Nonlinear analysis and response identification of tristable energy harvesters under wind and base excitations

The excellent working performance of nonlinear vortex-induced vibration (VIV) energy harvesters has been verified by researchers. However, in practical working environments, the harvester is not only affected by wind excitation but also by base excitation. Analyzing the impact mechanism of base excitation on the nonlinear harvesters' working performance is very important for designing wind energy harvesters with high energy harvesting efficiency and strong robustness. This paper designs a VIV energy harvester based on the tristable structure, and the frequency spectrum, Poincaré maps, and phase diagrams are adopted to characterize the harvester's output response and dynamic characteristics. It is found that base excitation can adjust the working performance of the harvester. In addition, the complex response characteristics (chaotic, periodic and quasi-periodic responses) of the harvester is accurately identified by the analysis method of “0–1” test, and the parameter analysis are carried out. Overall, this paper provides theoretical framework for analyzing tristable VIV energy harvesters subjected to complex excitations.