On the Use of Piezoelectric Nonlinear Energy Sink for Vibration Isolation and Energy Harvesting

Nonlinear energy sink (NES) is employed to passively reduce vibration transmission in this study. A two-degree-of-freedom system, comprising a primary structure coupled with a grounded piezoelectric NES possessing essential nonlinearity, is investigated for both harmonic force excitation and base excitation. The piezoelectric NES acts as not only a vibration isolator but also an energy harvester when connected to an alternating current circuit. Approximate analysis is carried out by the harmonic balance method and validated by numerical solutions using ODE45 in Matlab and equivalent circuit simulation. The effectiveness of the nonlinear vibration isolation system is evaluated by the force (displacement) transmissibility defined as the root-mean-square ratio of transmitted force (displacement) to the excitation force (displacement), which is compared with that of its linear counterparts. Output voltage of the piezoelectric transducer is also derived. By and large, it is found that the piezoelectric NES could reduce the force (displacement) transmissibility while collecting electric energy efficiently in a relatively broad frequency range.