首先分析了覆盖冰层的各向同性半无限大弹性体中的声表面波(SAW),求得了声表面波波速与冰层厚度间的关系。结果表明,当冰层厚度为0时,求得的波速与没有冰层覆盖相对应的半无限大弹性体的声表面波波速相同;当冰层厚度不断增加时,求得的声表面波波速趋向于冰层中的波速。随后分析了基体是各向同性无限大弹性板的情况。计算结果表明,由于弹性板与冰层的相互作用,实际振动会出现多个声表面波模态和相应的波速。
Our study starts from analyzing the interaction of a thin ice layer and surface acoustic waves in an isotropic semi-infinite substrate, and the relationship between the surface acoustic wave velocity and the thickness of ice layer has been obtained. The results show that when the thickness of the ice layer is zero, surface acoustic waves will have the same velocity with the corresponding semi-infinite case lwith the increase of the thickness of the ice layer, wave velocity will be similar to the velocity in ice layer. Then the substrate which is an isotropic infinite plastic plate has been analyzed. The numerical calculating results show that there exist many displacement modes and corresponding velocities in the practical vibraion due to the interaction between the plate and ice layer. The theory and method from this study will have practical applications to the analysis of SAW ice sensor for modeling and design.