Acoustic excitation of piezoelectric composite material

Composite material has been proved to be efficient due to its strong electr omechanical coupling, low acoustic impedance and weak lateral coupling. In this paper, based on the dynamic model, the electromechanical coupling coef ficient and the internal vibration fields under various combination ratios are calculated. The results show that their variations can be well explaine d by the mode coupling. The electromechanical coupling reaches its maximum, when the thickness resonance mode is decoupled with the lateral resonance mode. This case happens only at a particular frequency and at a certain vol ume ratio between ceramic and polymer phases. Under this condition, the cer amic and polymer parts are separately in their resonant status.