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A viscoelastic metamaterial beam for integrated vibration isolation and energy harvesting

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1243-1260页

作者： Long ZHAO Zeqi LU Hu DING Liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai Frontier Science Center of MechanoinformaticsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China School of Microelectronics Shanghai UniversityShanghai201800China

Locally resonant metamaterials have low-frequency band gaps and the capability of converging vibratory energy in the band gaps at resonant *** has been demonstrated by several researchers that the dissipatioin of vibratory energy within the band gap can be improved by using viscoelastic *** paper designs an integrated viscoelastic metamaterial for energy harvesting and vibration *** viscoelastic metamaterial is achieved by a viscoelastic beam periodically arrayed with spatial ball-pendulum nonlinear energy *** nonlinear resonator with an energy harvesting function is achieved by placing a free-rolling magnetic ball in a spherical cavity with an additional induction *** dynamic equations of viscoelastic metamaterials under transverse excitation are established,and the energy harvesting and vibration isolation characteristics within the dispersion relation of viscoelastic metamaterials are *** results show that the vibrations of the main body of the viscoelastic metamaterial beam are significantly suppressed in the frequency range of the local resonance band *** the same time,the elastic waves are limited in the nonlinear resonator with an energy harvesting function,which improves the energy ***,an experimental platform of viscoelastic metamaterial vibration is established for validation purposes.

关键词： viscoelastic metamaterial nonlinear vibration vibration isolation energy harvesting

Multi-layer quasi-zero-stiffness meta-structure for high-efficiency vibration isolation at low frequency

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1189-1208页

作者： Jiahao ZHOU Jiaxi ZHOU Hongbin PAN Kai WANG Changqi CAI Guilin WEN College of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body The Ministry of Science and TechnologyChangsha410082China School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou310018China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004Hebei ProvinceChina

An easily stackable multi-layer quasi-zero-stiffness(ML-QZS)meta-structure is proposed to achieve highly efficient vibration isolation performance at low ***,the distributed shape optimization method is used to design the unit cel,i.e.,the single-layer QZS(SL-QZS)***,the stiffness feature of the unit cell is investigated and verified through static ***,the unit cells are stacked one by one along the direction of vibration isolation,and thus the ML-QZS meta-structure is ***,the dynamic modeling of the ML-QZS vibration isolation metastructure is conducted,and the dynamic responses are obtained from the equations of motion,and verified by finite element(FE)***,a prototype of the ML-QZS vibration isolation meta-structure is fabricated by additive manufacturing,and the vibration isolation performance is evaluated *** results show that the vibration isolation performance substantially enhances when the number of unit cells *** importantly,the ML-QZS meta-structure can be easily extended in the direction of vibration isolation when the unit cells are properly ***,the ML-FQZS vibration isolation meta-structure should be a fascinating solution for highly efficient vibration isolation performance at low frequency.

关键词： quasi-zero stiffness(QZS) meta-structure high efficiency low frequency vibration isolation

Nonlinear vibration isolation of Spacecraft System by a Bionic Variable-Stiffness Device Enhanced by Electromagnetic Component

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Acta Mechanica Solida Sinica 2023年第6期36卷 921-932页

作者： Zeyu Chai Xuyuan Song Jian Zang Yewei Zhang College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China

This study addresses the modified bionic vibration isolation technology by introducing the electromagnetic system to simulate biological damping *** has been proven effective in improving the vibration *** assuming the spacecraft-adapter system as a two-degree-of-freedom system,an excellent simplified model can be *** novel bionic vibration isolation device(ABVS-EMVI),which combines an active bionic variable-stiffness device(ABVSVI)with the electromagnetic system,is proposed for the purpose of isolating vibration and harvesting energy at the same *** dynamic equations of the spacecraft-adapter system with ABVS-EMVI are obtained using the Taylor expansion within the framework of the Lagrange equation,and the harmonic balance method is introduced to acquire the amplitude and voltage response of the *** results indicate that the electromagnetic system can enhance the vibration isolation performance and provide energy harvesting *** confirming the ability of ABVS-EMVI to deal with different forms and amplitudes of excitation,the performance of vibration isolation and energy harvesting is investigated in terms of various parameters,and several new conclusions have been drawn.

关键词： Bionic structure Electromagnetic system vibration isolation Energy harvesting

Self-synchronization theory of dual motor driven vibration system with two-stage vibration isolation frame

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Applied Mathematics and Mechanics(English Edition) 2015年第2期36卷 265-278页

作者： He LI Dan LIU Lai JIANG Chunyu ZHAO Bangchun WEN School of Mechanical Engineering and Automation Northeastern University

This paper studies self-synchronization and stability of a dual-motor driven vibration system with a two-stage vibration isolation frame. Oscillation amplitude of the material box large enough can be ensured on the vibration system in order to screen materials. Reduction of the dynamic load transmitted to the foundation can also be achieved for the vibration system. A Lagrange equation is used to set up the motion differential equations of the system, and a dimensionless coupled equation of the eccentric rotors is obtained using a method of modified average small parameter. According to the existence condition of zero solution in the dimensionless coupled equation of the eccentric rotors, the precondition for commencing self-synchronization motion is *** stability condition of self-synchronization is obtained based on the Routh-Hurwitz criterion. The theoretical analysis is validated by simulations and experiments.

关键词： self-synchronization vibration system stability vibration isolation

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

Bandgaps and vibration isolation of local resonance sandwich-like plate with simply supported overhanging beam

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Applied Mathematics and Mechanics(English Edition) 2021年第11期42卷 1555-1570页

作者： Chenxu QIANG Yuxin HAO Wei ZHANG Jinqiang LI Shaowu YANG Yuteng CAO College of Mechanical Engineering Beijing Information Science and Technology UniversityBeijing 100192China College of Mechanical Engineering Beijing University of TechnologyBeijing 100124China College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin 150001China

The concept of local resonance phononic crystals proposed in recent years provides a new chance for theoretical and technical breakthroughs in the structural vibration *** this paper,a novel sandwich-like plate model with local resonator to acquire specific low-frequency bandgaps is *** core layer of the present local resonator is composed by the simply supported overhanging beam,linear spring and mass block,and well connected with the upper and lower surface *** simply supported overhanging beam is free at right end,and an additional linear spring is added at the left *** wave equation is established based on the Hamilton principle,and the bending wave bandgap is further *** theoretical results are verified by the COMSOL finite element *** bandgaps and vibration characteristics of the local resonance sandwich-like plate are studied in *** factors which could have effects on the bandgap characteristics,such as the structural damping,mass of vibrator,position of vibrator,bending stiffness of the beam,and the boundary conditions of the sandwich-like plates,are *** result shows that the stopband is determined by the natural frequency of the resonator,the mass ratio of the resonator,and the surface *** shows that the width of bandgap is greatly affected by the damping ratio of the ***,it can also be found that the boundary conditions can affect the isolation efficiency.

关键词： local resonance sandwich-like plate elastic wave bandgap vibration isolation

A Closed-Loop Dynamic Controller for Active vibration isolation Working on A Parallel Wheel-Legged Robot

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 147-160页

作者： Fei Guo Shoukun Wang Daohe Liu Junzheng Wang School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Human Factors Engineering China Astronaut Research and Training CenterBeijing 100094China China State Shipbuilding Corporation Systems Engineering Research Institute Beijing 100048China

Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged ***,it is difficult to obtain its precise dynamic model,because of the nonlinearity and uncertainty of the heavy *** paper presents a dynamic control framework with a decentralized structure for single wheel-leg,position tracking based on model predictive control(MPC)and adaptive impedance module from inside to *** the Newton-Euler dynamic model of the Stewart mechanism,the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of *** actuating force naturally enables each strut to stretch and retract,thereby realizing six degrees-of-freedom(6-DOFs)position-tracking for Stewart *** adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along *** adjustment allows the robot to adequately control the desired support force tracking,isolating the robot body from vibration that is generated from unknown *** availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate *** comparing the proportional and integral(PI)and constant impedance controllers,better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder,as well as an inertial measurement unit(IMU)mounted on the robot *** proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.

关键词： Wheel-legged hybrid robot Adaptive impedance control Model predictive control Stewart mechanism vibration isolation Parallel robot

Dynamic Analysis and Decoupling Control of Octo-pneumatic Actuator vibration isolation Platform

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Chinese Journal of Mechanical Engineering 2009年第1期22卷 116-123页

作者： WANG Xiaolei YANG QinNun ZHENG Gangtie Department of Aerospace Engineering Harbin Institute of Technology Harbin 150001 China College of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Department of Aeronautics andAstronautics Tsinghua University Beijing 100084 China

Control of a six-DOF vibration isolation platform is generally difficult which is due to the strong coupling among its input and output channels. The dynamic behavior and decoupling approach of a six-DOF vibration isolation platform with eight pneumatic actuators are investigated. Owing to the symmetric configuration design of the platform, the coupling among different channels is greatly weakened. When the payload＇s principal axes of inertia parallel to the platform＇s axes of symmetry and the payload＇s center of mass is at the extension line of the platform＇s central axis, the motion can be decomposed into two independent single-input single-output channels and two independent two-input two-output subsystems. The second-order subsystems are decoupled further with the simultaneous matrix diagonalization. Thus a decoupling control strategy is developed. Effectiveness of the decoupling approach is verified through experiments of the platform, and the experimental results show that vibrations of the platform are attenuated obviously owing to the active control.

关键词： decoupling control vibration isolation eight actuators pneumatic actuator

Research on linear/nonlinear viscous damping and hysteretic damping in nonlinear vibration isolation systems

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Applied Mathematics and Mechanics(English Edition) 2020年第7期41卷 983-998页

作者： Zhong ZHANG Muqing NIU Kai YUAN Yewei ZHANG Science and Technology on Reliability and Environment Engineering Laboratory Beijing Institute of Structure and Environment EngineeringBeijing 100076China School of Science Harbin Institute of TechnologyShenzhen 518055China College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China

A nonlinear vibration isolation system is promising to provide a high-efficient broadband isolation *** this paper,a generalized vibration isolation system is established with nonlinear stiffness,nonlinear viscous damping,and Bouc-Wen(BW)hysteretic *** approximate analytical analysis is performed based on a harmonic balance method(HBM)and an alternating frequency/time(AFT)domain *** evaluate the damping effect,a generalized equivalent damping ratio is defined with the stiffness-varying characteristics.A comprehensive comparison of different kinds of damping is made through numerical *** is found that the damping ratio of the linear damping is related to the stiffness-varying characteristics while the damping ratios of two kinds of nonlinear damping are related to the responding *** linear damping,hysteretic damping,and nonlinear viscous damping are suitable for the small-amplitude,medium-amplitude,and large-amplitude conditions,*** hysteretic damping has an extra advantage of broadband isolation.

关键词： vibration isolation nonlinear damping Bouc-Wen(BW)model harmonic balance method(HBM)