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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1807-1820页

作者： Jianing liU jinqiang li Ying WU School of Aerospace Engineering Xi’an Jiaotong UniversityXi’an 710049China College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin 150001China

Several types of acoustic metamaterials composed of resonant units have been developed to achieve low-frequency *** most of these structures,bandgaps are determined by their geometric configurations and material *** paper presents a frequency-displacement feedback control method for vibration suppression in a sandwich-like acoustic metamaterial *** band structure is theoretically derived using the Hamilton principle and validated by comparing the theoretical calculation results with the finite element simulation *** this method,the feedback voltage is related to the displacement of a resonator and the excitation *** applying a feedback voltage on the piezoelectric fiber-reinforced composite(PFRC)layers attached to a cantilever-mass resonator,the natural frequency of the resonator can be *** ensures that the bandgap moves in a frequency-dependent manner to keep the excitation frequency within the *** on this frequency-displacement feedback control strategy,the bandgap of the metamaterial plate can be effectively adjusted,and the vibration of the metamaterial plate can be significantly suppressed.

关键词： acoustic metamaterial Hamilton principle electromechanical coupling vibration control local resonance

Flutter and Thermal Buckling Properties and Active Control of Functionally Graded Piezoelectric Material Plate in Supersonic Airflow

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Acta Mechanica Solida Sinica 2020年第5期33卷 692-706页

作者： Yu Xue jinqiang li Fengming li Zhiguang Song College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin150001China

This paper is devoted to investigate the flutter and thermal buckling properties of the functionally graded piezoelectric material(FGPM)plate in supersonic airflow,and the active flutter control is carried out under different temperature *** piezoelectric material component of the FGPM plate has gradient changes along the thickness,such as piezoelectricity and dielectric *** supersonic piston theory is used to evaluate the aerodynamic *** on the first-order shear deformation theory and Hamilton’s principle with the assumed mode method,the equation of motion of the structural system is *** effect of aerodynamic pressure on the frequency and damping ratio of the FGPM plate is ***,the flutter and thermal buckling properties of the FGPM and pure metal plates are compared to show the superior aerothermoelastic properties of the FGPM *** influences of volume fraction exponent and temperature on the flutter and thermal buckling properties of the FGPM plate are also examined in *** LQR controller is adopted to achieve active flutter *** simulation results show that the present control method can largely improve dynamic stability of the FGPM plate in supersonic airflow and high-temperature environment.

关键词： Functionally graded piezoelectric material Flutter Thermal buckling Active control

Random Vibration Control of Laminated Composite Plates with Piezoelectric Fiber Reinforced Composites

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Acta Mechanica Solida Sinica 2016年第3期29卷 316-327页

作者： jinqiang li Zhuorui Ma Zhihua Wang Yoshihiro Narita College of Mechanics Shanxi Key Laboratory of Material Strength & Structural ImpactTaiyuan University of Technology Faculty of Engineering Hokkaido University

This paper presents an analysis of the active control of random vibration for lami- nated composite plates using piezoelectric fiber reinforced composites （PFRC）. With Hamilton＇s principle and the Rayleigh-Ritz method, the equation of motion for the resulting electromechani- cal coupling system is derived. A velocity feedback control rule is employed to obtain an effective active damping in the suppression of random vibration. The power spectral density and mean- square displacements of the random vibration for laminated plates under different control gains are simulated and the validity of the present control strategy is confirmed. The effect of piezoelec- tric fiber orientation in the PFRC layer on the random vibration suppression is also investigated. The analytical methodology can be expanded to other kinds of random vibration.

关键词： random vibration active control laminated composite plate velocity feedback,piezoelectric material

An Improved Space-Time Joint Anti-jamming Algorithm Based on Variable Step LMS

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Tsinghua Science and Technology 2017年第5期22卷 520-528页

作者： Dengao li jinqiang liu Jumin Zhao Gang Wu Xiaofang Zhao College of Information Engineering Taiyuan University of Technology

In wireless communication, the space-time anti-jamming method is widely applied because it shows better performance than the pure airspace and pure temporal anti-jamming methods. However, its application is limited by its computational complexity, and it cannot suppress narrowband interference that is in the same direction as the navigation signal. To solve these problems, we propose improved frequency filter to filter the narrowband interference from the desired signal direction in advance, meanwhile, an improved variable step Least Mean Square （LMS） method is proposed to complete the space-time array weights with fast iteration, thereby reducing computational complexity. The simulation results show that, compared with conventional methods, the anti-jamming capability of the proposed algorithm is significantly enhanced; and its complexity is significantly reduced.

关键词： Space-Time Adaptive Processing (STAP) Least Mean Square (LMS) computational complexity frequency domain filter

WAVE PROPAGATION IN TWO-DIMENSIONAL DISORDERED PIEZOELECTRIC PHONONIC CRYSTALS

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Acta Mechanica Solida Sinica 2008年第6期21卷 507-516页

作者： jinqiang li Fengming li Yuesheng Wang Kikuo Kishimoto P. O. Box 137 School of Astronautics Harbin Institute of Technology Harbin 150001 China Department of Mechanical Sciences and Engineering Tokyo Institute of Technology 2-12-1 O-okayama Meguro-ku Tokyo 152-8552 Japan Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China

The wave propagation is studied in two-dimensional disordered piezoelectric phononic crystals using the finite-difference time-domain （FDTD） method. For different cases of disorder, the transmission coefficients are calculated. The influences of disorders on band gaps are investigated. The results show that the disorder in the piezoelectric phononic crystals has more significant influences on the band gap in the low frequency regions than in the high frequency ones. The relation between the width of band gap and the direction of position disorder is also discussed. When the position disorder is along the direction perpendicular to the wave transmission, the piezoelectric phononic crystals have wider band gaps at low frequency regions than the case of position disorder being along the wave transmission direction. It can also be found that the effect of. size disorder on band gaps is analogous to that of location disorder. When the perturbation coefficient is big, it has more pronounced effects on the pass bands in the piezoelectric phononic crystals with both size and location disorders than in the piezoelectric phononic crystals with single disorder. In higher frequency regions the piezoelectric effect reduces the transmission coefficients. But for larger disorder degree, the effects of the piezoelectricity will be reduced.

关键词： phononic crystal piezoelectricity position disorder band gap FDTD method

Active Control of Thermo-mechanical Buckling of Composite Laminated Plates Using Piezoelectric Actuators

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Acta Mechanica Solida Sinica 2021年第3期34卷 369-380页

作者： Yao Zhang Yu Xue Wei Yuan Wensheng Ma jinqiang li Fengming li College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin 150001China Key Laboratory of Aero-engine Vibration Technique AECC Hunan Aviation Power Plant Research InstituteZhuzhou12000China

This paper is concerned with the active control of thermomechanical buckling of composite laminated plates using piezoelectric facesheets as *** four-variable trigonometric shear deformation theory and Hamilto's principle are applied to formulate the governing equation of structural *** temperature feedback control strategy is proposed to conduct the active control of thermal-mechanical *** simulation results show that the thermo-mechanical buckling of composite laminated plates can be effectively controlled by the presented control *** a specific control gain,the critical mechanical buckling load can remain constant at different *** effects of geometric parameters,fiber angle,stacking sequence,position of piezoelectric layer and boundary conditions on the active control of thermo-mechanical buckling are also investigated.

关键词： Buckling control Thermo-mechanical buckling Laminated plate Piezoelectric actuator Temperature feedback

Experimental study on out-of-plane seismic performance of precast composite sidewalls of utility tunnel with grouting-sleeve joints

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Underground Space 2024年第3期16卷 1-17页

作者： Zilan Zhong Guangfan li jinqiang li Jiaxu Shen Mi Zhao Xiuli Du Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China

The precast composite reinforced concrete wall with the advantages of fewer joints,superior impermeability and rapid construction provides an efficient and environmental friendly alternative in the construction of underground utility tunnels in the last few *** investigate the seismic performance of precast concrete composite walls of utility tunnels with grouting-sleeve connection under out-ofplane loads,a series of quasi-static cyclic tests were performed on the full-scale sidewall specimens with different axial compression ratios in this *** experimental results including the failure modes,crack distributions,and the influence of different connections on the out-of-plane seismic performance of precast concrete composite wall were carefully examined and compared with those from the cyclic tests of the cast-in-place sidewalls of the utility *** test results show that the seismic performance of the precast concrete composite sidewall specimen,such as the hysteresis curves,the ultimate bearing capacity,stiffness degradation pattern and the ductility ratio,is basically the same as that of the cast-in-place specimen,indicating that the seismic performance of the prefabricated structure is equivalent to that of the cast-in-place ***,the grouting-sleeves of the joints can effectively transfer the reinforcement stress until the failure of the precast concrete composite sidewall specimens,which exhibits excellent out-of-plane ductility and serviceability.

关键词： Precast concrete composite walls Cyclic response Seismic performance Grouting sleeve Failure mechanism

Actively tunable sandwich acoustic metamaterials with magnetorheological elastomers

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1875-1894页

作者： Jinhui liU Yu XUE Zhihong GAO A.O.KRUSHYNSKA jinqiang li College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin150001China Engineering and Technology Institute of Groningen(ENTEG) University of GroningenGroningen9700 ABThe Netherlands

Sandwich structures are widespread in engineering applications because of their advantageous mechanical ***,their acoustic performance has also been improved to enable attenuation of low-frequency vibrations induced by noisy ***,we propose a new design of sandwich plates(SPs)featuring a metamaterial core with an actively tunable low-frequency *** core contains magnetorheological elastomer(MRE)resonators which are arranged periodically and enable controlling wave attenuation by an external magnetic *** analytically estimate the sound transmission loss(STL)of the plate using the space harmonic expansion *** low frequency sound insulation performance is also analyzed by the equivalent dynamic density method,and the accuracy of the obtained results is verified by finite-element *** results demonstrate that the STL of the proposed plate is enhanced compared with a typical SP analog,and the induced bandgap can be effectively tuned to desired *** study further advances the field of actively controlled acoustic metamaterials,and paves the way to their practical applications.

关键词： sandwich plate(SP) magnetorheological elastomer(MRE) sound transmission loss(STL) vibration control acoustic metamaterial

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 BCH error correction scheme applied to FPGA with embedded memory

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Frontiers of Information Technology & Electronic Engineering 2021年第8期22卷 1127-1139页

作者： Yang liU Jie li Han WANG Debiao ZHANG Kaiqiang FENG jinqiang li National Key Laboratory for Electronic Measurement Technology North University of ChinaTaiyuan 030051China Shandong Aerospace Electronic Technology Institute Yantai 264000China

Given the potential for bit flipping of data on a memory medium,a high-speed parallel Bose-Chaudhuri-Hocquenghem(BCH)error correction scheme with modular characteristics,combining logic implementation and a look-up table,is *** is suitable for data error correction on a modern field programmable gate array full with on-chip embedded *** elaborate on the optimization method for each part of the system and analyze the realization process of this scheme in the case of the BCH code with an information bit length of 1024 bits and a code length of 1068 bits that corrects the 4-bit error.

关键词： Error correction algorithm Bose-Chaudhuri-Hocquenghem(BCH)code Field programmable gate array(FPGA) NAND flash