Composite Materials Research Progress

268 Yasuhide Shindo and Fumio Narita
E 0=
-0.22 M V/m
-0.30 M V/m
Poling
0.5 m m
+0.22 M V/m
+0.30 M V/m
W ork
o
90 switching
o
180 switching
Figure 9. Normal stress versus r for disk composite tension actuator under E0 =0.2
MV/m.
C-91 + /C-91 − disk tension actuator with b =8mm. The predictions based on work (Eq.
(19)) and energy density (Eq. (26)) are shown. As the electric field is reduced from zero,
the compressive strain increases. Local polarization switching can cause a decrease in
compressive strain near the circular electrode tip. Little difference is observed between
two criteria. As the positive electric field increases, polarization switching did not occur.
Fig. 9 shows the distribution of the normal stress σzz as a function of r at z =0and 0.2
mm for C-91 + /C-91 − disk tension actuator with b =8mm under E0 =0.2 MV/m. Near
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Figure 10. Shear stress versus r for disk composite tension actuator under E0 = 0.2