Bio-inspired branch structure seismic metamaterial: attenuating low-frequency Rayleigh waves

Abstract This study investigates the transmission characteristics of natural forests with branches and introduces a bio-inspired branch structure seismic metamaterial designed to create bandgaps for low-frequency Rayleigh waves. Employing the finite element method, we reveal the mechanism behind the generation of these Rayleigh wave bandgaps and their transmission properties. A distinct 'collectivization mode' within the bio-inspired branch structure seismic metamaterial is identified, effectively attenuating Rayleigh waves. A collectivization coefficient is introduced for quantitative characterization, and we extend the analysis to multi-layered soil mediums, demonstrating an interface with the metamaterial's bandgaps. Frequency-domain analysis highlights the difference between using the collectivization mode and traditional methods for attenuating surface waves, offering a novel approach to low-frequency Rayleigh wave reduction with implications in seismology and related fields.