Nonlinear magnetic force coupled piezoelectric cantilever beam-spring pendulum for multi-directional vibration energy harvesting

Abstract

Harvesting energy from environmental vibrations to power devices such as wireless sensors holds significant potential. Given the multi-directional nature of environmental vibration energy, this study introduces a piezoelectric cantilever beam-spring pendulum system influenced by nonlinear magnetic forces. The structure is influenced by both internal energy exchange and nonlinear magnetic interactions between magnets. The magnetic energy equations are established through the magnetic dipole model and combined with the energy equations of the structure to derive the governing equations utilizing the Lagrange's equations. The corresponding modelling analyses and numerical simulations demonstrate that, under appropriate parameter configurations, the interplay between internal energy exchange and nonlinear magnetic forces achieves a significant enhancement effect. Compared to other structures, the bandwidth of the proposed structure can be increased up to 115.98 % under x-direction excitation. The maximum RMS voltage can be improved up to 151.83 % under z-direction.