本論文有系統的建立壓電能量擷取系統的特性探討,文中應用壓電陶瓷雙晶片與壓電纖維複合雙晶片以不同極化方向堆疊及電極連接模式,產生不同的三維振動耦合特性與探討其激發電能的效果。本文利用多種不同的實驗技術搭配有限元素法的數值計算結果,在不同電極條件下的面內與面外振動特性作深入且完整的研究。 實驗量測使用多種方法進行分析,包括全域式的電子斑點干涉術可同時針對壓電材料的面內與面外的模態振形與共振頻率進行即時量測,並記錄激振電壓可作為三維振動效率的參考依據;雷射都卜勒振動儀可應用動態系統針對壓電材料單點的面外振動進行穩態掃頻量測,並利用脈衝訊號激發的暫態量測訊號進行時頻轉換,兩種量測方式皆可獲得壓電材料的面外共振頻率;阻抗分析儀則針對壓電材料的電性作量測並可獲得面內振動的共振頻率,同時亦可獲得反共振頻率;光纖位移計可量測面外位移量與頻率的關係;將聚偏二氟乙烯薄膜感測器貼附在壓電試片上並且配合電荷放大器量測壓電材料的共振頻率。所有實驗量測結果皆與有限元素數值計算進行分析比較。對於壓電材料的動態特性有了詳細的了解後,再輸入不同的電壓和頻率給振動器並激振壓電試片,擷取壓電材料因為正壓電效應而產生的電流,並接上發光二極體配合光功率計量測其光強度變化。本研究成果呈現壓電材料的三維動態特性於實驗量測與數值計算皆達到相當優異的一致性,本文成果在學術研究領域或工業界的實際應用皆有所貢獻,提供了壓電材料完整的振動資訊並應用於能量擷取系統。
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.