Purpose

The purpose of this study is to investigate the reflection of plane waves in a double-porosity (DP) thermoelastic medium.

Design/methodology/approach

To derive the theoretical formulas for elastic wave propagation velocities through the potential decomposition of wave-governing equations. The boundary conditions have been designed to incorporate the unique characteristics of the surface pores, whether they are open or sealed. This approach provides a more accurate and realistic mathematical interpretation of the situation that would be encountered in the field. The reflection coefficients are obtained through a linear system of equations, which is solved using the Gauss elimination method.

Findings

The solutions obtained from the governing equations reveal the presence of five inhomogeneous plane waves, consisting of four coupled longitudinal waves and a single transverse wave. The energy ratios of reflected waves are determined for both open and sealed pores on the stress-free, the thermally insulated surface of DP thermoelastic medium. In addition, the energy ratios are compared for the cases of a DP medium and a DP thermoelastic medium.

Originality/value

A numerical example is considered to investigate the effect of fluid type in inclusions, temperature and inhomogeneity on phase velocities and attenuation coefficients as a function of frequency. Finally, a sensitivity analysis is performed graphically to observe the effect of the various parameters on propagation characteristics, such as propagation/attenuation directions, phase shifts and energy ratios as a function of incident direction in double-porosity thermoelasticity medium.

中文翻译：

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双孔隙热弹性介质中的非均匀波传播

目的

本研究的目的是研究平面波在双孔隙（DP）热弹性介质中的反射。

设计/方法论/途径

通过波控方程的势分解推导弹性波传播速度的理论公式。边界条件的设计考虑了表面孔隙的独特特征，无论它们是开放的还是密封的。这种方法为现场遇到的情况提供了更准确、更现实的数学解释。反射系数通过线性方程组获得，并使用高斯消元法求解。

发现

从控制方程获得的解揭示了存在五个不均匀平面波，由四个耦合纵波和单个横波组成。确定了 DP 热弹性介质的无应力隔热表面上的开放孔和密封孔的反射波能量比。此外，还比较了DP介质和DP热弹性介质情况下的能量比。

原创性/价值

通过数值示例来研究夹杂物中的流体类型、温度和不均匀性对相速度和衰减系数（作为频率的函数）的影响。最后，以图形方式进行灵敏度分析，以观察各种参数对传播特性的影响，例如双孔隙热弹性介质中的传播/衰减方向、相移和能量比作为入射方向的函数。