fini /clear,nostart !JPGPRF,500,100,1 ! MACRO TO SET PREFS FOR JPEG PLOTS !/SHOW,JPEG /TITLE,VM237, PIEZOELECTRIC-CIRCUIT ANALYSIS /COM, --------------------------------------------------------------- /COM, FINITE ELEMENT MODEL OF A PIEZOELECTRIC CIRCULAR PLATE /COM, --------------------------------------------------------------- A=1E-3 ! RADIUS, M T=0.1E-3 ! THICKNESS, M !2DO SUBS1=100 TIME1=2E-2 !1E-1 /COM, - COMPLIANCE COEFFICIENTS, M2/N S11=16.4E-12 S12=-5.74E-12 S13=-7.22E-12 S33=18.8E-12 S44=47.5E-12 S66=44.3E-12 /COM, - PIEZOELECTRIC STRAIN COEFFICIENTS, C/N D15=5.84E-10 D31=-1.71E-10 D33=3.74E-10 /COM, - RELATIVE PERMITTIVITY AT CONSTANT STRESS EP11=1730 EP33=1700 /COM, - DENSITY, KG/M3 RHO=7750 /NOPR /PREP7 TB,ANEL,1,,,1 ! ANISOTROPIC ELASTIC COMPLIANCE MATRIX TBDA,1,S11,S13,S12 TBDA,7,S33,S13 TBDA,12,S11 TBDA,16,S44 TB,PIEZ,1,,,1 ! PIEZOELECTRIC STRAIN MATRIX TBDA,2,D31 TBDA,5,D33 TBDA,8,D31 TBDA,10,D15 TB,DPER,1,,,1 ! DIELECTRIC PERMITTIVITY AT CONSTANT STRESS TBDA,1,EP11,EP33 TBLIS,ALL ! LIST INPUT AND CONVERTED MATRICES MP,DENS,1,RHO ! DENSITY !2DO MP,LSST,1,0.5 ! 0.17 ! ca10deg ET,1,PLANE223,1001,,1 ! PIEZOELECTRIC AXISYMMETRIC ELEMENT TYPE RECT,,A,,T ESIZE,T ! MESH SOLID MODEL NUMSTR,NODE,10 AMESH,1 ! APPLY STRUCTURAL BC, SIMPLY SUPPORTED PLATE NSEL,S,LOC,X D,ALL,UX,0 NSEL,S,LOC,X,A NSEL,R,LOC,Y,0 D,ALL,UY,0 NSEL,ALL ! APPLY ELECTRIC BC NSEL,S,LOC,Y,0 CP,1,VOLT,ALL ! COUPLE BOTTOM ELECTRODE *GET,NBOT,NODE,0,NUM,MIN ! GET MASTER NODE ON BOTTOM ELECTRODE NSEL,S,LOC,Y,T CP,2,VOLT,ALL ! COUPLE TOP ELECTRODE *GET,NTOP,NODE,0,NUM,MIN ! GET MASTER NODE ON TOP ELECTRODE NSEL,ALL D,NBOT,VOLT,0 ! GROUND BOTTOM ELECTRODE D,NTOP,VOLT,1 ! APPLY 1V LOAD ON TOP ELECTRODE FINI /SOLU ANTYPE,STATIC ! STATIC ANALYSIS SOLVE FINI /POST1 *GET,QT,NODE,NTOP,RF,CHRG ! GET TOTAL CHARGE ON TOP ELECTRODE CP=ABS(QT) ! CAPACITANCE CP=Q/V, WHERE V=1V EPZ0=8.854E-12 ! FREE SPACE PERMITTIVITY PI=3.1415 ! PI CONSTANT C=EP33*EPZ0*PI*A**2/T ! ANALYTICAL CAPACITANCE /COM, 2-D CAPACITANCE (ANALYTICAL) =%C%, F /COM, 2-D CAPACITANCE (ANSYS) = %CP%, F FINI /COM, --------------------------------------------------------------- /COM, FINITE ELEMENT MODEL OF RLC-CIRCUIT /COM, --------------------------------------------------------------- /PREP7 DDELE,NTOP,VOLT ! DELETE VOLTAGE LOAD ON TOP ELECTRODE !ET,2,CIRCU94,0 ! DEFINE A RESISTOR !R=3000 ! RESISTANCE, OHM !R,1,R !N,1 !TYPE,2 !REAL,1 !E,1,NTOP ! !ET,3,CIRCU94,1 ! DEFINE AN INDUCTOR !L=15 ! INDUCTANCE, H !R,2,L !N,2 !TYPE,3 !REAL,2 !E,2,1 ! !ET,4,CIRCU94,4 ! DEFINE A VOLTAGE SOURCE !V=1 ! VOLTAGE LOAD, V !R,3,V !N,3 !TYPE,4 !REAL,3 !E,2,NBOT,3 !2DO /INPUT,Load220,func,,:FUNC D,NTOP,VOLT,%load220% ! APPLY 1V LOAD ON TOP ELECTRODE FINI /SOLU ANTYPE,TRANS ! TRANSIENT ANALYSIS NSUB,SUBS1 ! NUMBER OF TIME STEPS TIME,TIME1 ! ANALYSIS TIME, S TINTP,,0.25,0.5,0.5 ! INTEGRATION PARAMETERS FOR A PIEZOELECTRIC ANALYSIS OUTRES,ALL,ALL SOLVE FINI ! /GOPR ! /COM, ANALYTICAL SOLUTION: ! /COM, V_C = 1-EXP(-D*T)*COS(B*T)-D/B*EXP(-D*T)*SIN(B*T) ! /COM, WHERE: ! D=R/(2*L) ! B=SQRT(1/(L*C)-D**2) ! /NOPR ! /POST26 NUMVAR,200 NSOL,2,NTOP,VOLT,,V_C_ANSYS *afun,rad ! ! DERIVE EXACT SOLUTION ! *DIM,WORK1,ARRAY,SUBS1 ! *DIM,WORK2,ARRAY,SUBS1 ! FILLDATA,3,,,,1 ! 1 ! EXP,4,1,,,,,,-D,-1 ! -EXP(-D*T) ! PROD,5,1,,,,,,B ! B*T ! VGET,WORK1(1),5 ! *VFUN,WORK2(1),COS,WORK1(1) ! VPUT,WORK2(1),6 ! COS(B*T) ! *VFUN,WORK2(1),SIN,WORK1(1) ! VPUT,WORK2(1),7 ! SIN(B*T) ! ADD,8,6,7,,,,,,D/B ! COS(B*T) + D/B*SIN(B*T) ! PROD,9,4,8 ! -EXP(-D*T)*[COS(B*T) + D/B*SIN(B*T)] ! ADD,10,3,9,,V_C_EXACT ! 1-EXP(-D*T)*[COS(B*T) + D/B*SIN(B*T)] ! ! PRINT AND PLOT ANSYS AND EXACT VOLTAGE ACROSS THE PZT CAPACITOR !2DO NSOL,11,NTOP,UY,,UY_ANSYS XVAR,11 PLVAR,2 /eof PRVAR,2,10 PLVAR,2,10 /NOPR *DIM,VCE,ARRAY,5 ! EXACT SOLUTION FOR RESULTS TABLE *DIM,VCA,ARRAY,5 ! ANSYS SOLUTION FOR RESULTS TABLE *GET,VCE(1),VARI,10,RTIME,0.18E-2 *GET,VCE(2),VARI,10,RTIME,0.40E-2 *GET,VCE(3),VARI,10,RTIME,0.88E-2 *GET,VCE(4),VARI,10,RTIME,0.13E-1 *GET,VCE(5),VARI,10,RTIME,0.186E-1 *GET,VCA(1),VARI,2,RTIME,0.18E-2 *GET,VCA(2),VARI,2,RTIME,0.40E-2 *GET,VCA(3),VARI,2,RTIME,0.88E-2 *GET,VCA(4),VARI,2,RTIME,0.13E-1 *GET,VCA(5),VARI,2,RTIME,0.186E-1 *DIM,LABEL,CHAR,5 *DIM,VALUE,,5,3 LABEL(1) = '1.8E-2s','4.0E-2s','8.8E-2s','1.3E-1s','1.86E-1s' *VFILL,VALUE(1,1),DATA,VCE(1),VCE(2),VCE(3),VCE(4),VCE(5) *VFILL,VALUE(1,2),DATA,VCA(1),VCA(2),VCA(3),VCA(4),VCA(5) V1 = VCA(1)/VCE(1) V2 = VCA(2)/VCE(2) V3 = VCA(3)/VCE(3) V4 = VCA(4)/VCE(4) V5 = VCA(5)/VCE(5) *VFILL,VALUE(1,3),DATA,ABS(V1),ABS(V2),ABS(V3),ABS(V4),ABS(V5) /OUT,vm237,vrt /COM /COM,------------------- VM237 RESULTS COMPARISON --------------------- /COM, /COM, | TARGET | ANSYS | RATIO /COM, /COM, VC for t @ ... /COM *VWRITE,LABEL(1),VALUE(1,1),VALUE(1,2),VALUE(1,3) (1X,A8,' ',F12.4,' ',F12.4,' ',1F5.3) /COM,---------------------------------------------------------------- /OUT FINI *LIST,vm237,vrt