基于流固耦合理论,采用有限元方法,建立压电激发理想流体中各向异性板的泄漏Lamb波的数值模型.数值模拟研究单向纤维增强复合材料中的泄漏Lamb波的色散和衰减特征,得到了全波场数值解,进而分析了不同激励频率,不同纤维取向对波形的影响.结果表明:理想流体中各向异性板的泄漏Lamb波可存在非色散,衰减较小的So模态和色散,衰减较大的Ao模态;通过选择激励频率可以选择合适的传播模态.材料纤维取向不同会影响泄漏波形的传播速度以及色散和衰减特性.数值模拟建立了激励源、材料参数以及相应波形之间的定量关系,可为泄漏Lamb波技术应用于NDE和NDT提供理论参考.%Based on the fluid-structure interaction theory, finite element method was used to numerically simulate the Leaky Lamb waves derived from piezoelectric wafer active sensor of anisotropic plate in ideal fluid. The dispersion and attenuation characteristics of Leaky Lamb waves in unidirectional fiber reinforced composites were analyzed to obtain the numerical solution of full wave field. The effects of different orientation of fiber with different excitative frequencies on the waveform were discussed. The results show that two modes of Leaky Lamb waves exist simultaneously in anisotropic plate immersed in ideal fluid. One is a Non-dispersive and barely attenuation mode of S0 , the other is a dispersive and attenuation mode of A0. Velocity, dispersion and attenuation characteristics of waveform are significantly affected by fiber orientation. The quantitative relation between the excitation, the material parameters and the corresponding waveform was established by numerical simulation to provide a theoretical basis for NET and NDE applications of Leaky Lamb waves.
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