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A dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system for high-performance wind energy harvesting

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Science China(Technological Sciences) 2024年第1期67卷 221-239页

作者： MA XiaoQing ZHANG Hang MARGIELEWICZ Jerzy GĄSKA Damian WOLSZCZAK Piotr LITAK Grzegorz zhou shengxi School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Research&Development Institute in Shenzhen Northwestern Polytechnical UniversityShenzhen 518057China Faculty of Transport and Aviation Engineering Silesian University of TechnologyKrasińskiego 8Katowice 40-019Poland Department of Automation Lublin University of TechnologyNadbystrzycka 36Lublin 20-618Poland

Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered *** improve the working performance of energy harvesters effectively,a suitable structural design is *** paper proposes a dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system to enhance the functional performance of aeroelastic energy harvesters in environments with variable wind *** system contains two piezoelectric beams coupled by magnets(forming upstream and downstream energy harvesters),and each beam is attached with a foam cylinder.A corresponding dynamic model is provided,and output characteristics are obtained at different wind *** and experimental verification indicate that both upstream and downstream energy harvesters can realize efficient energy *** the wind speed exceeds a certain critical value,the amplitudes of the system’s displacement and voltage are *** wind speed threshold value is approximately 1.25 m/*** the wind speed and magnet spacing are 10.2 m/s and 20 mm,respectively,the output power of the system reaches 4.9×10^(−4)***,the wind speed threshold value of the proposed system can be adjusted by an equivalent nonlinear restoring force.

关键词： dual-beam structure piezoelectric energy harvester theoretical model nonlinear dynamics

自构建关联噪声下的随机共振及其在故障诊断上的应用

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振动与冲击 2024年第11期43卷 297-305页

作者：徐海涛杨涛周生喜西北工业大学航空学院西安710072 西北工业大学深圳研究院深圳518057

轴承作为旋转机械的重要组件之一,及时对其进行健康监测与更换可有效避免设备停机,减少经济损失。首先基于自构建关联噪声驱动下的随机共振系统(stochastic resonance system driven by self-constructingly correlated noise, DSCSR),... 详细信息

轴承作为旋转机械的重要组件之一,及时对其进行健康监测与更换可有效避免设备停机,减少经济损失。首先基于自构建关联噪声驱动下的随机共振系统(stochastic resonance system driven by self-constructingly correlated noise, DSCSR),推导了在正弦激励下该系统输出的理论信噪比(signal-to-noise ratio, SNR)。研究发现通过调节此非线性系统的参数可观察到随机共振现象。其次,针对将随机共振现象用于故障诊断时需要准确的先验知识这一局限性,进一步提出了基于功率谱的信噪比评价指标,并以此来确定非线性系统随机共振发生时的最优系统参数,对最优参数系统输出信号进行功率谱分析来判断故障类型。最后,通过轴承故障诊断试验以及实际风机轴承内圈故障实例证明了DSCSR方法的有效性,以及其增强微弱故障特征并抑制其他谐波以及噪声的干扰的能力。

关键词：关联噪声随机共振故障诊断非线性系统

Multistage oscillators for ultra-low frequency vibration isolation and energy harvesting

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Science China(Technological Sciences) 2022年第3期65卷 631-645页

作者： YANG Tao ZHANG YongQi zhou shengxi Department of Engineering Mechanics Northwestern Polytechnical UniversityXi’an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Limited by the mass,stiffness,barrier height and natural frequency of the oscillator,the existing structure or mechanism is still difficult to achieve vibration suppression and effective utilization under ultra-low frequency *** particular,it is difficult to break through the technical bottleneck of the integration and intelligence of vibration isolation and energy harvesting(VIEH).The introduction of nonlinearity is usually used to solve the problem of ultra-low frequency,and the integration problem can be overcome through electromechanical ***,the purpose of this article is to reveal and deeply explore the geometric nonlinearity and electromechanical coupling of multistage oscillators for ultra-low frequency *** kind of multifunctional oscillators can be realized by combining mechanical multistage coupling and electromechanical conversion *** experimental results confirm the development of multistage theory,and the results show that,especially in the case of multicoupling structures,the multistage oscillators with high-order quasi-zero stiffness can effectively reduce the initial frequencies of vibration isolation and the frequencies corresponding to the maximum output *** theoretical and experimental results in this paper show that the multistage oscillators are suitable for VIEH of ultra-low frequency sources.

关键词： multistage geometric nonlinearity vibration isolation energy harvesting

A review of nonlinear piezoelectric energy harvesting interface circuits in discrete components

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Applied Mathematics and Mechanics(English Edition) 2022年第7期43卷 1001-1026页

作者： Bin ZHANG Hongsheng LIU shengxi zhou Jun GAO School of Mechanical Electrical and Information EngineeringShandong UniversityWeihai 264209Shandong ProvinceChina School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

Piezoelectric energy harvesting is considered as an ideal power resource for low-power consumption gadgets in vibrational *** energy extraction efficiency depends highly on the interface circuit,and should be highly improved to meet the power *** nonlinear interface circuits in discrete components have been extensively explored and developed with the advantages of easy implementation,stable operation,high efficiency,and low *** paper reviews the state-of-the-art progress of nonlinear piezoelectric energy harvesting interface circuits in discrete ***,the working principles and the advantages/disadvantages of four classical interface circuits are ***,the improved circuits based on the four typical circuits and other types of circuits are introduced in detail,and the advantages/disadvantages,output power,efficiency,energy consumption,and practicability of these circuits are ***,the future development trends of nonlinear piezoelectric energy harvesting circuits,e.g.,self-powered extraction,low-power consumption,and broadband characteristic,are predicted.

关键词： piezoelectric nonlinear energy harvesting discrete component interface circuit

Recent progress on flutter‐based wind energy harvesting

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International Journal of Mechanical System Dynamics 2022年第1期2卷 82-98页

作者： Zhiyuan Li shengxi zhou Zhichun Yang School of Aeronautics Northwestern Polytechnical UniversityXi'anChina Research&Development Institute in Shenzhen Northwestern Polytechnical UniversityShenzhenChina

Wind energy harvesting technology can convert wind energy into electric energy to supply power for microelectronic *** has great potential in many specific applications and environments,such as remote areas,sea surfaces,mountains,and so *** the past few years,flutter‐based wind energy harvesting,which generates electric energy based on the limit cycle oscillation created by structural aeroelastic instability,has received increasing attention,and as a consequence,different energy harvesting structures,theories,and methods have been *** this paper,three types of flutter‐based energy harvesters(FEHs)including airfoil‐based,flat plate‐based,and flexible body‐based FEHs are reviewed,and related concepts and theoretical models are *** recent progress in FEH performance enhancement methods is classified into structural improvement and optimization,the introduction of nonlinearity,and hybrid structures and ***,the main FEH challenges are summarized,and future research directions are discussed.

关键词： dynamics flutter performance enhancement wind energy harvesting working principle

Improving the off-resonance energy harvesting performance using dynamic magnetic preloading

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Acta Mechanica Sinica 2020年第3期36卷 624-634页

作者： Feng Qian shengxi zhou Lei Zuo Department of Mechanical Engineering Virginia TechBlacksburgVA 24061USA School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

Piezoelectric stack transducers in d33 mode have a much higher mechanical-to-electric energy conversion efficiency compared with d3l mode piezoelectric ***,multilayered piezoelectric stacks usually operate in off-resonance due to the higher stiffness and thereby have a lower power output under low-frequency *** paper proposes to apply the dynamic magnetic pre-loading to a piezoelectric stack transducer to significantly increase the power *** energy harvesting system consists of a multilayered piezoelectric stack with a compliant force amplification frame,a proof mass,and two magnets configured in *** static force-displacement relationship of the magnets is identified from experiments and extended to a dynamic model capable of characterizing the dynamic magnetic *** electromechanical model is developed based on the theoretical derivation and the experimentally identified parameters to predict the voltage outputs under different resistive *** analytical solutions are derived by using the harmonic balance method and show good agreements with the numerical and experimental *** performance of the system is examined and compared with that of the harvester without magnetic *** influences of the distance between the two magnets and the electrical resistive loads on the power output are *** indicate the energy harvesting system with magnetic pre-loading can produce over thousand times more power than the system without magnetic pre-loading at the base excitation of 3 Hz and 0.5 m/s……2,far below the resonance at 243 Hz.

关键词： Energy harvesting Piezoelectric Off-resonance Harmonic balance analysis Magnetic interaction

On the stochastic response regimes of a tristable viscoelastic isolation system under delayed feedback control

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Science China(Technological Sciences) 2021年第4期64卷 858-868页

作者： HUANG DongMei zhou shengxi LI Wei LITAK Grzegorz School of Mathematics and Statistics Xidian UniversityXi'an 710071China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Department of Automation Lublin University of TechnologyLublin PL-20-61&Poland

In this paper,a tristable viscoelastic isolation system with stochastic excitation under both displacement and velocity delayed feedback control is ***,the theoretical expressions of the mean first-passage time(MFPT)to measure the activated escape between different potential wells are *** nonlinear transition dynamics due to the noise and time delays are mainly *** is found that the delay-induced behaviours affect the transitions between the equilibrium points of the system,the corresponding phenomenon of the delay-enhanced stability is *** this respect,the existence of the maxima of the MFPT1 and the MFPT2 is found in one ***,the MFPT1 and the MFPT2 show the monotonic behaviour with the increase of the noise ***,the stationary probability density of the amplitude and the stationary mean amplitude are *** influence regimes of the system parameters on both stationary probability density of the amplitude and the stationary mean amplitude are *** paper establishes the relationship between system parameters and dynamical properties of the tristable viscoelastic isolation *** provides a fundamental guidance for the optimization of the viscoelastic isolation by utilizing the technique of delayed feedback control.

关键词： stochastic excitation time delay viscoelastic isolation system dynamical response

Response regimes of nonlinear energy harvesters with a resistorinductor resonant circuit by complexification-averaging method

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Science China(Technological Sciences) 2021年第6期64卷 1212-1227页

作者： HUANG DongMei CHEN JiaYi zhou shengxi FANG XueLai LI Wei School of Mathematics and Statistics Xidian UniversityXi'an 710071China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

In this paper, the steady-state response regimes of nonlinear energy harvesters with a resistor-inductor resonant circuit are theoretically investigated. The complexification averaging(CA) method is used to theoretically analyze the energy harvesting performance and reduce the motion equations into a set of first-order differential equations. The amplitudes and phases of both the response displacement and the output voltage are derived, and the corresponding stability conditions are determined. The response regimes are studied with the variation of nonlinear stiffness coefficients and coupling parameters, which are verified by the time domain analysis. The frequency island phenomenon is found and analyzed. Additionally, the backbone curve for deducing the extreme vibration frequency and amplitude is derived. Simultaneously, the analytical expressions of the switching points(critical amplitude and frequency) to identify the hardening and softening properties are established. Accordingly, a criterion is given to determine the occurrence of the jump phenomenon, and its effectiveness is verified. Overall, this paper presents an in-depth theoretical analysis of nonlinear energy harvesters with a resistor-inductor resonant circuit. It presents the theoretical framework and guidance for more extensive evaluations and understanding the theoretical analysis of nonlinear energy harvesters with external circuits.

关键词： energy harvesting complexification averaging method nonlinear vibration

Fused-ring induced end-on orientation in conjugated molecular dyads toward efficient single-component organic solar cells

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聚集体(英文)

聚集体(英文) 2023年第2期4卷 291-299页

作者： Dongdong Xia shengxi zhou Wen Liang Tan Safakath Karuthedath Chengyi Xiao Chaowei Zhao Frédéric Laquai Christopher R.McNeill Weiwei Li Institute of Applied Chemistry Jiangxi Academy of SciencesNanchangChina Beijing Advanced Innovation Center for Soft Matter Science and Engineering&State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijingChina Department of Materials Science and Engineering Monash UniversityClaytonAustralia KAUST Solar Center(KSC) Physical Sciences and Engineering Division(PSE)Material Science and Engineering Program(MSE)King Abdullah University of Science and Technology(KAUST)ThuwalSaudi Arabia

The molecular orientations of conjugated materials on the substrate mainly include edge-on,face-on,and ***-on and face-on orientations have been widely observed,while end-on orientation has been rarely *** in organic solar cells(OSCs)charge transport is along the vertical direction,end-on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for *** this work,we for the first time obtained the preferential end-on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as *** was realized by introducing a fused-ring structure to replace linear terthiophenes with conjugated backbones,yielding F-MDPBI and L-MDPBI ***,a shifting trend of the molecular orientation from dominating edge-on in L-MDPBI to preferential end-on in F-MDPBI was *** a consequence,vertical charge carrier mobilities in F-MDPBI are one order of magnitude higher than those with preferential edge-on orientation,so single-component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L-MDPBI with preferential edge-on orientation.

关键词： conjugated molecular dyads crystallinity edge-on end-on single-component organic solar cells