Abstract

Rayleigh – Lamb wave propagation in a heterogeneous medium containing an upper sandy layer in a perfect contact with isotropic elastic substrate is analyzed by applying the modified Cauchy sextic formalism. It is also proved that sandy material is essentially anisotropic and should be modeled as an anisotropic material with the cubic symmetry. The performed numerical analysis revealed essential peculiarities with respect to dispersion of Rayleigh – Lamb waves. The observed discrepancy in dispersion portraits of media with sandy layer and with isotropic layer, may be important for the nondestructive evaluation of presence sandy layers in the upper Earth crust.

摘要

Rayleigh – Lamb 波在含有上砂层且与各向同性弹性基底完美接触的非均质介质中的传播通过应用改进的 Cauchy 六分法进行分析。还证明了砂质材料本质上是各向异性的，应建模为具有立方对称性的各向异性材料。所进行的数值分析揭示了瑞利-兰姆波色散的基本特性。观察到的含砂层和各向同性层介质弥散图的差异可能对无损评估上地壳中砂层的存在具有重要意义。