The effect of centrifugal force on the dynamic performance of beam-type rotational energy harvesters

To realize high-efficiency energy harvesting in rotational motion, beam-type piezoelectrical energy harvesters (PEH) have been attracting increasing attention. However, few theoretical models in previous studies could successfully reveal the underlying mechanism of the centrifugal force acting on the PEH. To fill in this gap, a mathematical model considering the installation angle and the rotational radius has been established in a rotational coordinate system to describe the effect of the centrifugal force on the dynamic performance of the beam-type PEH in rotational motion. Based on the proposed model, corresponding theoretical analyses have been conducted to investigate the influence of PEH parameters, including the installation angle and the rotational radius, on the dynamic performance of PEH. Numerical results demonstrate that the installation angle plays a significant role in the effective frequency range and related power generation, as the centrifugal force orientation corresponding to different installation angles has different effects on the movement of the cantilever beam. In addition, experimental results of the forward configuration and the reverse configuration, validate the impact of the centrifugal force on dynamic performances. In summary, this study provides theoretical guidance for the design of the beam-type PEH in rotational motion.