Nonlinear analysis and power improvement of broadband low-frequency piezomagnetoelastic energy harvesters

Abstract

A significant impediment to the deployment of vibration-based energy harvesting devices has been the limitation of most low-frequency transducers, usually in the form of unimorph or bimorph cantilever beam, to extract energy from a very narrow bandwidth around the transducer's fundamental frequency. In such devices, a slight deviation from the fundamental frequency causes a significant reduction in the level of harvested power by several orders of magnitudes. Additionally, most of the current research efforts on the design of piezoelectric energy harvesters have had limited success in achieving low resonance frequency. To overcome these challenges, we introduce an enhanced broadband low-frequency piezomagnetoelastic energy harvester. This harvester consists of a partially covered piezoelectric cantilever beam with a fixed magnet mass at the top of the magnet tip mass. A nonlinear distributed-parameter model based on Euler-Bernoulli beam theory and Galerkin discretization is developed. This electromechanical model is validated with previous experimental measurements for a specific value of the spacing distance between the two magnets. A parametric study is performed to determine the effects of the spacing distance between the two magnets on the A. Abdelkefi (B) static position of the harvester, natural frequency, and level of the harvested power. It is demonstrated that a decrease between the two attractive magnets results in a decrease in the natural frequency of the harvester with a strong softening behavior which gives the opportunity to harvest energy at broadband low-frequency range. The results also show that the presence and importance of the softening behavior depends on the electrical load resistance. In conclusion, the results show that depending on the available low excitation frequency, an enhanced piezoelectric energy harvester can be tuned and optimized by changing the spacing distance between the two tip magnets.

Design optimization and test for a pendulum suspension of the crop sprayer boom in dynamic conditions based on a six DOF motion simulator

“…During the process of pesticide application in the field, it may be subjected to external incentives from the spray vehicle rolling, water tank sloshing and engine vibration and easy to stimulate low order modes of deformation of the spray boom. Besides, when the natural frequency of boom is consistent with the natural frequency of the pendulum suspension, resonating create the enormous destruction [19] , so spray boom should be treated as a flexible body in the multi-body dynamics modeling process.…”

“…The Opt LHD minimize the integrated mean squared error and maximize the entropy [19] . The Opt LHD sampling improves the LHD in aspect of uniformity and stability.…”

The Effect of Axial Displacement of Magnets in Piezoelectric Energy Harvester

“…The manifestation of magnetic nonlinearities in the energy harvester primarily results in changing the softening and hardening behaviour of the piezoelectric cantilever. However, most research studies concentrate only on one direction of spacing distance where the natural resonant frequency of the energy harvester and thus its performance may not significantly affected [13,14]. In this study, the significance of axial spacing displacement in terms of x-axis (horizontal) and z-axis (vertical) between two repulsive magnets on the resonant frequency and harvester's performance will be discussed.…”

Experimental Study and Parameter Optimization of a Magnetic Coupled Piezoelectric Energy Harvester

“…Tang established a lumped parameter model for the nonlinear piezomagnetoelastic harvester. Abdelkefi et al [33] established a distributed parameter model, which was compared with Tang's lumped parameter model, but still mainly discussed the fixed magnet structure, and did not further analyze the structure of Tang. Yuan et al [34] applied the harmonic balance method with alternating frequency/time domain progress to predict steady-state responses of nonlinear piezoelectric mechanical systems, and Tang's model was used as an example to verify the feasibility of the Another representative method is the 'Multi-Stable Method', and the nonlinear stiffness is introduced by magnetic force to generate various steady states [23,24].…”