SLAAEP2 January 2026 ULC1001
The dimensions of the piezo used in the LCS are listed in Table 5-4.
| Paramters | Unit | Value |
|---|---|---|
| Inner Diameter | mm | 15 |
| Outer Diameter | mm | 21 |
| Thickness | mm | 1.5 |
PZT8 is used in the LCS and its material properties are listed in Table 5-2. Other common piezo materials and their material properties are also listed in the table.
Symbol | Description | Unit | Navy Type VI (PZT 5H) | Navy type I (PZT 4) | Navy Type II (PZT 5A) | Navy Type III (PZT 8) |
|---|---|---|---|---|---|---|
e1,rX | Relative permittivity | 1 | 3244.97 | 1193.04 | 1795.99 | 1219.69 |
| e3,rX | Relative permittivity | 1 | 3984.62 | 1325.63 | 1802.77 | 989.52 |
tan d (3X) | dielectric dissipation factor | 1 | 0.016 | 0.003 | 0.017 | 0.004 |
d31 | piezoelectric charge constant | C/N | -2.59e-10 | -1.28e-10 | -1.70e-10 | -1.14e-10 |
d33 | piezoelectric charge constant | C/N | 6.4e-10 | 3.28e-10 | 4.25e-10 | 2.75e-10 |
d15 | piezoelectric charge constant | C/N | 6.16e-10 | 3.27e-10 | 5.06e-10 | 4.03e-10 |
Qm,t | mechanical quality factor | 1 | 59 | 373 | 74 | 1088 |
p | density | kg/m3 | 7780 | 7700 | 7700 | 7700 |
s11e | compliance matrix | m2/N | 1.82e-11 | 1.30e-11 | 1.7e-11 | 1.26e-11 |
| s12e | compliance matrix | m2/N | -7.76e-12 | -4.35e-12 | -6.6e-12 | -3.71e-12 |
| s13e | compliance matrix | m2/N | -6.85e-12 | -7.05e-12 | -8.61e-12 | -6.6e-12 |
| s33e | compliance matrix | m2/N | 1.8e-11 | 1.96e-11 | 2.32e-11 | 1.83e-11 |
s44e,s55e | compliance matrix | m2/N | 3.8e-11 | 3.32e-11 | 4.35e-11 | 3.77e-11 |
s66e | compliance matrix | m2/N | 5.2e-11 | 3.47e-11 | 4.71e-11 | 3.26e-11 |
The transducer is a ring shape and is poled in the top/bottom direction. Figure 5-1 shows the geometry drawing in COMSOL.
Figure 5-1 Transducer Geometry in COMSOLFigure 5-2 shows the coordinate system selection, where the Material XZ-plane System is selected.
Figure 5-2 Piezo: Coordinate System SelectionProperly setting the damping is crucial in mechanical modeling. Two types of damping are incorporated: mechanical damping and dielectric loss. The damping factor is calculated automatically based on the material properties. Figure 5-3 and Figure 5-4 show the damping settings of the piezo in the COMSOL.
Figure 5-3 Piezo: Mechanical DampingThe loss factor related to electrical permittivity is calculated automatically based on the properties of the piezo material.
Figure 5-4 Piezo: Dielectric LossThe piezo electrodes are situated on both the top and bottom surfaces of the piezo component, leading us to designate Terminal 2 and Terminal 3 as the two terminals for the electrostatics. Figure 5-5 shows the screenshot of the terminal selection.
Figure 5-5 Piezo: Terminal SelectionBy conducting the Frequency Domain study, we can observe the impedance response ranging from 20 kHz to 700 kHz, as illustrated in Figure 5-6 below. The first mode, occurring at 59 kHz, is identified as a radial mode, where both the inner and outer diameters of the piezo change uniformly while maintaining a constant width. In contrast, the second mode at 525 kHz represents the thickness mode, characterized by variations in both thickness and width.
Figure 5-6 Impedance Response of the Piezo Transducer.