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Nonlinear dynamic analysis of a photonic crystal nanocavity resonator

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Applied Mathematics and Mechanics(English Edition) 2019年第1期40卷 139-152页

作者： Fengrui LIU Han YAN wenming zhang State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong University

A nonlinear dynamic model of a one-dimensional photonic crystal nanocavity resonator is presented. It considers the internal tensile stress and the geometric characteristics of a photonic crystal with rectangular(and circular) holes. The solution of the dynamic model shows that the internal tensile stress can suppress the hardening and softening behaviors of the resonator. However, the stress can reduce the amplitude, which is not conducive to an improvement of the sensitivity of the sensor. It is demonstrated that with an optimized beam length, the normalized frequency drift of the beam can be stabilized within 1% when the optical power increases from 2 mW to 6 mW. When the hole size of the resonator beam is close to the beam width, its increase can lead to a sharp rise of the resonant frequency and the promotion of hardening behavior. Moreover,the increase in the optical power initially leads to the softening behavior of the resonator followed by an intensification of the hardening behavior. These theoretical and numerical results are helpful in understanding the intrinsic mechanism of the nonlinear response of an optomechanical resonator, with the objective of avoiding the nonlinear phenomena by optimizing key parameters.

关键词： nonlinear dynamic resonator photonic crystal softening and hardening behaviors

Evolution of suspension bridge structural systems,design theories,and shape-finding methods:A literature survey

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 225-244页

作者： wenming zhang Genmin Tian Yupeng Chen Key Laboratory of Concrete and Pre-stressed Concrete Structures of Ministry of Education Southeast UniversityNanjing 210096China State Key Laboratory of Safety Durability and Healthy Operation of Long Span BridgesSoutheast UniversityNanjing 210096China

Modern suspension bridges exhibit a trend of lighter structures,more diversified structural forms,and longer spans,the latter already exceeding two *** performance under dead and live loads depends on their structural and main cable systems,while cablesupported bridges especially rely on the design analysis and construction control of the main *** literary survey systematically analyzes the research progress and state-ofthe-art status quo in the structural systems and design theories of suspension bridges,focusing on the structural systems,main cable shape analyses,live load effect analyses,and emerging lucrative research *** than 100 reliable references have been surveyed.(1)Multi-span or multi-main cable schemes appeal to increasing attention,which may become a better choice in terms of structural systems in scenarios with extremely long spans and heavy *** cable layouts,such as spatial main cables and hybrid cable-stayed suspension systems have also become feasible approaches for enhancing structural stiffness.(2)The shape-finding analysis during the construction phase is more complex and has more essential factors than that of the completed bridge *** theories combining analytical methods and finite element methods are more suitable for the shape-finding analysis of complex cable systems than any single theory of the two,especially for novel cable systems.(3)The live load effect analysis methods based on traditional deflection theory or modified/improved deflection theories still have wide applications,but the refined theory of treating hangers as discrete members is also constantly developing,which is expected to provide new ideas for more complex structural analysis under the different types of live loads and their distribution forms.

关键词： Suspension bridges Structural system Cable analysis Shape-finding analysis Construction control and calculation Live load effect

Nonlinear modal coupling in a T-shaped piezoelectric resonator induced by stiffness hardening effect

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Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 777-792页

作者： Lei LI Hanbiao LIU Jianxin HAN wenming zhang School of Transportation and Vehicle Engineering Shandong University of TechnologyZibo 255049Shandong ProvinceChina State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Tianjin Key Laboratory of High Speed Cutting and Precision Machining Tianjin University of Technology and EducationTianjin 300222China

The nonlinear modal coupling in a T-shaped piezoelectric resonator,when the former two natural frequencies are away from 1:2,is *** sweeping up the exciting frequency shows that the horizontal beam exhibits a nonlinear hardening *** first primary resonance of the vertical beam,owing to modal coupling,exhibits an abrupt amplitude increase,namely the Hopf *** frequency comb phenomenon induced by modal coupling is measured experimentally.A Duffing-Mathieu coupled model is theoretically introduced to derive the conditions of the modal coupling and frequency comb *** results demonstrate that the modal coupling results from nonlinear stiffness hardening and is strictly dependent on the loading range and sweeping form of the driving voltage and the frequency of the piezoelectric patches.

关键词： coupled vibration resonator nonlinear dynamics bifurcation hardening behavior frequency comb

CoN_(x)C active sites-rich three-dimensional porous carbon nanofibers network derived from bacterial cellulose and bimetal-ZIFs as efficient multifunctional electrocatalyst for rechargeable Zn–air batteries

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Journal of Energy Chemistry 2020年第12期29卷 323-332页

作者： wenming zhang Jingjing Chu Shifeng Li Yanan Li Ling Li National-Local Joint Engineering Laboratory of New Energy Photoelectric Devices College of Physics Science and TechnologyHebei UniversityBaoding 071002HebeiChina

In this work, a CoNxC active sites-rich three-dimensional porous carbon nanofibers network derived from bacterial cellulose and bimetal-ZIFs is prepared via a nucleation growth strategy and a pyrolysis *** material displays excellent electrocatalytic activity for the oxygen reduction reaction, reaching a high limiting diffusion current density of -7.8 mA cm^(-2), outperforming metal–organic frameworks derived multifunctional electrocatalysts, and oxygen evolution reaction and hydrogen evolution reaction with low overpotentials of 380 and 107 mV, respectively. When the electrochemical properties are further evaluated, the electrocatalyst as an air cathode for Zn-air batteries exhibits a high cycling stability for63 h as well as a maximum power density of 308 mW cm^(-2), which is better than those for most Zn-air batteries reported to date. In addition, a power density of 152 mW cm^(-2) is provided by the solid-state Zn-air batteries, and the cycling stability is outstanding for 24 h. The remarkable electrocatalytic properties are attributed to the synergistic effect of the 3 D porous carbon nanofibers network and abundant inserted CoNxC active sites, which enable the fast transmission of ions and mass and simultaneously provide a large contact area for the electrode/electrolyte.

关键词： Bacterial cellulose Bimetal-ZIFs CoNxC active sites 3D nitrogen-doped porous carbon nanofiber Zn-air batteries

Parametric identification of time-varying systems from free vibration using intrinsic chirp component decomposition

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Acta Mechanica Sinica 2020年第1期36卷 188-205页

作者： Sha Wei Shiqian Chen Xingjian Dong Zhike Peng wenming zhang School of Mechanics and Engineering Science Shanghai UniversityShanghai200072China Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai UniversityShanghai200072China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai200240China

Time-varying systems are applied extensively in practical applications,and their related parameter identification techniques are of great significance for structural health monitoring of time-varying *** improve the identification accuracy for time-varying systems,this study puts forward a novel parameter identification approach in the time-frequency domain using intrinsic chirp component decomposition(ICCD).ICCD is a powerful tool for signal decomposition and parameter extraction,with good signal reconstruction capability in a high-noise *** maintain good identification effects for the time-varying system in a noisy environment,the proposed method introduces a redundant Fourier model for the non-stationary signal,including instantaneous frequency(IF)and instantaneous amplitude(IA).The accuracy and effectiveness of the proposed approach are demonstrated by a single-degree-of-freedom system with three types of time-varying parameters,as well as an example of a multi-degree-of-freedom *** effects of different levels of measured noise on the identified results are also discussed in *** results show that the proposed method is very effective in tracking the smooth,periodical,and non-smooth variations of time-varying systems over the entire identification time period even when the response signal is contaminated by intense noise.

关键词： System identification Time-varying system Time-frequency domain Intrinsic chirp component decomposition

The synergistic effect of Lewis acidic etching V_(4)C_(3)(MXene)@CuSe_(2)/CoSe_(2) as an advanced cathode material for aluminum batteries

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Journal of Materials Science & Technology 2024年第10期177卷 205-213页

作者： Yi Wang Hanqing Gu Yong Lu wenming zhang Zhanyu Li Hebei Key Laboratory of Optic-Electronic Information and Materials National&Local Joint Engineering Laboratory of New Energy Photoelectric DevicesCollege of Physics Science and TechnologyHebei UniversityBaoding 071002China

Herein,we focused on the development of the V_(4)C_(3) MXene composite bimetallic selenide heterostruc-ture(V_(4)C_(3)@CuSe_(2)/CoSe_(2))as a cathode material for aluminum *** heterostructure was pre-pared through a Lewis melt salt etching and selenization *** capitalizing on the synergistic effect between the bimetallic selenide and V_(4)C_(3) MXene,V_(4)C_(3)@CuSe_(2)/CoSe_(2) exhibited rapid charge transfer and demonstrated superior discharge specific capacity compared to V_(4)C_(3) composite monometallic ***,the incorporation of V_(4)C_(3) improved the material's stability during charging/*** initial discharge specific capacity of V_(4)C_(3)@CuSe_(2)/CoSe_(2) reached an impressive 809 mAh g^(-1) at 1 Ag^(-1).Even after nearly 3000 cycles,it retained a substantial capacity of 169.1 mAh g^(-1).Ex-situ XPS analysis confirmed the reversible valence transitions of Cu,Co,and Se elements as the main energy storage reac-tions taking place in the cathode *** functional theory analysis provided further insights,revealing that the strong metallic behavior of the heterostructure stemmed from the charge rearrange-ment facilitated by the bimetallic selenide structure and the optimization of the energy level ***,the presence of the bimetallic selenide structure significantly improved the adsorption ef-ficiency of[AlCl4]^(-).Overall,this research contributes to the advancement of rechargeable aluminum ion batteries and presents a promising avenue for future developments in composite metal selenide struc-tures and MXene-based materials.

关键词： Rechargeable aluminum batteries V_(4)C_(3) MXene Bimetallic selenides Heterostructure Electrochemical performance

Targeted energy transfer of a parallel nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2019年第5期40卷 621-630页

作者： Yimin WEI Sha WEI Qianlong zhang Xinjian DONG Zhike PENG wenming zhang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

A parallel nonlinear energy sink(NES) is proposed and analyzed. The parallel NES is composed of a vibro-impact(VI) NES and a cubic NES. The dynamical equation is given, and the essential analytical investigation is carried out to deal with the cubic nonlinearity and impact nonlinearity. Multiple time-scale expansion is introduced, and the zeroth order is derived to give a rough outline of the system. The underlying Hamilton dynamic equation is given, and then the optimal stiffness is expressed. The clearance is regarded as a critical factor for the VI. Based on the periodical impact treatment by analytical investigation, the relationships of the cubic stiffness, the clearance, and the zeroth-order attenuation amplitude of the linear primary oscillator(LPO) are obtained.A cubic NES under the optimal condition is compared with the parallel NES. Harmonic signals, harmonic signals with noises, and the excitation generated by a second-order?lter are considered as the potential excitation forces on the system. The targeted energy transfer(TET) in the designed parallel NES is shown to be more e?cient.

关键词： targeted energy transfer (TET) nonlinear energy sink (NES) nonlinear vibration absorber impact vibration reduction

Uncertainty quantification for stochastic dynamical systems using time-dependent stochastic bases

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Applied Mathematics and Mechanics(English Edition) 2019年第1期40卷 63-84页

作者： Jinchun LAN Qianlong zhang Sha WEI Zhike PENG Xinjian DONG wenming zhang State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong University

A novel method based on time-dependent stochastic orthogonal bases for stochastic response surface approximation is proposed to overcome the problem of significant errors in the utilization of the generalized polynomial chaos(GPC) method that approximates the stochastic response by orthogonal polynomials. The accuracy and effectiveness of the method are illustrated by different numerical examples including both linear and nonlinear problems. The results indicate that the proposed method modifies the stochastic bases adaptively, and has a better approximation for the probability density function in contrast to the GPC method.

关键词： uncertainty quantification stochastic response surface approximation timedependent orthogonal bases polynomial chaos

Modal identification of multi-degree-of-freedom structures based on intrinsic chirp component decomposition method

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Applied Mathematics and Mechanics(English Edition) 2019年第12期40卷 1741-1758页

作者： Sha WEI Shiqian CHEN Zhike PENG Xingjian DONG wenming zhang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

Modal parameter identification is a mature ***,there are some challenges in its practical applications such as the identification of vibration systems involving closely spaced modes and intensive noise *** paper proposes a new time-frequency method based on intrinsic chirp component decomposition(ICCD)to address these *** this method,a redundant Fourier model is used to ameliorate border distortions and improve the accuracy of signal *** effectiveness and accuracy of the proposed method are illustrated using three examples:a cantilever beam structure with intensive noise contamination or environmental interference,a four-degree-of-freedom structure with two closely spaced modes,and an impact test on a cantilever rectangular *** comparison with the identification method based on the empirical wavelet transform(EWT),it is shown that the presented method is effective,even in a high-noise environment,and the dynamic characteristics of closely spaced modes are accurately determined.

关键词： modal identification closely spaced mode time-frequency domain intrinsic chirp component decomposition(ICCD) multi-degree-of-freedom(MDOF) system