Small Signal Resonance Methods

The properties of a piezoelectric material are defined by the elastic, dielectric, and piezoelectric tensor components which will be introduced in Sect. 18.2. Because of the inherent asymmetrical nature of piezoelectric materials and the fact that we want to predict different response directions, a tensor-based description of the properties of these materials is unavoidable. Generally these components are by far not constant, they depend on temperature, applied mechanical stress and electric field strength. Furthermore, they are amplitude-dependent and become non-linear or even non-reversible when the applied signal stress or signal field amplitudes exceed limits characteristic of the material. The dielectric, elastic and piezoelectric coefficients have not only effective (real, in-phase) components but also dissipative (imaginary, out-of-phase) terms which are of particular importance at high amplitudes.