The Study on Piezo-Disk Ultrasonic Transducer : Theoretical Analyses and Experiment Verification

• Main Authors: Chia-ChungSung, 宋家仲
• Other Authors: Szu-Chi Tien
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/34437267820722473773

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 98 === The main purpose of this research is to present a way of mathematical model to predict the vibrating behavior of thickness-electroded piezoelectric disks as ultrasonic transducers. Theoretical model was derived for steady state vibration of piezoelectric disks. When thickness and diameter are comparable in dimension, coupled vibration of thickness and radial motion is considered. Spectrum of displacement at the surface in the thickness direction was simulated with specific boundary conditions to analyze the resonance frequency. And the sound field radiation( pressure wave) in near field produced by the vibration of the piezoelectric disk was evaluated by Huygens-Fresnel principle. Disk vibration and the resulted sound pressure were measured by a set of home-made laser position sensor and a pressure sensor, respectively. It was found that the intensity of sound wave was enhanced because of its continuous reflection between the disk and pressure sensor. Based on experiment results, the validity of coupled vibration model and Huygens-Fresnel principle was verified.