Active band gap control of magnetorheological meta-plate using frequency feedback control law

An innovative special class of magnetorheological metamaterial is proposed to achieve a tunable band gap using a new frequency feedback control law. By using the frequency feedback control law, the active band gap can intelligently track the external excitation frequency. The active control function of the band gap is realized using an intelligent local resonator embedded in the plate. Such a local resonator consists of a mass and a magnetorheological elastomer (MRE) driven by an external magnetic field. The local resonator and metamaterial plate are modeled analytically, and an analytical expression is derived to predict the band gap region. The effect of the external magnetic field on vibration attenuations is analyzed by the Galerkin method. Subsequently, a closed-loop frequency feedback control strategy is used to actively adjust the band gap according to the excitation frequency. Based on this frequency feedback control strategy, the effective band gap range of the metamaterial plate can be largely widened. The effect of damping of the MRE on broadband vibration reduction is also investigated, and the results show that the damping of the MRE plays an important role in the control of the band gap of the magnetorheological metamaterial.