scholarly journals Study on Dynamic Snap-Through and Nonlinear Vibrations of an Energy Harvester Based on an Asymmetric Bistable Composite Laminated Shell

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2405
Author(s):  
Ting Dong ◽  
Xinhua Chen ◽  
Jun Zhang

Bistable energy harvesters have been extensively studied. However, theoretical research on the dynamics of bistable energy harvesters based on asymmetric bistable composite laminated plate and shell structures has not been conducted. In this paper, a theoretical model on the dynamics of an energy harvester based on an asymmetric bistable composite laminated shell is established. The dynamic snap-through, the nonlinear vibrations and the voltage output with two potential wells of the bistable energy harvester are studied. The influence of the amplitude and the frequency for the base excitation on the bistable energy harvester is studied. When the frequency for the base excitation with a suitable amplitude in the frequency sweeping is located in a specific range or the amplitude for the base excitation with a suitable frequency in the amplitude sweeping is located in a specific range, the large-amplitude dynamic snap-through, nonlinear vibrations and voltage output with two potential wells can be found to occur. The amplitude and the frequency for the base excitation interact on each other for the specific amplitude or frequency range which migrates due to the softening nonlinearity. The vibration in the process of the dynamic snap-through behaves as the chaotic vibration. The nonlinear vibrations of the bistable system behave as the periodic vibration, the quasi-periodic vibration and the chaotic vibration. This study provides a theoretical reference for the design of energy harvesters based on asymmetric bistable composite laminated plate and shell structures.

2021 ◽  
Vol 13 (5) ◽  
pp. 2865 ◽  
Author(s):  
Sungryong Bae ◽  
Pilkee Kim

In this study, optimization of the external load resistance of a piezoelectric bistable energy harvester was performed for primary harmonic (period-1T) and subharmonic (period-3T) interwell motions. The analytical expression of the optimal load resistance was derived, based on the spectral analyses of the interwell motions, and evaluated. The analytical results are in excellent agreement with the numerical ones. A parametric study shows that the optimal load resistance depended on the forcing frequency, but not the intensity of the ambient vibration. Additionally, it was found that the optimal resistance for the period-3T interwell motion tended to be approximately three times larger than that for the period-1T interwell motion, which means that the optimal resistance was directly affected by the oscillation frequency (or oscillation period) of the motion rather than the forcing frequency. For broadband energy harvesting applications, the subharmonic interwell motion is also useful, in addition to the primary harmonic interwell motion. In designing such piezoelectric bistable energy harvesters, the frequency dependency of the optimal load resistance should be considered properly depending on ambient vibrations.


Author(s):  
Onur Bilgen ◽  
S. Faruque Ali ◽  
Michael I. Friswell ◽  
Grzegorz Litak ◽  
Marc de Angelis

An inverted cantilevered beam vibration energy harvester with a tip mass is evaluated for its electromechanical efficiency and power output capacity in the presence of pure harmonic, pure random and various combinations of harmonic and random base excitation cases. The energy harvester employs a composite piezoelectric material device that is bonded near the root of the beam. The tip mass is used to introduce non-linearity to the system by inducing buckling in some configurations and avoiding it in others. The system dynamics include multiple solutions and jumps between the potential wells, and these are exploited in the harvesting device. This configuration exploits the non-linear properties of the system using base excitation in conjunction with the tip mass at the end of the beam. Such nonlinear device has the potential to work well when the input excitation does not have a dominant harmonic component at a fixed frequency. The paper presents an extensive experimental analysis, results and interesting conclusions derived directly from the experiments supported by numerical simulations.


Author(s):  
Shitong Fang ◽  
Wei-Hsin Liao

Impulsive energy provides a promising source for energy harvesting techniques due to their high amplitude and abundance in a living environment. The sensitivity to excitation of bistable energy harvesters makes them feasible for impulsive-type events. In this paper, a novel impulsively-excited bistable energy harvester with rotary structure and plectrum is proposed to achieve plucking-based frequency up-conversion. The input excitation is converted to plucking force on the bistable energy harvester, so as to help it go into the high-energy orbit. The piezoelectric and electromagnetic transduction mechanisms are combined by incorporating a coil to the structure in order to overcome the increase of damping introduced by the bistable configuration. As a result, high-energy output and broadband performance could be realized. Impact mechanics is employed to develop a comprehensive model, which could be used to analyze the nonlinear dynamics and predict the system responses under various plucking velocities and overlap lengths. Numerical simulation shows that the bistable energy harvester could experience large-amplitude oscillation under impulsive excitation and the hybrid configuration outperforms the standalone ones under high damping ratio and low coupling coefficient. The proposed design is targeted to be applied on the turnstile gates of the subway station. Less human effort would be needed when passengers pass the turnstile gate due to the snap-through motion of bistability.


Author(s):  
Ambrish P. Patel ◽  
Adam M. Wickenheiser

Traditionally, vibration-based energy harvesters have been designed for specific base excitation frequencies by matching their natural frequencies. However, harvesting energy from common human motions is challenging because the low frequencies involved are incompatible with small, light-weight transducers, which have much higher natural frequencies. By using the frequency up-conversion method, a vibration-based, nonlinear, magnetically excited energy harvester exhibits efficient, broadband, frequency-independent performance. A complete model is provided for an energy harvester utilizing the frequency up-conversion method that defines the relationship between the enclosure excitation, the base excitation and the stationary magnets, where the base of the beam is mounted elastically inside an enclosure. The average power output of a vibration-based energy harvester with frequency up-conversion is analyzed using artificial and naturally occurring base excitations such as sinusoidal and walking motions, respectively. Simulations are provided to demonstrate the broadband capabilities of vibration-based energy harvesters with frequency up-conversion, especially for driving frequencies lower than the fundamental frequency, where significant increase in power output are observed when utilizing frequency up-conversion. In addition, the advantages and limitations of approximating a range of natural base excitations with a set of orthogonal basis functions are explored, which provides motivation for Wavelets Analysis. Finally, a procedure is proposed to determine the maximum expected power output.


2021 ◽  
Author(s):  
Anitha Karthikeyan ◽  
Arthanari Ramesh ◽  
Irene Moroz ◽  
Prakash Duraisamy ◽  
Karthikeyan Rajagopal

Abstract Vibrational energy harvesters can exhibit complex nonlinear behavior when exposed to external excitations. Depending on the number of stable equilibriums the energy harvesters are defined and analyzed. In this work we focus on the bistable energy harvester with two energy wells. Though there have been earlier discussions on such harvesters, all these works focus on periodic excitations. Hence, we are focusing our analysis on both periodic and quasiperiodic forced bistable energy harvester. Various dynamical properties are explored, and the bifurcation plots of the periodically excited harvester shows coexisting hidden attractors. To investigate the collective behavior of the harvesters, we mathematically constructed a two-dimensional lattice array of the harvesters. A non-local coupling is considered, and we could show the emergence of chimeras in the network. As discussed in the literature energy harvesters can be efficient if the chaotic regimes can be suppressed and hence we focus our discussion towards synchronizing the nodes in the network when they are not in their chaotic regimes. We could successfully define the conditions to achieve complete synchronization in both periodic and quasiperiodically excited harvesters.


2018 ◽  
Vol 211 ◽  
pp. 05007
Author(s):  
Shengxi Zhou ◽  
Grzegorz Litak ◽  
Junyi Cao

We analyze dynamical responses of energy harvesters with a mechanical resonator possessing three potential wells. The frequency spectral analysis of simulated systems demonstrates that additional sub-harmonic and super-harmonic resonances appear. These additional solutions make the frequency broadband effect and effectively increase the voltage output. We show the characteristic features of the obtained solutions. Appearance of coexisting periodic solutions and chaotic solutions are also shortly discussed.


2015 ◽  
Vol 15 (02) ◽  
pp. 1450038 ◽  
Author(s):  
Onur Bilgen ◽  
Michael I. Friswell ◽  
Shaikh Faruque Ali ◽  
Grzegorz Litak

An inverted cantilevered beam vibration energy harvester with a tip mass is evaluated for its electromechanical efficiency and power output capacity in the presence of pure harmonic, pure random, and various combinations of harmonic and random base excitation cases. The energy harvester employs a composite piezoelectric material device that is bonded near the root of the beam. The tip mass is used to introduce nonlinearity to the system by inducing buckling in some configurations and avoiding it in others. The system dynamics include multiple solutions and jumps between the potential wells, and these are exploited in the harvesting device. This configuration exploits the nonlinear properties of the system using base excitation in conjunction with the tip mass at the end of the beam. Such a nonlinear device has the potential to work well when the input excitation does not have a dominant harmonic component at a fixed frequency. The paper presents an extensive experimental analysis, results and interesting conclusions derived directly from the experiments supported by numerical simulations.


Sign in / Sign up

Export Citation Format

Share Document