Tunable multi-metamaterials intergrated with auxiliary magnetorheological resonators

Abstract

In recent years, there has been a surge in interest in utilizing multi-metamaterials for various purposes, such as vibration control, noise reduction, and wave manipulation. To enhance their performance and tunability, auxiliary resonators and magnetorheological elastomers (MREs) can be effectively integrated into these structures. This research aims to formulate the wave propagation analysis of periodic architected structures integrated with MRE-based auxiliary resonators. For this purpose, cantilever MRE beams are embedded into conventional unit cells of square and hexagonal shapes. Integrating MREs into multi-metamaterial structures allows for real-time tuning of the material properties, which enables the multi-metamaterial to adapt dynamically to changing conditions. The wave propagation in the proposed architected structures is analyzed using the finite element method and Bloch’s theorem. The studied low-frequency region is significant, and the addition of MRE resonators leads to the formation of a mixture of locally resonant and Bragg-type stop bands, whereas the basic structures (pure square and hexagonal) do not exhibit any specific band gaps in the considered region. The effect of different volume fractions and applied magnetic fields on the wave-attenuation performance is also analyzed. It is shown that band gaps depend on the material parameters of the resonators as well as the applied magnetic flux stimuli. Moreover, the area of band gaps changes, and their operating frequency increases by increasing the magnetic flux around the periodic structure, allowing for the tuning of wave propagation areas and filtering regions using external magnetic fields. The findings of this study could serve as a foundation for designing tunable elastic/acoustic metamaterials using MRE resonators that can filter waves in predefined frequency ranges.