300, OLD SET=NBACK, NEW SET=NMID,SHIFT
0.0,0.0,0.0125

*NCOPY,CHANGE NUMBER=600, OLD SET=NBACK, NEW SET=NFRONT,SHIFT
0.0,0.0,0.025

*NSET,NSET=NALL
NBACK,NFRONT,NMID
*NSET,NSET=SAMPLE,GEN
1,41
*NSET,NSET=LOAD1
1,201,801,601
*NSET,NSET=LOAD2
101,501,701,301
************************************************
*NCOPY,OLDSET=NALL,NEWSET=NSOL,CHANGENUMBER=1000,SHIFT
0.0,0.0,0.0
1.0,0.0,0.0,0.0,1.0,0.0
************************************************
** First 30 elements are acoustic quadratic tets
*ELEMENT,TYPE=AC3D10
   101,    1,  201,  601,    3,  101,  401,  301,
            2, 102, 302,
   102,  201,  601,    3,  203,  401, 302, 102,
          202, 402,  103,
   103,  601,    3,  203,  603, 302,  103, 402,
          602,  303,  403,
   104,  601,  201,  801,  603,  401,  501,  701,
          602, 402, 702,
   105,  201,  801,  603,  203,  501, 702, 402,
          202, 502,  403,
   106,  801,  603,  203,  803, 702,  403, 502,
          802,  703,  503,
*ELGEN,ELSET=ACOU
101,5,2,6
102,5,2,6
103,5,2,6
104,5,2,6
105,5,2,6
106,5,2,6
**
** Then 5 continuum elements
*ELEMENT,TYPE=C3D8
1006,1011,1611,1613,1013,  1211,1811,1813,1213,
*ELGEN,ELSET=STRUCT
1006,5,2,1
**
** Next elements are acoustic quadratic tets
*ELEMENT,TYPE=AC3D10
   11,   21,  221,  621,   23,  121,  421,  321,
           22,  122,  322,
   12,  221,  621,   23,  223,  421,  322,  122,
          222,  422,  123,
   13,  621,   23,  223,  623,  322,  123,  422,
          622,  323,  423,
   14,  621,  221,  821,  623,  421,  521,  721,
          622,  422,  722,
   15,  221,  821,  623,  223,  521,  722,  422,
          222,  522,  423,
   16,  821,  623,  223,  823,  722,  423,  522,
          822,  723,  523,
*ELGEN,ELSET=ACOU
11,10,2,6
12,10,2,6
13,10,2,6
14,10,2,6
15,10,2,6
16,10,2,6
************************************************
*SURFACE,TYPE=ELEMENT,NAME=ACR
127,S3
130,S3
*SURFACE,TYPE=ELEMENT,NAME=SOL
1006,S3
*SURFACE,TYPE=ELEMENT,NAME=SOR
1010,S5
*SURFACE,TYPE=ELEMENT,NAME=ACL
11,S1
14,S1
*TIE,NAME=CRAVAT
ACR,SOL
ACL,SOR
************************************************
**
**  Acoustic Element Properties
**
*SOLID SECTION,MATERIAL=AIR,ELSET=ACOU
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
************************************************
**
**  Continuum Element Properties
**
*SOLID SECTION,MATERIAL=AIRSOLID,ELSET=STRUCT
*MATERIAL,NAME=AIRSOLID
*DENSITY
 1.21,
*ELASTIC
 0.1424E6,
************************************************
*AMPLITUDE,NAME=OMEGA
0.,0., 1E6,6.2831853E6
************************************************
**       ** ANALYTIC SOLUTION  **
**  
**  at freq=100,
**  Impedance: Z = root( K_f rho )
**               = 415.095
**  Propagation constant 
**             b = i (omega/K_f) Z
**               = 1.8315  i
**
**  Solution: with nonreflective end,
**  Complex pressure
**             p(x) = Z v(0) exp( - b x)
**  i.e. |p(x)| = |Z v(0)| exp ( - Re(b) x)
**              =  415.095
**
**       Arg(p) = Arg(Z) - Im(b) x
**       ppor   = - 104.94 x
**
************************************************  
*Elset,Elset=ODB_ESET
ACOU
*Nset, Nset=ODB_NSET
ODB_NSET, NBACK, NMID, NFRONT
NALL, SAMPLE, LOAD1, LOAD2
************************************************  
*STEP
*STEADY STATE DYNAMIC,DIRECT
100,
**  For reference, these IMPEDANCE PROPERTY
**  constants could be used to specify the nonreflecting 
**  condition at the given frequency:
**  1/k1= 0, 1/c1= 2.40908E-03
**        0,       1/Z
**
*IMPEDANCE
 67,I3
 70,I3
**
** Conditions at x=0 : Define the source inward accel
** to be  a =  omega i, so v (inward) = 1.
** *AMPLITUDE card enforces (2*pi)*f factor. 
** *CLOAD needs only to carry total area, distributed
** to nodes.
** for end-on CLOAD's of wedges, the uniform distributed
** acceleration ends up with point loads of (0, 1/6, 1/3)
** on the (corner, edgemidside, facecenter), respectively,
** times the acceleration magnitude and area.
**
*CLOAD,LOAD CASE=2, AMP=OMEGA
LOAD2, 8,  1.0416667E-04
401,   8,  2.0833333E-04
** simulation of uniaxial condition
*BOUNDARY
NSOL,2,3
*NODE PRINT, NSET=SAMPLE
COORD,POR,PPOR
*OUTPUT,FIELD,OP=ADD,FREQUENCY=9999
*ELEMENT OUTPUT,ELSET=STRUCT
S
*NODE OUTPUT,NSET=SAMPLE
POR,
*OUTPUT,HISTORY,OP=ADD,FREQUENCY=9999
*NODE OUTPUT,NSET=SAMPLE
POR,
*ELEMENT OUTPUT,ELSET=STRUCT
COORD,S11
*END STEP