*HEADING
 1D transient wave propagation, acoustic medium, incident wave load, planar
 and defined through acceleration 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=ACCVTIME
0.0,-1.0,1.0,-1.0
**************************
*RESTART,WRITE
**
*STEP
*DYNAMIC,EXPLICIT
 ,.0044,
** DEFINE NONREFLECTIVE BOUNDARY AT X=1
*IMPEDANCE
 597,I4
 596,I2
**
*INCIDENT WAVE,ACCELERATIONAMPLITUDE=ACCVTIME,PROPERTY=IWPROP
IW_LOAD,1
**
*NSET,NSET=QA_TEST
ODB_NSET,
*OUTPUT,FIELD,NUMBER INTERVAL=2
*NODE OUTPUT
 POR,
*NODE OUTPUT,NSET=QA_TEST
 POR,
*OUTPUT,HISTORY,TIME INTERVAL=0.1E-3
*NODE OUTPUT,NSET=SAMPLE
 POR,
*ENDSTEP