有液层负载时薄板中类Lamb波的传播

The propagation of Lamb waves in a plate bordered with liquid layers

本文研究薄板一面有液层负载时板中类Ｌａｍｂ波的传播，从弹性波传播理论出发，导得了类Ｌａｍｂ波的色散方程。由于几何不对称，因此不可能严格区分出对称与反对称模式，而是耦合在一起。数值计算结果表明，板中类Ｌａｍｂ波相速度随液层厚度增加呈周期变化。当ｋｔｄ＜＜１时类反对称模式的相速度变化近似与液层厚度成正比，这与特征阻抗法结果相同。初步实验结果验证了上述理论。

Based on the general theory of elasticity, a dispersion equation for thin plate bordered withliquid layers is derived. FOr the case of one liquid layer, numerical calculations show that the phasevelocity changes periodically with the thinness of liquid layer. When kid << 1, phase velocity of Ac modedecreases linearly with the increase of liquid loading, which is most interesting in acoustic sensing.