Table 1.

The characteristic properties of circular PZT sensors.

Items.	Parameters	Values
s11E (×10−12 m2/N)	Compliance coefficient	10.417
s12E (×10−12 m2/N)	In-plane compliance coefficient	−3.333
η	Mechanical loss factor	0.025
${\epsilon }_{33}{}^T/{\epsilon }_0$ (Farad/m)	Relative dielectric constant	1920
δ	Dielectric loss factor	0.01
d31 (C/N)	Piezoelectric strain constant	−200
ν	Poisson’s ratio	0.32
$\rho$ (kg/m3)	Density	7750
h (×10−3 m)	Thickness	0.33
r (×10−3 m)	Radius	4