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研究了纵波垂直入射上下基体为同种介质且含有线性粘滞粘接层的三层板状粘接结构时声波的反射和透射特性,基于粘接界面的准静态模型(QSM)并结合各向同性线性粘滞体的本构方程,导出了含有粘滞系数和体积弹性模量的纵波反射和透射系数表达式。首先将纵波的准静态模型解和精确解进行对比,研究了准静态模型的适用条件。其次在界面处于不同接触形式(完好连接和粘滞型弱粘接)的情况下,分别讨论了考虑和不考虑界面相对质量对声反射和透射特性的影响。接着分析了粘滞粘接层参数的变化对纵波反射和透射特性的影响。最后在不大于0.1 MHz-mm的较小频厚积范围内简要阐述了如何鉴别界面形式。结果表明,准静态模型适用于较小频厚积的检测;是否考虑界面的相对质量对纵波的反射和透射特性影响不大;在特定的频厚积下,利用纵波的反射或透射系数方法结合准静态模型可有效辨别界面形式。研究成果可为实验时采用纵波垂直入射检测粘接结构提供一定的理论参考。
The reflection and transmission characteristics of acoustic waves in a three-layer plate-like bonded structure with vertical and vertical incidence of vertical and vertical substrates and a linear viscous bonding layer were studied. Based on the quasi-static model (QSM) The constitutive equations of homosexual linear viscous bodies derive the expressions of the compressional and transmissivity of longitudinal waves with viscous and bulk modulus. First, the quasi-static model and the exact solution of the longitudinal wave are compared, and the applicable conditions of the quasi-static model are studied. Secondly, the influences of interface relative mass on acoustic reflection and transmission properties are discussed separately with different contact forms (intact joints and viscous weak bonds). Then the influence of the change of viscous bonding layer parameters on the reflection and transmission of longitudinal wave is analyzed. Finally, the range of less than 0.1 MHz-mm thick plot of a brief description of how to identify the interface form. The results show that the quasi-static model is suitable for the detection of smaller frequency-thick product. Whether the relative mass of the interface is considered has little effect on the reflection and transmission characteristics of the longitudinal wave. Under certain frequency-thick product, the reflection or transmission coefficient of the longitudinal wave is used Quasi-static model can effectively distinguish the interface form. The research results can provide a theoretical reference for testing the bonding structure by using longitudinal incidence of vertical waves.