Abstract:

Reducing the vibration transmission in beams is of significant interest, as beams are among the most widely used basic structures in numerous practical engineering applications. However, achieving broadband suppression of multi-polarization low-frequency vibration in beams presents a challenge. This study proposes a single-phase multi-resonant metabeam, which consists of a host beam with subwavelength arrays of tunable local resonators. These resonators exhibit adjustable multi-polarization resonant modes that strongly couple with the host beam, enabling simultaneous suppression of multi-type waves over a broad frequency range. The theoretical analysis demonstrates that under the fixed total added-mass ratio ({\gamma }_{\text{total}}=1.5), the tailored frequency spacing (\delta =25–50 Hz) and the controlled loss factor (\eta =0.03–0.07) act synergistically to broaden bandgaps through resonant zone overlapping and attenuation peak smoothing. The experimental validation with monolithic three-dimensional (3D)-printed specimens confirms the efficacy of this design in multi-polarization vibration control within a deep-subwavelength bandgap, opening a new avenue for designing multi-polarization vibration suppression structures.

Key words: metastructure, vibration suppression, metabeam, bandgap, multi-polarization