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Periodic-phase-diagram similarity method for weak signal detection

International Journal of mechanical system Dynamics 2021年第2期1卷 248-255页

作者： Ruilan Tian Yangkun Zhang Shaopu Yang Kai Yuan Qiang Xue Quanrong Ren State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuangChina Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuangChina

The periodic-phase-diagram similarity method is proposed to identify the frequency of weak harmonic *** key technology is to find a set of optimal coefficients for Duffing system,which leads to the periodic motion under the influence of weak signal and strong *** the phase diagram similarity,the influences of strong noise on the similarity of periodic phase diagram are *** principle of highest similarity of periodic phase diagram with the same frequency is detected by discussing the persistence of similarity of periodic motion phase diagram under the strong noise and the periodic-phase-diagram similarity method is *** weak signals of early fault and strong noise are input into Duffing system to obtain the identified *** stochastic subharmonic Melnikov method is extended to obtain the conditions of the optimal coefficients for the identified *** on the results,the constructed frequency conversion harmonic weak signals are considered to form a datum periodic *** the change of frequency in the datum periodic system,the phase diagram similarity of the two constructed systems can be *** on the periodic-phase-diagram similarity method,the frequency of weak harmonic signals can be identified by the principle of highest similarity of periodic phase diagram with the same *** results of numerical simulation and the early fault diagnosis results of actual bearings verify the feasibility of the periodic-phase-diagram similarity *** accuracy of the detection effect is 97%,and the minimum signal-to-noise ratio is−80.71 dB.

关键词： periodic system signal-to-noise ratio stochastic subharmonic Melnikov method strong noise weak signal

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The Scheme to Determine the convergence Term of the Galerkin Method for Dynamic Analysis of Sandwich Plates on Nonlinear Foundations

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Acta Mechanica Solida Sinica 2021年第1期34卷 1-11页

作者： Hong-Yan chen Hu Ding Shao-Hua Li Li-Qun chen Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematicsand MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversitygShanghai 200444China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversitxyShiyiazhuang 050043China

The vibration of a plate resting on elastic foundations under a moving load is of great significance in the design of many engineering fields,such as the vehicle-pavement system and the aircraft-runway *** or runways are always laminated *** Galerkin truncation method is widely used in the research of *** number of truncation terms directly affects the convergence and accuracy of the response ***,the selection of the number of truncation terms has not been clearly stated.A nonlinear viscoelastic foundation model under a moving load is *** on the natural frequency of linear undisturbed derivative systems,the truncation terms are used to determine the convergence of vibration *** criterion for the convergence of the Galerkin truncation term is *** scheme is related to the natural frequency with high efficiency and *** the dynamic response of the sandwich beam under a moving load,the feasibility of the scheme is *** effects of different system parameters on the scheme and the truncation convergence of dynamic response are *** research in this paper can be used as a reference for the study of the vibration of elastic foundation ***,the model established and the truncation analysis method proposed are helpful for studying the vibration of vehicle-pavement system and related systems.

关键词： ndwich plate Galerkin method convergence Nonlinear foundation

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Dynamic analysis of axle box bearings on the high-speed train caused by wheel-rail excitation

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 441-460页

作者： Qiaoying MA Shaopu YANG Yongqiang LIU Baosen WANG Zechao LIU State Key Laboratory of Mechanical behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings,a dynamic model of the high-speed train including axle box bearings is ***,the dynamic response characteristics of the axle box bearing are *** investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel *** addition,experiments on both normal and faulty bearings are conducted separately,and the correctness of the model and some conclusions are *** to the research,track irregularity is unfavorable for bearing fault detection based on resonance *** the same speed conditions,the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its *** paper will contribute to a deeper understanding of the dynamic performance of axle box bearings.

关键词： high-speed train track irregularity wheel flat dynamic simulation

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Modeling,analysis,and simulation of X-shape quasi-zero-stiffness-roller vibration isolators

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Applied Mathematics and Mechanics(English Edition) 2022年第7期43卷 1027-1044页

作者： Xiaoye MAO Mengmeng YIN Hu DING Xiaofeng GENG Yongjun SHEN Liqun cHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Existing quasi-zero stiffness(QZS)isolators are *** terms of their advantages,a novel X-shape QZS isolator combined with the cam-roller-spring mechanism(cRSM)is *** from the existing X-shape isolators,oblique springs are used to enhance the negative stiffness of the ***,the cRSM is used to eliminate the gravity of the loading mass,while the X-shape structure leaves its static *** existing QZS isolators are demonstrated and classified according to their nonlinearity mechanisms and classical *** is shown that the oblique spring can realize negative stiffness based on the simplest *** X-shape has a strong capacity of loading mass,while the cRSM can achieve a designed restoring force at any *** proposed isolator combines all these advantages *** on the harmonic balance method(HBM)and the simulation,the displacement transmissibilities of the proposed isolator,the X-shape isolators just with oblique springs,and the X-shape isolators in the traditional form are *** results show that the proposed isolator has the lowest beginning isolation frequency and the smallest maximum displacement ***,it still has some disadvantages similar to the existing QZS *** means that its parameters should be designed carefully so as to avoid becoming a bistable system,in which there are two potential wells in the potential energy curve and thus the isolation performance will be worsened.

关键词： quasi-zero stiffness(QZS) cam-roller X-shape isolator nonlinear isolation

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Three-dimensional train-periodic slab track-subgrade dynamics model based on the iterative solution and Green's function method

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computers and structures 2025年 315卷

作者： Sun, Yu Zhang, Sen Xing, Mengting Shi, Zhiyong Liu, Pengfei College of Transportation Engineering Nanjing Tech University Nanjing210009 China Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures in Hebei Shijiazhuang Tiedao University Shijiazhuang050043 China College of Rail Transit Wuxi University Wuxi214105 China Department of Industrial Engineering University of Florence Florence50139 Italy State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

This paper develops an iterative solution model for the efficient and accurate simulation of the dynamics of a three-dimensional (3D) train-periodic slab track-subgrade (TPSTS) system. The entire system is divided into the train-rail subsystem and the periodic slab-subgrade subsystem. An ordinary differential equation (ODE) model of the train-rail system is established, and a step-moving strategy is employed to enhance the computational efficiency. A frequency-domain Green's function method (GFM) model is employed for modelling the periodic slab-subgrade. considering the periodicity, symmetry, and attenuation characteristics of the track structure, the Green's function of the slab-subgrade structure is obtained by conducting harmonic response analysis on a finite element model (FEM) of a quarter slab-subgrade structure. The proposed model is utilized to investigate the vibration characteristics of the high-speed train-track-subgrade system. The results indicate that the model exhibits good convergence, accuracy, and efficiency. The periodicity of the track structure has a significant impact on the statistical values of subgrade displacement and stress amplitudes along the track's longitudinal direction. At the subgrade surface, the amplitudes of displacement, stress, and acceleration exhibit fluctuations in the lateral direction of the track. However, with increasing depth, these amplitudes generally attenuate, leading to a more uniform distribution. © 2025 Elsevier Ltd

关键词： Railroad transportation

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Design and dynamic analysis of integrated architecture for vibration energy harvesting including piezoelectric frame and mechanical amplifier

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Applied Mathematics and Mechanics(English Edition) 2021年第6期42卷 755-770页

作者： Xiangjian DUAN Dongxing cAO Xiaoguang LP Yongjun SHEN Beijing Institute of Structure and Environment Engineering Beijing 100076China Faculty of Materials and Manufacturing Bejing University of TechnologyBeijing 100124China Beijing Key Laboratory of Nonlinear V ibrations and Strength of Mechanical Structures Beijing 100124China State Key Laboratory of Mechanical Behavior and System Safety of Trafic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Vibration energy harvesters(VEHs) can transform ambient vibration energy to electricity and have been widely investigated as promising self-powered devices for wireless sensor networks, wearable sensors, and applications of a micro-electro-mechanical system(MEMS). However, the ambient vibration is always too weak to hinder the high energy conversion efficiency. In this paper, the integrated frame composed of piezoelectric beams and mechanical amplifiers is proposed to improve the energy conversion efficiency of a VEH. First, the initial structures of a piezoelectric frame(PF) and an amplification frame(AF) are designed. The dynamic model is then established to analyze the influence of key structural parameters on the mechanical amplification factor. Finite element simulation is conducted to study the energy harvesting performance, where the stiffness characteristics and power output in the cases of series and parallel load resistance are discussed in detail. Furthermore, piezoelectric beams with variable cross-sections are introduced to optimize and improve the energy harvesting efficiency. Advantages of the PF with the AF are illustrated by comparison with conventional piezoelectric cantilever beams. The results show that the proposed integrated VEH has a good mechanical amplification capability and is more suitable for low-frequency vibration conditions.

关键词： vibration energy harvesting mechanical amplifier piezoelectric frame(PF) amplification frame(AF) variable cross-section beam

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Dynamic crushing behavior and energy absorption of hybrid auxetic metamaterial inspired by Islamic motif art

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Applied Mathematics and Mechanics(English Edition) 2023年第3期44卷 345-362页

作者： Ruilan TIAN Huaitong GUAN Xuhao LU Xiaolong ZHANG Huanan HAO Wenjie FENG Guanglei ZHANG Department of Engineering Mechanics Hebei Key Laboratory of Mechanics of Intelligent Materials and StructuresShijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Materials Science and Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Auxetic honeycomb structures are promising metamaterials with outstanding mechanical properties,and can be potentially used in energy absorption *** this study,a novel modified re-entrant hybrid auxetic metamaterial inspired by Islamic motif art is designed by integrating four-pointed double re-entrant motifs with symmetric semi-hexagonal unit cells to achieve a high energy absorption capacity(EAc).Theoretical analyses and numerical simulations are performed to examine the dynamic crushing behavior of the four-pointed double re-entrant combined structure(FDRcS).The developed finite element models(FEMs)are validated by the experiments under quasi-static *** deformation mode and stress-strain curves are further studied under low,medium,and high crushing *** theoretically predicted plateau stress of the FDRcS under different crushing velocities is consistent with the numerical simulation *** crushing stress and the EAc of the FDRcS are influenced by the geometric parameters and crushing *** FDRcS exhibits a negative Poisson's ratio(NPR),owing to the four-point re-entrant structure(RES).Moreover,the specific energy absorption(SEA)of these structures is higher than that of nonauxetic hexagonal and auxetic re-entrant structures,owing to the generation of more plastic hinges that dissipate more energy during dynamic crushing.

关键词： re-entrant honeycomb auxetic hybrid metamaterial energy-absorption dynamic crushing

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Study on vibration reduction of two-scale system coupled with dynamic vibration absorber

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1335-1352页

作者： Honglin WAN Xianghong LI Yongjun SHEN Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The dynamic vibration absorber with inerter and grounded stiffness(IGDVA)is used to control a two-scale system subject to a weak periodic *** vibration suppression effect is *** amplitude of the main system coupled with absorber is significantly reduced,and the high frequency vibration completely ***,through the slow-fast analysis and stability theory,it is found that the stability of the autonomous system exerts a notable regulating effect on the vibration response of the non-autonomous *** adding the dynamic vibrator absorber,the center in the autonomous system changes to an asymptotically stable focus,consequently suppressing the vibration in the non-autonomous *** research reveals that the parameters of the absorber affect the real parts of the eigenvalues of the autonomous system,thereby regulating the stability of the *** from a qualitative standpoint to a quantitative approach,a comparison of the solutions before and after the introduction of the dynamic absorber reveals that,when the grounded stiffness ratio and the mass ratio of the dynamic absorber are not equal,the high-frequency part in the analytical solution *** a result,this leads to a reduction in the amplitude of the trajectory,achieving a vibration reduction effect.

关键词： two-scale system dynamic vibration absorber vibration control inerter

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cluster oscillation and bifurcation of fractional-order Duffing system with two time scales

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Acta Mechanica Sinica 2020年第4期36卷 926-932页

作者： Yanli Wang Xianghong Li Yongjun Shen Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The dynamical behavior on fractional-order Duffing system with two time scales is investigated,and the point-cycle coupling type cluster oscillation is firstly observed *** taking the fractional order as bifurcation parameter,the dynamics of the autonomous Duffing system will become more complex than the corresponding integer-order one,and some typical phenomenon exist only in the fractional-order *** attractors exist in various parameter space,and Hopf bifurcation only happens while fractional order is bigger than 1 under certain parameter ***,the bifurcation behavior of the autonomous system may regulate dynamical phenomenon of the periodic excited *** results into the point-cycle coupling type cluster oscillation when the fractional order is bigger than *** related generation mechanism based on slow-fast analysis method is that the slow variation of periodic excitation makes the system periodically visit different attractors and critical points of different bifurcations of the autonomous system.

关键词： Fractional-order Duffing system cluster oscillation Slow-fast analysis method Bifurcation

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Adsorption Properties of calcined Modified Sepiolite on SO4^2- and cl^-

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 32-41页

作者：孙凯利王彩辉 ZHANG Guanglei NIU Han FU Shifeng WU Yueze YANG Jinhui State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Institute of Technology Co. Ltd.ShiJiaZhuang 050021China

Three different kinds of sepiolite(Type A, Type B and Sepiolite fiber) were processed by calcination and analyzed by thermogravimetric analysis(TG), X-ray diffraction diffractometer(XRD), scanning electron microscopy(SEM), BET(specific surface area from N2 adsorption isotherms), mercury intrusion porosimetry(MIP), and infrared spectroscopic analysis(IR), respectively. The results show that the adsorption performance of sepiolite can be changed by calcination and environment temperatures, especially for calcination. The adsorption capacity of sepiolite fiber is bigger than that of Type A and B, and adsorption capacity of each sepiolite to sulfate is smaller than that of the chloride ions. Especially, the maximum value for adsorption of the sepiolite fibers, calcined at 600 ℃ and water bath at 60 ℃, to chlorine ion and sulfate are 5.95 and 5.71 mg/g, respectively(mg/g : the ions quantity adsorbed by a unit of sepiolite weight). The minimum adsorption of calcined sepiolite fiber to sulfate ions increased from 5.02 to 5.55 mg/g. While microstructure analysis of sepiolite by TG indicated that its structure was, for temperature not exceeding 700 ℃, was not changed significantly. Sepiolite has a porous structure, especially for sepiolite fiber, which can be observed by SEM. BET indicates that sepiolite fiber has a larger pore volume than others and this can be increased by calcination. IR shows that the adsorption of sepiolite to cl-and SO42- belongs to physical absorption, instead of chemisorption.

关键词： adsorption chloridion sepiolite sulfate ion temperature

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