Research on dual-functional properties of an improved piezoelectric metamaterial beam for simultaneous vibration suppression and energy harvesting

An improved dual-functional piezoelectrical metamaterial beam is constructed to achieve vibration suppression and energy harvesting simultaneously. The local oscillator is created by connecting a shunt inductance circuit to a multilayer piezoelectric patch. In addition, each resonator is linked to an external load resistor, to convert vibration energy into electrical energy. A mathematical model of the vibration control and piezoelectric energy harvesting is developed for the improved piezoelectric metamaterial beam, based on which the vibration reduction and energy harvesting performances of the system are evaluated. The analytical results are then validated using finite element (FE) analysis. The FE simulation results of the vibration control and energy harvesting show good agreements with the counterpart analytical results. Moreover, impedance matching analysis is carried out for the dual-functional performance of the improved piezoelectric metamaterial beam, and the influence of impedance on vibration suppression and energy harvesting performance is obtained. Compared to the conventional piezoelectric metamaterial beam, the improved piezoelectric metamaterial beam can generate a lower frequency resonance bandgap, with the center frequency of the bandgap being depending on the number of piezoelectric patch layers and the stacking mode, and a good power generation performance is achieved in lower frequency bands. Therefore, the dual-functional application of the piezoelectric metamaterial beam is extended to a lower frequency band, with avoiding the disadvantage of conventional piezoelectric metamaterials to reduce the resonant frequency by using large inductance components. Notably, electrical loads for the optimal vibration suppression and energy harvesting performance within the bandgap may require different impedance matching. However, it is found that when the electrical load for the optimal output power within the bandgap is chosen as the design basis, not only can a broadband power generation capacity be realized in the bandgap and the passband under the band-edge effect, but a relatively good vibration suppression performance is observed.