Shear-Horizontal Wave Manipulation using Flexural Resonance-based Elastic Metamaterial

Shear-horizontal (SH) waves offer unique advantages for guided wave–based structural health monitoring applications. Their in-plane motion reduces sensitivity to environmental conditions. Additionally, the non-dispersive SH0 mode minimizes signal distortion. This paper employs resonant metamaterials to focus SH_0 waves before detection by a sensor. The objective is to amplify the signal and overcome attenuation of the mode as it propagates through a structure. The results show that flexural resonances of the unit cell modify SH modes and produce polariton-like dispersion behaviors. The dispersion curve for the SH mode through the metamaterial exhibits three distinct regions: non-dispersive, dispersive, and polariton. These regions are then used to design a frequency-selective metamaterial system for SH0 waves in a plate. The results represent the first demonstration of focusing SH0 modes using resonant metamaterials.