Dynamic Characteristics Of Layered Periodic Piezoelectric Composites

ABSTRACT:Piezoelectric layered composites structures are widely used in various fields. With the development of material science and processing technology, they have become important new-type materials and structures. The unique characteristic so-called frequency band gap of periodic structure has brought a new direction for the study of dynamic character of piezoelectric composite. In this thesis, the frequency band gap property is introduced to design vibration characteristics of piezoelectric composites structures, which is of great significance for the piezoelectric composite transducer research.The main works include three parts as following:1. Band gap characteristics of layered periodic piezoelectric composites are studied. By using differential quadrature method and focusing the propagation of SH waves along the vertical direction, dispersion curves are obtained. Compared with other works, the correctness of the proposed method is proved. Meanwhile numerical simulations are conducted to verify the correctness of theoretical calculations.2. The theoretical solution of the characteristic frequencies of piezoelectric composite layered transducers is presented, which is in line with the experimental results. And the frequency-impedance curve of layered piezoelectric composites structure is simulated by ANSYS to verify the correctness of theoretical calculation.3. Periodic theory is applied to design piezoelectric composite layered device. The frequency-impedance curve and the characteristic frequencies of piezoelectric composite layered structure are calculated. The resonant frequency is completely decoupled with frequency band gap, which can be achieved maximum vibration characteristics. Dynamic property of a finite periodic layered structure is simulated by using ANSYS to verify the accuracy of theoretical calculations.