*HEADING
EXAMPLE PROBLEM: MODE 0 SPHERE USING BGT BOUNDARY CONDITION AND ACAX8.
*NODE,NSET=INNER
*NODE,NSET=MID
*NODE,NSET=OUTER
*ELEMENT, TYPE=ACAX8,ELSET=EALL
*ELGEN, ELSET=EALL
*ELEMENT,TYPE=ASI3A,ELSET=COUPLING
*ELGEN,ELSET=COUPLING
**
** FLUID MATERIAL PROPERTIES; ARTIFICIAL MEDIUM FOR CONVENIENCE
** USING RHO = 1, BULKMOD = (2*PI)^2, WE HAVE C = 2*PI AND K = F.
**
*MATERIAL,NAME=AETHER
*DENSITY
1.000000,
*ACOUSTIC MEDIUM,BULK MODULUS
*SOLID SECTION,MATERIAL=AETHER,ELSET=EALL
*INTERFACE,ELSET=COUPLING
**
** BAYLISS, GUNZBERGER, TURKEL FIRST ORDER CONDITION. EXACT
** FOR MODE 0 OF A SPHERE.
** SEE SIAM JAM 1982, V42 N2 P430FF.
**
** 1/C1 = 1/SQRT(K * RHO) = 1/2/PI
** 1/K1 =-1/(R *RHO * (2 PI F)^2 )
**
*IMPEDANCE PROPERTY,NAME=BGT1
*NSET,NSET=RECRD
*TRANSFORM,NSET=INNER,TYPE=S
*STEP
*STEADY STATE DYNAMIC,DIRECT
*IMPEDANCE
EALL, I3, BGT1
**
** SURFACE RADIAL ACCELERATION OF 1/(RHO C) MAGNITUDE
**
*BOUNDARY,TYPE=VELOCITY
INNER,1,1,0.159154943
INNER,2,2,0.0
*NODE PRINT,NSET=RECRD
POR,PPOR
*NODE FILE,NSET=RECRD
POR,PPOR
*OUTPUT,FIELD
*NODE OUTPUT
POR,
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=RECRD
POR,
*END STEP