*HEADING
 EC3FAFAS: AC3D15 AND ASI4
 1D transient wave propagation in an acoustic medium with 
 prescribed acceleration on dof 1.
 Verification problem: Transient Dynamics Tests
**
** C = root (K/rho)= 343.05 m/s   K=bulk mod, rho=density.  
**
** Analytic solution to prescribed constant acceleration of a0 at x=0
** 
** p(x,t) = (K a0 / c^2) (ct - x)  for x < ct
**        = 0  			   for x > ct
** 
*PREPRINT,ECHO=NO,HISTORY=YES,MODEL=YES
**
*part,name=old
*NODE, Nset=ODB_NSET
    1, 0,
  101, 1,
  501, 0,.5e-2
  601, 1,.5e-2
 1001, 0, 1.e-2
 1101, 1, 1.e-2
 1501, 0, 1.e-2, -1.e-2
 1601, 1, 1.e-2, -1.e-2
 2001, 0, 1.e-2, -0.5e-2
 2101, 1, 1.e-2, -0.5e-2
 2501, 0, 0, -1.e-2
 2601, 1, 0, -1.e-2
 3001, 0,.5e-2, -1.e-2
 3101, 1,.5e-2, -1.e-2
 3501, 0, 0, -0.5e-2
 3601, 1, 0, -0.5e-2
 4001, 0, 0.5e-2, -0.5e-2
 4101, 1, 0.5e-2, -0.5e-2
*NGEN,NSET=CHANNEL
    1,101
  501,601
 1001,1101
 1501,1601
 2001,2101
 2501,2601
 3001,3101
 3501,3601
 4001,4101
*NSET,NSET=SAMPLE,GENERATE
 1,101
*NSET,NSET=LOAD
 1,1001,1501,2501,501,2001,3001,3501
*NSET,NSET=LOADED
 1,1001,1501,2501
*NSET,NSET=EDGELOAD
 501,2001,3001,3501
*NSET,NSET=LOADED
1,1001,1501,2501
*ELEMENT,TYPE=AC3D15
    1,    1, 1001,    3, 2501, 1501, 2503,
          501,  502,    2, 3001, 3002, 2502,
         3501, 2001, 3503,
    2,    3, 1001, 1003, 2503, 1501, 1503,
          502, 1002,  503, 3002, 1502, 3003,
         3503, 2001, 2003,
*ELGEN,ELSET=CHANNEL
 1,50,2,2
 2,50,2,2
*SOLID SECTION,MATERIAL=AIR,ELSET=CHANNEL
*ELEMENT,TYPE=ASI4,ELSET=LOAD
 1200,1,2501,1501,1001,
*INTERFACE, ELSET=LOAD
*endpart
*part,name=new
*NODE, Nset=ODB_NSET
    1, 0,
  101, 1,
  501, 0,.5e-2
  601, 1,.5e-2
 1001, 0, 1.e-2
 1101, 1, 1.e-2
 1501, 0, 1.e-2, -1.e-2
 1601, 1, 1.e-2, -1.e-2
 2001, 0, 1.e-2, -0.5e-2
 2101, 1, 1.e-2, -0.5e-2
 2501, 0, 0, -1.e-2
 2601, 1, 0, -1.e-2
 3001, 0,.5e-2, -1.e-2
 3101, 1,.5e-2, -1.e-2
 3501, 0, 0, -0.5e-2
 3601, 1, 0, -0.5e-2
 4001, 0, 0.5e-2, -0.5e-2
 4101, 1, 0.5e-2, -0.5e-2
*NGEN,NSET=CHANNEL
    1,101
  501,601
 1001,1101
 1501,1601
 2001,2101
 2501,2601
 3001,3101
 3501,3601
 4001,4101
*NSET,NSET=SAMPLE,GENERATE
 1,101
*NSET,NSET=LOAD
 1,1001,1501,2501,501,2001,3001,3501
*NSET,NSET=LOADED
 1,1001,1501,2501
*NSET,NSET=EDGELOAD
 501,2001,3001,3501
*NSET,NSET=LOADED
1,1001,1501,2501
*ELEMENT,TYPE=AC3D15
    1,    1, 1001,    3, 2501, 1501, 2503,
          501,  502,    2, 3001, 3002, 2502,
         3501, 2001, 3503,
    2,    3, 1001, 1003, 2503, 1501, 1503,
          502, 1002,  503, 3002, 1502, 3003,
         3503, 2001, 2003,
*ELGEN,ELSET=CHANNEL
 1,50,2,2
 2,50,2,2
*SOLID SECTION,MATERIAL=AIR,ELSET=CHANNEL
*ELEMENT,TYPE=ASI3D8,ELSET=LOAD
 1200,1,2501,1501,1001, 3501,3001,2001,501
*INTERFACE, ELSET=LOAD
*endpart
**
*assembly,name=both
*instance,name=old,part=old
*endinstance
*instance,name=new,part=new
0,0.05,0
*endinstance
*nset,nset=sample
old.sample,new.sample
*nset,nset=load
old.load,new.load
*surface,NAME=NRS
 old.100,S5,
 new.100,S5,
*endassembly
**************************************
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
**
**
*RESTART,WRITE
**
*STEP,INC=1000
*DYNAMIC,DIRECT,APPLICATION=TRANSIENT FIDELITY
.0001,.0036
** Define nonreflective boundary at x=1
*IMPEDANCE
 old.100,I5
 new.100,I5
**
**  Prescribe unit _particle_ acceleration a0 inwards;
**
*BOUNDARY,TYPE=ACCELERATION
 LOAD,1,1,1.
*EL PRINT,FREQ=0
*NODE PRINT,NSET=SAMPLE,FREQ=6
 POR,
*NODE FILE,NSET=SAMPLE,FREQ=6
 POR,
*OUTPUT,FIELD, OP=NEW,Frequency=6
*NODE OUTPUT
 POR,
*OUTPUT,HISTORY,OP=ADD,Frequency=6
*NODE OUTPUT,NSET=SAMPLE
 POR,
*ENDSTEP
***********************
*STEP,INC=1000
*DYNAMIC,DIRECT,APPLICATION=TRANSIENT FIDELITY
.0001,.0008
*IMPEDANCE,OP=NEW
*SIMPEDANCE
 NRS,
*BOUNDARY,TYPE=ACCELERATION
 LOAD,1,1,1.
*EL PRINT,FREQ=0
*NODE PRINT,NSET=SAMPLE,FREQ=6
 POR,
*NODE FILE,NSET=SAMPLE,FREQ=6
 POR,
*OUTPUT,FIELD, OP=NEW,Frequency=6
*NODE OUTPUT
 POR,
*OUTPUT,HISTORY,OP=ADD,Frequency=6
*NODE OUTPUT,NSET=SAMPLE
 POR,
*ENDSTEP