Analysis and testing on the vibration mode of a metallic hemispher ical shell excited piezoelectr ically

本文研究壓電激發與感測之金屬半球殼 的振動分析與量測。考慮半球殼材料為均質及 等向性，外圍再貼上壓電材料作為感測與驅動 機構，以Niordson 的薄殼理論為基礎，採用 Love-Kirchhoff 的薄殼假設，先以能量法推導 均質非等向性壓電薄殼的組成方程式，再以漢 彌頓原理處理此機電偶合系統，求得旋轉壓電 與金屬半球殼的振動分析與量測。考慮半球殼 運動方程式。.討論自由振動球殼的自然頻率 和模態。就強迫式激發的球殼，推導其位移運 動方程式並就舉出模態之振動波形加以解 釋，利用有限元素分析軟體模擬球殼在自由振 動下的各模態振動情形。 實驗以壓電激發與感測由球殼的模態測 試，得半球殼的自然頻率及振動模態。This paper considers the vibration mode of a metallic hemispherical shell excited piezoelectrically. Constitutive equations for a thin piezoceramic shell with thickness polarization and electro-covered faces are derived using Niordson’s shell theory. Coupled electromechanical equations of motion, describing the dynamics of the vibrating hemispherical shell, are derived using Hemilton’s principle, Rayleigh’s solution of the shell and Rayleigh-Ritz methods. Vibration modes and natural frequencies of the hemispherical shell are numerically calculated and measured