Abstract
The sensitivity (M) of a piezoelectric is a function of its voltage coefficient (gij) and its thickness (t) as M ¼ gij.t. A poled piezoelectric ceramic such as PZT has five nonzero coefficients: g31 ¼ g32, g33, and g15 ¼ g24. For in-air applications, either the g33 (longitudinal mode) or g15 (shear mode) coefficients are typically used. When used in a hydrostatic mode, such as when fully immersed in water, the sensitivity is proportional to the hydrostatic g-coefficient (gh) which is equal to g33 þ 2g31. For a poled piezoelectric ceramic, g33E- 2g31 due to crystallographic symmetry arguments. Thus, the sensitivity of a monolithic piezoelectric ceramic under hydrostatic conditions is rather low. This is the main reason why piezoelectric ceramics are incorporated into composite configurations. Piezoceramic–polymer composites are designed to eliminate either the g31 or g33 contribution to gh. The manner in which the ceramic and polymer are self-connected throughout the composite volume has a marked effect on its properties. Composites with 0–3 connectivity are typically in the form of flexible rubber sheets. They are characterized by high sensitivity, high-pressure tolerance, a broad operating bandwidth, as well as a good acoustical impedance match to air or water. Piezocomposites with 1–3 connectivity have roughly the same performance characteristics as 0–3 s. Physically, though, they are more rigid, lighter in weight, and can be more easily tailored to application-specific needs. As seen in Table 3, other piezo-composite designs have not shown any marked advantage over the 0–3....
Original language | English (US) |
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Title of host publication | Testing, Nondestructive Evaluation and Structural Health Monitoring |
Publisher | Elsevier Inc. |
Pages | 408-419 |
Number of pages | 12 |
Volume | 7-8 |
ISBN (Electronic) | 9780081005347 |
ISBN (Print) | 9780081005330 |
DOIs | |
State | Published - Jan 1 2018 |
All Science Journal Classification (ASJC) codes
- General Engineering