*HEADING
 1D transient wave propagation, acoustic medium, incident wave load, planar
 and defined through pressure amplitude
**
** C = root (K/rho)= 343.05 m/s   K=bulk mod, rho=density.  
**
** Analytical 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=NO,MODEL=YES
*NODE, NSET=ODB_NSET
    1, 0,
  101, 1,
 1001, 0, 1E-2
 1101, 1, 1E-2
 1501, 0, 1E-2, -1E-2
 1601, 1, 1E-2, -1E-2
 2501, 0, 0, -1E-2
 2601, 1, 0, -1E-2
*NGEN,NSET=CHANNEL
    1,101
 1001,1101
 1501,1601
 2501,2601
*NSET,NSET=SAMPLE,GENERATE
 1,101
*ELEMENT,TYPE=AC3D4
    1,    1, 1002,    2, 2501
    2, 1002,    2, 2501, 1502
    3,    2, 2501, 1502, 2502
    4,    1, 1001, 1002, 2501
    5, 1001, 1002, 2501, 1501
    6, 1002, 2501, 1501, 1502
*ELGEN,ELSET=CHANNEL
 1,100,1,6
 2,100,1,6
 3,100,1,6
 4,100,1,6
 5,100,1,6
 6,100,1,6
**************************
*SURFACE,NAME=IW_LOAD
 4,S2
 5,S4
**************************
*SOLID SECTION,MATERIAL=AIR,ELSET=CHANNEL
**
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
 0.1424E6,
**
**************************
*INCIDENT WAVE PROPERTY,NAME=IWPROP,TYPE=PLANE
0.0,0.0,
-10.0,0.0,
*INCIDENT WAVE FLUID PROPERTY
0.1424E6,1.21,0.0
*AMPLITUDE,DEFINITION=TABULAR,NAME=PRESSUREVTIME
0.0,0.0,1.0,-1.0
**************************
*RESTART,WRITE
**
*STEP,INC=1000
*DYNAMIC
.0001,.0044
** DEFINE NONREFLECTIVE BOUNDARY AT X=1
*IMPEDANCE
 597,I4
 596,I2
**
*INCIDENT WAVE,PRESSUREAMPLITUDE=PRESSUREVTIME,PROPERTY=IWPROP
IW_LOAD,415.09517
**
*EL PRINT,FREQ=0
*NODE PRINT,NSET=SAMPLE,FREQ=22
 POR,
*OUTPUT,FIELD,FREQUENCY=1
*NODE OUTPUT
 POR,
*OUTPUT,HISTORY,FREQUENCY=1
*NODE OUTPUT,NSET=SAMPLE
 POR,
*ENDSTEP