Exploring nonlinear degradation benefit of bio-inspired oscillator for engineering applications

Nonlinear structure design is an indispensable link in the development of vibration isolation, energy harvesting and fault diagnosis technologies. It is also one of the most effective technical means to improve the performance of structures in engineering applications. In this study, a bio-inspired nonlinear oscillator is proposed and the benefits of nonlinear degradation in engineering applications are explored. First, the degradation bistable oscillator and high-order quasi-zero stiffness oscillator can be obtained after the degradation of the bio-inspired nonlinear oscillator. Through the amplitude-frequency analysis, it is found that the nonlinear degradation can reduce the unstable solution in the ultra-low frequency region and reduce the resonant frequency of the bio-inspired nonlinear oscillator. Therefore, the degeneration nonlinear oscillator can realize the large-amplitude inter-well motion at ultra-low frequency or low random excitation intensity. Secondly, the theory and method of vibration isolation and energy harvesting based on the nonlinear degradation mechanism are proposed, and the vibration isolation and energy harvesting performance of the oscillator under harmonic and stochastic excitations are analyzed. Finally, the use of the stochastic resonance of the degeneration bistable oscillator can greatly improve the signal-to-noise ratio, enhance the weak fault signal, and realize early fault diagnosis. The related results help to deepen the understanding of nonlinear degenerate systems and provide new technical approaches for engineering applications.