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Science China(Technological Sciences) 2010年第7期53卷 2008-2014页

作者： Billie F SPENCER Department of Civil and Environmental Engineering University of Illinois at Urbana-Champaign

To ensure the anti-earthquake performances of super-long-span suspension bridges, effective devices should be employed to control the seismic response of key sections. In this paper, four kinds of assessment functions for seismic response control effect are formulated based on the mechanism of seismic response control with dampers and the seismic response characteristics of long-span suspension bridges. A new optimal placement method of dampers using penalty function and first-order optimization theory is then proposed. Runyang suspension bridge (RSB) with a main span of 1490 m is then taken as an example. After seismic response time-history analyses on RSB using different placements of dampers, the analysis results are optimized by employing the optimal placement method and the optimal placements of dampers with the four assessment functions are then achieved respectively. Comparison of the four optimal control effects show that different assessment functions can lead to different optimal placements when the number of dampers is certain, but all placements of dampers can reduce the seismic response of RSB significantly. The selection of assessment functions and damper optimal placement should be determined by the structural characteristics and by what is considered in the structures. Results also show that the first-order optimization is an effective method on determining the optimal placement of dampers.

关键词： suspension bridge seismic control damper placement control effect assessment first-order optimization method

Experimental research on the multilayer compartmental particle damper and its application methods on long-period bridge structures

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 751-766页

作者： Zhenyuan LUO Weiming YAN Weibing XU Qinfei ZHENG Baoshun WANG Beijing Key Laboratory of Earthquake Engineering and Structural Retrofit Beijing University of Technology Beijing 100124 China

Particle damping technology has attracted extensive research and engineering application interest in the field of vibration control due to its prominent advantages, including wide working frequency bands, ease of installation, longer durability and insensitivity to extreme temperatures. To introduce particle damping technology to long-period structure seismic control, a novel multilayer compartmental particle damper (MCPD) was proposed, and a 1/20 scale test model of a typical long-period self-anchored suspension bridge with a single tower was designed and fabricated. The model was subjected to a series of shaking table tests with and without the MCPD. The results showed that the seismic responses of the flexible or semi-flexible bridge towers of long-period bridges influence the seismic responses of the main beam. The MCPD can be conveniently installed on the main beam and bridge tower and can effectively reduce the longitudinal peak displacement and the root mean square acceleration of the main beam and tower. In addition, no particle accumulation was observed during the tests. A well-designed MCPD can achieve significant damping for long-period structures under seismic excitations of different intensities. These results indicate that the application of MCPDs for seismic control of single-tower self-anchored suspension bridges and other long-period structures is viable.

关键词： energy dissipation devices multilayer compartmental particle damper self-anchored suspension bridges shaking tables test long-period structure seismic control

Smart Semi-active PID-ACO control strategy for tower vibration reduction in Wind Turbines with MR damper

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 887-902页

作者： Mahmudur Rahman Zhi Chao Ong Wen Tong Chong Sabariah Julai Department of Mechanical Engineering Faculty of Engineering University of Malaya

Wind turbine technology is well known around the globe as an eco-friendly and eff ective renewable power source. However, this technology often faces reliability problems due to structural vibration. This study proposes a smart semi-active vibration control system using Magnetorheological (MR) dampers where feedback controllers are optimized with nature-inspired algorithms. Proportional integral derivative (PID) and Proportional integral (PI) controllers are designed to achieve the optimal desired force and current input for MR the damper. PID control parameters are optimized using an Ant colony optimization (ACO) algorithm. The eff ectiveness of the ACO algorithm is validated by comparing its performance with Ziegler-Nichols (Z-N) and particle swarm optimization (PSO). The placement of the MR damper on the tower is also investigated to ensure structural balance and optimal desired force from the MR damper. The simulation results show that the proposed semi-active PID-ACO control strategy can signifi cantly reduce vibration on the wind turbine tower under diff erent frequencies (i.e., 67%, 73%, 79% and 34.4% at 2 Hz, 3 Hz, 4.6 Hz and 6 Hz, respectively) and amplitudes (i.e. 50%, 58% and 67% for 50 N, 80 N, and 100 N, respectively). In this study, the simulation model is validated with an experimental study in terms of natural frequency, mode shape and uncontrolled response at the 1st mode. The proposed PID-ACO control strategy and optimal MR damper position is also implemented on a lab-scaled wind turbine tower model. The results show that the vibration reduction rate is 66% and 73% in the experimental and simulation study, respectively, at the 1st mode.

关键词： ant colony optimization fi nite diff erence method magnetorheological damper PID-ACO controller semiactive control system identifi cation wind turbine tower

Control performance comparison between tuned liquid damper and tuned liquid column damper using real-time hybrid simulation

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Earthquake Engineering and Engineering Vibration 2019年第3期18卷 695-701页

作者： Zhu Fei Wang Jinting Jin Feng Lu Liqiao State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Changjiang Institute of Survey Planning Design and Research Wuhan 430010 China

Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.

关键词： tuned liquid damper tuned liquid column damper real-time hybrid simulation control effi ciency structural control parametric study

Design of a tunable mass damper for mitigating vibrations in milling of cylindrical parts

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Chinese Journal of Aeronautics 2019年第3期32卷 748-758页

作者： Heng YUAN Min WAN Yun YANG School of Mechanical Engineering Northwestern Polytechnical University State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical University

Milling the free-end of cylindrical parts, which are vertically fixed on the machine table,often suffers from large chatter vibrations. This kind of phenomenon is harmful to the cutting process. Therefore, it is of great importance to develop means to suppress these undesirable *** paper proposes a new idea for designing a tunable mass damper(TMD) to reduce vibrations in milling of cylindrical parts. Frequency response function(FRF) of the milling system is derived to comprehensively reveal the influence of both the dynamic response of the machine tools and the TMD. Critical axial depth of cut, which is usually used to characterize the process stability, is formulated by considering the FRFs of both the milling system itself and the TMD. Maximization of critical axial depth of cut is taken as objective function, while kernel dynamic parameters of TMD,which are involved in the derived expression of critical axial depth of cut, are extracted as designable variables. Optimization procedure is carried out to adjust the parameters of TMD by using sequential quadratic programming algorithm. A series of experiments with a designed passive TMD validate that the design has a good performance in reducing vibrations and improving stability of milling process.

关键词： Chatter Milling Mitigation of vibrations Stability Tunable mass damper (TMD)

Dynamic properties analysis of a stay cable-damper system in consideration of design and construction factors

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Earthquake Engineering and Engineering Vibration 2014年第2期13卷 317-326页

作者： Dan Danhui Chen Yanyang Xiao Rong Department of Bridge Engineering Tongji University Henan Provincial Communications Planning Survey & Design Institute Co. Ltd

A numerical solution based on the Steffensen stable point iterative method is proposed to resolve the transcendental frequency equation of a stay cable-damper system. The frequency equation, which considers clamped supports and fl exural rigidity of the cable, is intended to investigate the infl uence of the parameters of the cable damper system on its dynamic characteristics. Two factors involved in the design and construction phases, the damping coeffi cient induced by external dampers and the cable tension, are the focus of this study. Their impact on modal frequencies and damping ratios in these two phases of cable-damper systems are investigated by resolving the equation with the proposed solution. It is shown that the damping coeffi cient and cable tension exert more noticeable effects on the modal damping ratios than on the modal frequencies of stay cable-damper systems, and the two factors can serve as design variables in the design phase and as adjustment factors in the construction phase. On the basis of the results, a roadmap for system-level optimal design of stay cable-damper systems that can achieve global optimal vibration suppression for the entire bridge is proposed and discussed.

关键词： cable damper damping coeffi cient cable tension dynamic property optimal design

Experimental study of vibration mitigation of mast arm signal structures with particle-thrust damping based tuned mass damper

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Earthquake Engineering and Engineering Vibration 2019年第1期18卷 219-231页

作者： Zhang Yunfeng Liu Heng Dept.of Civil & Environmental Engineering University of Maryland College Park

Large amplitude vibration of mast arm structures due to wind loads are the primary contributing factor to the reduced fatigue life of signal support structures. To alleviate this problem of wind-induced in-plane vibration of mast arm signal structures, a particle-thrust damping based turned mass damper(PTD-TMD) device is adopted and its damping effect is characterized experimentally. The particle-thrust damping is a passive damping device that does not require electric power and is temperature independent. Based on the calibration test, an equivalent dynamic model of the PTD-TMD device is developed and used for numerical simulation study. The damping effects of this PTD-TMD device on signal support structures was investigated through both numerical analysis and laboratory testing of a 50-ft(15.24 m) mast arm structure including both free vibration and forced vibration tests. The experimental test and numerical study results show that vibration response behavior of mast arm signal support structures can be significantly reduced by installing the PTD-TMD that can increase the critical damping ratio of the mast arm signal structures to 4%. The stress range at the welded connection between the mast arm and traffic pole is also reduced.

关键词： fatigue mast arm signal support structures tuned mass damper vibration

Rotational Friction damper’s Performance for Controlling Seismic Response of High Speed Railway Bridge-Track System

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Computer Modeling in Engineering & Sciences 2019年第9期120卷 491-515页

作者： Wei Guo Chen Zeng Hongye Gou Yao Hu Hengchao Xu Longlong Guo School of Civil Engineering Central South UniversityChangsha410075China National Engineering Laboratory for High Speed Railway Construction Changsha410075China School of Civil Engineering Southwest Jiaotong UniversityChengdu610031China Department of Civil Engineering the University of British ColumbiaVancouver V6T 1Z4Canada.

CRTS-II slab ballastless track on bridge is a unique system in China high speed *** application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge *** bridge system and CRTS-II track system form a complex nonlinear *** investigate the seismic response of high speed railway(HSR)simply supported bridge-track system,nonlinear models of three-span simply supported bridge with piers of different height and CRTS-II slab ballastless track system are *** seismic analysis,it is found that shear alveolar in CRTS-II track system is more prone to be damaged than bridge components,such as piers,girders and *** result shows that the inconsistent displacement of bridge girders is the main cause of the CRTS-II track system’s *** the rotational friction damper(RFD)is adopted,which utilizes the device’s rotation and friction to dissipate seismic *** hysteretic behavior of RFD is studied by numerical and experimental *** prove that RFD can provide good hysteretic energy dissipation ability with stable ***,the analysis of RFD’s influence on seismic response of HSR bridge-track system shows that RFD with larger sliding force is more effective in controlling excessive inconsistent displacement where RFD is installed,though response of other bridge spans could slightly deteriorated.

关键词： Rotational friction damper high speed railway simply supported bridge-track system piers of different height CRTS-II track system seismic response control

Design and experiment of bio-inspired GER fluid damper

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Science China(Information Sciences) 2020年第7期63卷 113-115页

作者： Huayan PU Yining HUANG Yi SUN Min WANG Shujin YUAN Zhen KONG Peipei YANG Liufeng CHU Jinbo WU Yan PENG Shaorong XIE Jun LUO School of Mechatronics Engineering and Automation Shanghai University School of Materials Science and Engineering Shanghai University State Key Laboratory of Mechanical Transmission Chongqing University

Dear editor,With the rapid development of industrial robots,the influence of vibration has been considerably increasing. The consequent demand for vibration suppression in robot systems has become increasingly urgent. The effective vibration suppression can remarkably improve the performance of robots such as operation stability, detective and tracking accuracy, and the security of interaction with the human body.

关键词： GER fluid damper biological muscle robotic systems vibration attenuation

Occurrence of bistable state in squeeze film damper rotor system

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Journal of Harbin Institute of Technology(New Series) 2000年第2期7卷 75-77页

作者：陈照波焦映厚刘占生夏松波蒋书运 School of Power Engineering Harbin Institute of Technology Harbin 150001 China Tsinghua University Beijing 100084 China

Presents the study on the law governing the occurrence of bistable state in the squeeze film damper supported rigid rotor system by theoretical calculations,the way q calculating the bistable state characteristics, the analysis of bistable state characteristics using bearing parameter B and mass eccentricity U as basic parameters, and the ranges of B and U values established, and concludes that the occurrence of bistable state can be avoided provided design parameters are properly selected so that the B and U values are not in the ranges established. This makes it convenient to optimize the squeeze film damper design parameters.

关键词： squeeze film damper bistable state rotor system