Magnetorheological intelligent chiral metamaterials with ultra-low frequency bandgap

Ultra-low broadband vibrations widely exist in the fields varies from earthquake engineering, aerospace, to precision instruments and control systems, while effectively controlling them remains a challenge due to the slow attenuation of long-wavelength vibrations. In this study, a novel magnetorheological intelligent metamaterial (MIM) is proposed to address this problem. The MIM vibration isolating system consists of magnetorheological elastomers (MRE) chiral compression-torsion coupling structure with an electromagnetic coil. Based on the lumped mass method, the theoretical analysis model of the frequency response function is established to reveal the vibration characteristics and dispersion relation of the MIM. The ultra-low broadband vibration isolation ability (29.38–53.08 Hz) is observed owing to the mutual cancellation of elastic wave polarization in the original chiral structure. The magnetic field is adjusted by the input current of the electromagnetic coil, and the bandgap tunable performance of MIM is obtained. The theoretical analysis, simulation and experimental results have demonstrated that the MIM exhibits ultra-low broadband vibration isolation performance. The chirality design and compression-torsion coupling magnetorheological metamaterial may provide a novel idea and method for further investigation on intelligent metamaterials, especially in the field of tunable ultra-low broadband vibration manipulation.