*HEADING
RESONANT FREQUENCIES OF CLOSED-CIRCUITED PIEZOELECTRIC CUBE
QUARTER OF CUBE IS MODELED USING SYMMETRY CONDITIONS
REFINED MODEL WITH C3D8E ELEMENTS
*RESTART,WRITE
*NODE
*NGEN,NSET=A
*NGEN,NSET=B
*NGEN,NSET=C
*NGEN,NSET=D
*NFILL,NSET=SIDEA
A,B,8,10
*NFILL,NSET=SIDEB
C,D,8,10
*NFILL
SIDEA,SIDEB,16,100
*ELEMENT,TYPE=C3D8E
*ELGEN,ELSET=ALL
**local orientation matching global system
*ORIENTATION,NAME=RECT
*SOLID SECTION,MATERIAL=PZT,ELSET=ALL,ORIENT=RECT
*MATERIAL,NAME=PZT
*ELASTIC,TYPE=ORTHOTROPIC
13.2E10,7.1E10,13.2E10,7.3E10,7.3E10,11.5E10,3.0E10,2.6E10
2.6E10,
*PIEZOELECTRIC,TYPE=S
*DIELECTRIC,TYPE=ORTHO
*DENSITY
7.5E3,
** GENERATE NODE SETS FOR THE TOP AND BOTTOM ELECTRODES.
** CURRENTLY IT IS SETUP FOR FULLY COVERING ELECTRODES. COMMENT OUT THE
** NODE SPECIFICATIONS IN THE FOLLOWING WHERE NOTED TO OBTAIN THE
** PARTIALLY COVERING ELECTRODES.
*NSET,NSET=BOTELECT,GENERATE
** COMMENT OUT THE NEXT 9 LINES TO OBTAIN THE PARTIALLY COVERING ELECTRODE
*NSET,NSET=TOPELECT,GENERATE
** COMMENT OUT THE NEXT 9 LINES TO OBTAIN THE PARTIALLY COVERING ELECTRODE
*NSET,NSET=MID,GENERATE
*NSET,NSET=XSIDE,GENERATE
*NSET,NSET=YSIDE,GENERATE
*BOUNDARY
** SYMMETRY ON PLANES OF SYMMETRY
XSIDE,YSYMM
YSIDE,XSYMM
** FOR BREATHING-TYPE MODES, DISPLACEMENTS HAVE SYMMETRY ABOUT XY-PLANE
MID,3
** FOR CLOSED-CIRCUITED CASE, SET BOTTOM AND TOP ELECTRODES TO ZERO.
TOPELECT,9
BOTELECT,9
** GENERATE NSETS USED IN RESTRAINTS FOR BREATHING-TYPE MODES ONLY
*NSET,NSET=DIAG,GENERATE
*NSET,NSET=XCORNERS,GENERATE
*NSET,NSET=YCORNERS,GENERATE
** APPLY EQUATIONS TO ENSURE BREATHING-TYPE MODES ONLY ARE EXTRACTED
*EQUATION
DIAG,1,1.,DIAG,2,-1.
XCORNERS,1,1.,YCORNERS,2,-1.
XCORNERS,3,1.,YCORNERS,3,-1.
**
**
*STEP,PERTURBATION
EXTRACT BREATHING MODES UP TO 100000 HZ
*FREQUENCY, eigensolver=lanczos, SIM=NO
5, ,100000.,10000.
*ELSET,ELSET=ELOUT
*NSET,NSET=NOUT
*EL PRINT,ELSET=ELOUT
S,
E,
EFLX,EPG
*NODE PRINT,NSET=NOUT
U,EPOT
*NODE FILE, LAST MODE=1, NSET=NOUT
U,EPOT,RF,RCHG
*EL FILE, LAST MODE=1, ELSET=ELOUT
S,E,EFLX,EPG
*OUTPUT,FIELD
*NODE OUTPUT
U,
*NODE OUTPUT,NSET=NOUT
EPOT,RF,RCHG
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=NOUT
U,EPOT,RF,RCHG
*OUTPUT,FIELD
*ELEMENT OUTPUT,ELSET=ELOUT
S,E,EFLX,EPG
*OUTPUT,HISTORY
*ELEMENT OUTPUT,ELSET=ELOUT
S,E,EFLX,EPG
*END STEP