바이몰프형 압전 진동자의 경계조건 및 재질에 따른 진동특성해석

Abstract

Piezoelectric bimorph has been widely used as sensors and actuators in industry. However, it is hard to design and optimize because a lot of design factors. In order to solve this problem, in this paper, the general solution was found by deriving the equation of motion for piezoelectric bimorph. The validity of analysis method was confirmed by comparing the change of the resonance frequency with thickness and material of bimorph. In addition, we was found that the thicker the thickness of the elastic plate is the higher the resonance frequency. Due to the fact that admittance is not uniform for the thickness, we knew there is the optimal condition for the thickness of elastic plate. Also, in the specific thickness ratio, the electromechanical coupling coefficient is uniform by Young's modulus. Therefore we found that there is a optimal thickness ratio between piezoelectric and elastic plates. From these results, it is expected that the electroacoustic characteristic analysis will be usefully to apply to design factors of piezoelectric bimorph.