Reflection and refraction of plane waves at the interface of multilayered media

This research article explores the phenomena of the reflection and refraction of plane waves at two interfaces, one of which is the interface between the micropolar elastic solid half-space and viscous liquid layer and another interface between the inviscid liquid half-space and viscous liquid layer. The basic equations of micropolar elastic solids and viscous and inviscid liquids are converted into the xy-plane and solved with the plane harmonic solution method. On the plane interfaces, the primary wave (P-wave) or vertical shear wave (SV-wave) is considered to be an incident wave. The sliding contact parameter-influenced reflected waves in a micropolar elastic solid half-space, and the refracted waves in a viscous liquid layer are derived analytically. In micropolar elastic solids, there are three different kinds of waves named P-wave, SV-wave, and microrotational wave (MR-wave), each with different speeds. P-waves and SV waves are present in viscous liquids, while SV waves are present in inviscid liquid half-spaces. Thickness-influenced amplitude ratios are obtained at the interface boundary between the viscous liquid layer and the inviscid liquid half-space, whereas sliding contact parameter-influenced amplitude ratios are obtained at the interface boundary between the micropolar elastic solid half-space and the viscous liquid layer. The detailed study on the impacts of the sliding contact parameter and the thickness of the viscous liquid layer is presented graphically for a particular model.