39.4. Material Properties

The structural material properties used in this problem (taken from Yan [1]) are as follows:

Material Elastic Modulus (Pa) Poisson's Ratio Density (Kg/m3)
Alumina 3e11.23720
Aluminum 7e10.32700
PZT9.2e10.337700
Steel2.1e11.37800
Titanium1.1e11.324430

Piezoelectric materials typically have orthotropic material properties, although isotropic materials are assumed in this example, as they are defined in that manner in the reference.

The piezoelectric materials properties (taken from Berlincourt [3]) are as follows:

Relative permittivity in x, y

762

Relative permittivity in z

663

Piezoelectric constant e13

-5.2028

Piezoelectric constant e23

-5.2028

Piezoelectric constant e33

15.0804

Piezoelectric constant e52

12.7179

Piezoelectric constant e61

12.7179

A system damping ratio of 0.1 percent is assumed for the model, as the ultrasonic transducer has very little damping.