Vibration Suppression and Energy Harvesting of Two Degree of Freedom Main Structure Coupled with a Bistable Nonlinear Energy Sink Under Transient Excitation

The nonlinear energy sink (NES) device based on the bistable mechanism and piezoelectric effect (PBNES) can effectively enhance its vibration suppression and energy harvesting performance thanks to the significant inter-well motion and lower excitation threshold requirements.

In this work, the dimensionless electromechanical-coupled governing equations of a two-degree-of-freedom main structure coupled with PBNES under transient excitation are numerically and analytically explored.

The vibration suppression and energy harvesting performance of PBNES on a two-degree-of-freedom main structure are investigated from three different perspectives: energy dissipation and transfer, time-frequency response, and reduced slow flow, respectively.

The results suggest that the energy dissipation and harvesting performance of PBNES is superior to that of NES device based on the monostable mechanism and piezoelectric effect (PMNES) within various excitation intensity ranges. The PBNES oscillator undergoes inter-well and intra-well motions successively, and the vibration amplitude of the main structure is significantly suppressed. The energy transfer mechanisms between PBNES and the main structure are mainly realized through 1:1:1 transient resonance capture (TRC) with the first natural frequency, as well as the subharmonic and superharmonic TRC. The vibration amplitude of the main structure is effectively suppressed when phase locking occurs between the PBNES and the main structure.