205 / 2021-03-31 22:19:41

Design, modeling and experiment of a magnetic coupling bistable energy harvester using geometrically nonlinear boundaries for rotating energy harvesting

Rotational energy harvesting,Magnetic coupling,Bistable,Geometrically nonlinear boundaries

Rotating energy is one of the most abundant energy in the ambient environment. Wheel and rotating machinery can directly produce rotation motion, and energy such as wind, wave, human motion and vibration can also be indirectly converted into rotating energy. The rotating energy has the characteristics of high energy density, wide distribution, easy to obtain and convert. The transformation of dissipative rotating energy into electric energy can not only solve the issues caused by the limited life, leakage and unreasonable recovery management of chemical batteries, but also realize the self-powered health monitoring of mechanical equipment, exhibiting the merits of flexibility, environment-friendly and sustainable. This paper presents a magnetic coupling nonlinear bistable rotating energy harvesting system, which can effectively harvest rotating energy in a wide frequency domain, especially in low frequency excitation. The magnetic coupling bistable mechanism can increase the displacement of cantilever beam, and the symmetric nonlinear geometric boundaries can limit the maximum displacement of cantilever beam. The reliability of cantilever beam is guaranteed while increasing the deformation and frequency of cantilever beam. The electromechanical coupling dynamic model of the system is established. The effects of centrifugal softening and centrifugal stiffening on the electrical output of the system are compared. The theoretical and experimental results show that the centrifugal softening effect can increase the displacement of cantilever beam that improve the electrical output performance under low frequency excitation. The centrifugal stiffening effect renders the system harvest energy effectively in a wide frequency range. The proposed rotating energy harvesting system extends the potential application of self-powered sensors in rotor system health monitoring.