Magnetism-modulated tunable bandgap for active metamaterial beams integrated with magnetorheological elastomers

The integration of smart materials with external stimuli to tune bandgap properties has garnered significant attention in recent years. Magnetorheological elastomers (MREs) are particularly promising due to their controllable stiffness, which responds rapidly and reversibly to external magnetic fields. This unique property makes MREs an ideal candidate for achieving tunable bandgaps. In this paper, the effects of magnetic modulation on bandgap tuning by designing three types of metamaterial beams integrated with MREs are explored: the Magnetorheological Elastomer Metamaterial Solid Beam, the Magnetorheological Elastomer Metamaterial Hole Beam, and the Magnetorheological Elastomer Metamaterial Embedded Beam. To investigate the bandgap characteristics of these beams under different external magnetic field strengths, both theoretical analysis and the spectral element method are employed. Additionally, finite element analysis is used to study the transmissibility of the beams and to discuss the effects of relevant parameters on their performance. Experimental results are obtained for the three types of MRE-based metamaterial beams and compared with the theoretical and simulation results. This comparison confirmed the magnetic modulation-induced tunable bandgap property and revealed the influence of the straight-band effect. The work provides a comprehensive investigation of bandgap characteristics for MRE-based metamaterial beams under different design models, which not only confirms the capability of magnetic-induced tunable bandgaps but also demonstrates the potential of structural design to achieve a wider bandgap.