Auto-adaptive Metastructure for Active Tunable Ultra-Low Frequency Vibration Suppression

Metastructures provide a new way to solve the problem of low-frequency vibration suppression because of their unique low-frequency bandgap characteristics. Traditional metastructures usually suffer from the problem of narrow bandgap at low frequencies, which cannot tolerant to uncertainties in manufacturing process of metastructures and cannot adapt to changing working conditions. One way to overcome the shortcomings is to design metastructures with tunable bandgaps. However, it is still a challenge to realize an auto-adaptive metastructure with a highly efficient tunability. In this work, we propose an active metaplate consisting of a host plate and a periodic array of local resonators that can be collectively and actively tuned using stepping motor. We demonstrate numerically and experimentally that the proposed active metaplate can realize continuous tunable ultra-low frequency bandgap. By introducing an auto-adaptive control strategy, it can realize auto-adaptive vibration attenuation at ultra-low frequencies. The proposed active metaplate has promising application prospects since it can achieve real-time active vibration suppression by using only a few active components.