Discussion on Dynamic Characteristics and Application of Energy Harvesting of Piezoelectric Fiber Composite Bimorphs and Piezoceramic Bimorphs

• Main Authors: Kuo-Shun Tseng, 曾國舜
• Other Authors: Chien-Ching Ma
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/30823593554869486024

碩士 === 國立臺灣大學 === 機械工程學研究所 === 100 === The energy harvesting systems of piezoelectric material are investigated in this study. The piezoelectric materials, which include piezoceramic bimorphs and piezoelectric fiber composites bimorphs (PFCB), are used to perform experimental measurements and finite element method (FEM) is used to study the out-of-plane and in-plane vibration characteristics. The experimental results of vibration characteristics are verified with numerical calculations. Multilayer piezoelectric component is composited of the same and opposite poling direction, and it has different vibration characteristics by series and parallel electrically connection. This study thoroughly analyse three-dimentsional dynamic characteriscs of piezoelectric materials by experimental measurements and numerical calculations. Several experimental techniques are used to measure the dynamic characteristics of piezoelectric materials. First, the full-filed optical technique, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI), can measure simultaneously the resonant frequencies and mode shapes for in-plane and out-of-plane vibration. The excited voltages needed for different mode shapes are refered to the efficiency of resonant vibration. Second, the pointwise measurement system, laser Doppler vibrometer (LDV), can obtain resonant frequencies not only by dynamic signal swept-sine analysis, but also by the time-frequency transform from impulse signal excitation. Third, the correspondent in-plane resonant frequencies and anti-resonant frequencies are obtained by impedance analysis. Fourth, fotonic sensor (FS) is used to measure the resonant frequencies for out-of-plane modes. Fifth, polyvinylidene fluoride (PVDF) is also used to measure the resonant frequencies. All the results of the experimental measurements are compared with the FEM results. After the dynamic characteristics of piezoelectric materials are analyzed, we use shaker to excite the piezoelectric materials to generate the electric voltage and to light up the LED. It has excellent consistence of resonant frequencies, mode shapes, and normalized displacements on the vibration motion by experimental measurements and finite element numerical calculations.