A Shape–Memory–Programmable Tuning Fork Metamaterial with Adjustable Vibration Isolation Bands

Honeycomb structures are widely utilized in engineering due to their lightweight, high strength, high stiffness, excellent energy absorption, and outstanding vibration isolation performance. In this study, we propose a novel tuning fork-honeycomb metastructure, which demonstrates excellent tunable vibration isolation capabilities. The geometric configuration of the structure before and after shape memory-induced deformation is described, and a theoretical model for the natural frequency of the initial configuration is established.The vibration isolation performance of the structure is validated through simulations and experiments, and three strategies for tuning its vibrational behavior are proposed: First, by exploiting variable stiffness, shape memory materials are used to achieve a linear shift in the band gap position; at 75 °C, the starting frequency of the band gap decreases to 95% of its value at room temperature; Second, based on shape memory programming, the deformed structure exhibits a 20% reduction in the center frequency of the first band gap and a 47% reduction in the center frequency of the second band gap compared to the undeformed configuration; Finally, by altering the geometry of the tuning fork structure, in-plane deformation is shown to provide superior low-frequency vibration isolation performance compared to out-of-plane deformation.This study, under the combined influence of the shape memory effect and local resonance effect, achieves full-band vibration isolation within the 200-2000 Hz range, offering a novel perspective for designing structures with tunable wide-frequency vibration isolation capabilities.