The Effects of Fluid Boundary Conditions on the Dispersion Relations of Guided Waves Propagating in Piezoelectric Plates

壓電材料板在單面流體層負載下蘭姆波的波傳行為之頻散關係探討

楊哲化(Che-Hua Yang) ； 吳佳翰(Chia-Han Wu)

《中華民國振動與噪音工程學會論文集》 2008 (2008/05) Pp. 96-98

https://doi.org/10.30028/CSSVANNUAL.200805.0096

摘要

本研究主要在利用理論及實驗的方法探討壓電材料板在單面流體層負載下蘭姆波的波傳行為之頻散關係。理論部份將利用遞迴近似勁度矩陣法(recursive asymptotic stiffness matrix method, RASM)，模擬壓電 材料板在單面流體層負載下蘭姆波的波傳行為。實驗部分則利用雷射超音波技術(Laser ultrasound technique, LUT)作為量測導波頻散關係的方法。研究結果可發現，實驗量測的頻散關係與理論模型計算的頻散關係相當符合。研究中並發現當改變流體層的厚度、密度、導電度及介電係數時，對其頻散曲線有明顯的偏移現象。未來可提供發展超音波量測流體性質感測器的重要依據。

關鍵字

遞迴近似勁度矩陣法 ； 蘭姆波 ； 雷射超音波技術 ； 頻散關係

並列摘要

This study is focused in the measurement and modeling for the dispersion relations of Lamb waves propagating in different boundary conditions of LiNbO3 plates. The theoretical model based on a recursive asymptotic stiffness matrix method (RASM)[5] is used to provide numerical calculations. A hybrid laser-generation/laser- detection technique is used to measure the dispersion relations. Three kinds of fluid loading condition are considered for two sides of the plate, namely vacuum-vacuum (V/V), fluid-vacuum (F/V) and fluid/fluid (F/F) conditions. In RASM method, this study is used the elastic body to simulate the water as the same density, wave velocity and the Poisson ratio is very close to 0.5 or the shear modular very close to zero.

並列關鍵字

RASM ； Lame waves ； laser ultrasonics