Composite Materials Research Progress

Eletromechanical Field Concentrations and Polarization Switching... 267
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Figure 7. A piezoelectric disk composite actuator.
4.2. Numerical Results and Discussion
We consider C-91 + /C-91 − and C-91 + /C-91 + with c =10mm and 2h =2mm, corresponding
to the tension and bending actuator models, respectively. The superscripts − and
+ denote, respectively, the situations for negative and positive poling directions.
Plotted in Fig. 8 are the numerical values of radial strain εrr near the circular internal
electrode tip (r =9mm and z =0.2 mm) as a function of electric field E0 = V0/h for
Strain,� rr (�10 -6 )
60
40
20
0
C-91 + /C-91 +
c= 10 m m
2h = 2 m m
b = 8 m m FEA
W ork
Energy density
-0.2 0 0.2
Electric field, E0 (M V/m )
!
r= 9 m m
z= 0.2 m m
Figure 8. Strain versus electric field for disk composite tension actuator.