Reflection of plane waves from the stress-free boundary of a nonlocal elastic solid half-space containing double porosity

Reflection phenomena of a set of coupled longitudinal waves/shear wave striking obliquely against the mechanically stress-free boundary surface of a uniform nonlocal elastic solid half-space with double porosity structure have been investigated. Employing the appropriate nonlocal stress-free boundary conditions at the surface, the formulae for reflection coefficients and their corresponding energy ratios have been derived for the dissipative and non-dissipative models. Their variations have been computed against the angle of incidence for a specific model. It is found that all the reflection coefficients depend upon the presence of the nonlocality, porosities of both types, frequency and angle of incidence. Their impact on various coefficients is also studied numerically and depicted graphically.

Automated summary

The reflection phenomena of a set of coupled longitudinal waves/shear wave striking obliquely against the mechanically stress-free boundary surface of a uniform nonlocal elastic solid half-space with double porosity structure are investigated. The formulae for reflection coefficients and their corresponding energy ratios are derived for both the dissipative and non-dissipative models by employing appropriate nonlocal stress-free boundary conditions at the surface. The variations of these coefficients with the angle of incidence are computed for a specific model. It is found that the presence of nonlocality, porosities of both types, frequency, and angle of incidence all affect the reflection coefficients.