*HEADING
1D TRANSIENT WAVE PROPAGATION IN AN ACOUSTIC MEDIUM WITH CLOAD
IN ABAQUS/EXPLICIT [AC3D8R];
VERIFICATION PROBLEM: TRANSIENT DYNAMICS TESTS
**
** C=SQRT(K/RHO)= 343.05 M/S   K=BULK MODULUS, 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
** FOR EXAMPLE AT THE END OF THE SIMULATION :
**              P_1(0,0.0044)=1.826
**              P_51(0.5,0.0044)=1.221
**              P_101(1.0,0.0044)=0.616
** THE ACCELERATION IS SPECIFIED USING *CLOAD ON DOF 8
**
** SEE CH. 3.7.7 OF ABAQUS/VERIFICATION MANUAL
**
*PREPRINT,ECHO=NO,HISTORY=NO,MODEL=NO
*NODE,NSET=NALL
*NGEN,NSET=NALL
*NSET,NSET=QA_TEST,GEN
*NSET,NSET=NOUT
QA_TEST,
*NSET,NSET=LOADED_NODES
*ELEMENT,TYPE=AC3D8R
*ELGEN,ELSET=CHANNEL
*SOLID SECTION,MATERIAL=AIR,ELSET=CHANNEL
**
*MATERIAL,NAME=AIR
*DENSITY
 1.21,
*ACOUSTIC MEDIUM,BULK MODULUS
**
** Define nonreflective boundary at x=1
** Using user calculated constants:
** 1/k1=0, 1/c1=1/(rho*c)
*IMPEDANCE PROPERTY,NAME=NONREF
**
*RESTART,WRITE,NUMBER=1
*STEP
*DYNAMIC,EXPLICIT
,.0044
** Define nonreflective boundary at x=1
*IMPEDANCE
 100,I4,NONREF
**
** Prescribe unit particle acceleration a0 inwards,
** so that _volume_ acceleration is a0 * cross-section.
**  Distribute 1/4 to each corner node:
*CLOAD
 LOADED_NODES,8,.25e-4
**
*************************
*OUTPUT,FIELD,NUMBER INTERVAL=1
*NODE OUTPUT
POR
*NODE OUTPUT,NSET=QA_TEST
POR,
*************************
***OUTPUT,HISTORY, TIME INTERVAL=0.00022
***NODE OUTPUT, NSET=NOUT
**POR
*************************
*END STEP