Effect of Electromechanical Coupling on Dynamic Characteristics of a Piezoelectric Nonlinear Energy Sink System

Abstract

Integrating a piezoelectric nonlinear energy sink (NES) to a host structure has recently been used to realize simultaneous vibration control and energy harvesting. This paper investigates a piezoelectric NES system connected with a resistive load, revealing the influence of the electromechanical coupling on the nonlinear dynamic phenomena and the consequent energy harvesting performance under impulsive and harmonic excitations. For impulsive excitation, the periodic orbits of the electromechanical system are analysed based on the complexification-averaging method and validated by the wavelet transform of the damped response from numerical simulations. For harmonic excitation, the steady-state response of the displacement and power output can be obtained by the utilization of the Newton-enabled harmonic balance method (NHBM) and numerical simulations. The frequency–energy plot shows the evolution of the backbone branches due to the equivalent electrical stiffness induced by the piezoelectric transducer. Furthermore, for the steady-state response, the influence of the electromechanical coupling on the vibration suppression performance, the harvested power as well as the operational bandwidth are illustrated. In addition to the direct effect on the energy conversion efficiency, the results indicate that the increase of electromechanical coupling will eventually deactivate energy localization phenomenon in the NES for both impulsive and harmonic excitation, which will also affect the energy harvesting performance.