A magnetostrictive tri-stable energy harvester utilizing a shared pre-magnetization field and analysis of its centrifugal effect

Abstract

Energy harvesting technology is an effective solution for passive power supply for structural health monitoring of rotating components. The group found that the tip magnetic mass block can enhance the pre-magnetized magnetic field and interact with the pre-magnetized magnet to form a symmetric tri-stable structure and present asymmetric potential energy trap characteristics. Based on this, this paper presents a magnetostrictive tri-stable rotational energy harvester with a shared pre-magnetization field for the first time. In addition, the influence of the centrifugal effect on the equivalent stiffness of a rotating cantilever beam in a nonlinear tri-stable system cannot be neglected. Still, there is a lack of relevant theories. In this paper, a dynamic model describing the influence of the centrifugal effect on the asymmetric force characteristics of the tri-stable structure is established, and the role of parameters such as installation angle and radius on the dynamic behavior of the cantilever beam is analyzed in depth. Theory and experiments show that adjusting the parameters of the tip magnetic mass block can improve the energy harvesting efficiency and broaden the frequency bandwidth of the tri-stable structure. The installation angle and radius significantly affect the system's adequate frequency bandwidth and harvesting capability. The research results provide a new solution for designing the tri-stable energy harvesting system and important theoretical guidance for optimizing the magnetostrictive rotational energy harvesting system.