Complete mode conversion between longitudinal and transverse waves by an elastic metamaterial slab with a double-scatterer structure

In this work, we propose a design of a double-scatterer structure to achieve complete conversion for elastic bulk waves. Every unit of the elastic metamaterial slab contains a pair of scatterers with a relatively oblique direction. When the slab attaches on a semi-infinite solid background, it can completely convert the normal incident longitudinal wave into the reflected shear wave, or vice versa. The conversion can be attributed to the in-phase coupling of the double scatterers' quadrupolar resonances. The coupled two quadrupoles could interact with the background and bring oblique displacements. Consequently, the oblique displacements generate horizontal displacements for reflected waves.

Automated summary

In this study, a double-scatterer structure is proposed to achieve complete conversion of elastic bulk waves. Each unit of the elastic metamaterial slab contains a pair of scatterers with a relatively oblique direction. When attached to a semi-infinite solid background, the slab can completely convert the normal incident longitudinal wave into a reflected shear wave, or vice versa. The conversion is attributed to the in-phase coupling of the double scatterers' quadrupolar resonances, resulting in oblique displacements and horizontal displacements for reflected waves.