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Passive structural control with inerters for a floating offshore wind turbine 36

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Passive structural control with inerters for a floating offs...

第36届中国控制会议

作者： Yinlong Hu Michael z.q.chen College of Energy and Electrical Engineering Hohai University School of Automation Nanjing University of Science and Technology

ISBN: (纸本)9781538629185

This paper investigates an inerter-based passive structural control problem for a floating offshore wind turbine to reduce the loads induced by wind and *** proposed inerter-based system is composed of a passive spring,a damper,and a parallel-connected passive network.A parameter tuning method by maximizing the minimal modal damping of a linear design model is proposed,and the nonlinear wind turbine simulation code FAST-SC is *** simulations are conducted to show the effectiveness and the performance benefits of the proposed inerter-based structural control *** is shown that the proposed inerter-based system can effectively reduce the wind-and wave-induced loads compared with the conventional spring-damper system.

关键词： Inerter offshore wind turbine floating platform FAST inerter-based dynamic vibration absorber(IDVA)

Irradiation-induced homogeneous plasticity in amorphous/amorphous nanolaminates

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Journal of Materials Science & Technology 2020年第22期54卷 70-77页

作者： L.Huang z.q.chen P.Huang X.K.Meng F.Wang State Key Laboratory for Mechanical Behavior of Material School of Materials Science and EngineeringXi'an Jiaotong UniversityXi'an710049China Institute of Materials Engineering National Laboratory of Solid State MicrostructuresCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'an710049China

Achieving homogeneous plastic deformation in metallic glasses is a long-standing goal yet to be solved in materials science. Here we investigate the effect of ion irradiation on the plastic deformation behavior of zrCu/zrCuNiAlSi amorphous/amorphous nanolaminates(A/ANLs) via nanoindentation testing. The experimental results indicate a dramatic change in deformation mode from multiple shear banding events to homogeneous compressive deformation before and after ion irradiation on the A/ANLs in the areas underneath the indenter. Ion irradiation-induced changes of both fraction and distribution of free volume inside each constituent layer and interfacial state in the A/ANLs may be responsible for the unusual homogeneous deformation behavior. Our results suggest that the mechanical property of A/ANLs could be modified by tuning both the inner and interfacial structure via ion irradiation.

关键词： Metallic glasses Ion irradiation Plastic deformation Nanolaminates Interface

Corrosion protection of NiNb metallic glass coatings for 316SS by magnetron sputtering

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Journal of Materials Science & Technology 2021年第20期79卷 88-98页

作者： L.Jiang z.q.chen H.B.Lu H.B.Ke Y.Yuan Y.M.Dong X.K.Meng School of Chemistry and Life Sciences Suzhou University of Science and TechnologySuzhou 215009China Institute of Materials Engineering National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210009China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China Institute of Materials Engineering Nanjing UniversityNantong 226019China College of Chemistry and Chemical Engineering Nantong UniversityNantong 226019China

Metallic glasses(MGs)appear as promising anti-corrosion coating materials due to their microstructural and physicochemical ***,we proposed magnetron sputtered NiNb thin film MG coatings(MGCs)with different structures and compositions for corrosion protection of 316 stainless steel in an aggressive saline *** properties of monolayered Ni_(50)Nb_(50) and Ni_(60)Nb_(40),as well as the multilayered Ni_(50)Nb_(50)/Ni_(60)Nb_(40)(at.%)MGCs,were characterized in terms of morphology and microstructural properties,as well as the anticorrosion *** the NiNb MGCs presented compact structure and the monolayered coatings exhibited preferable adhesion properties in comparison with the multilayered *** electrochemical tests and XPS results imply that the monolayered Ni_(50)Nb_(50) MGC with high Nb content resisted corrosion mainly due to the formation of stable passive film that contained abundant Nb_(2)O_(5) species,whereas the Ni_(60)Nb_(40) MGC with high Ni content showed week corrosion protection performance during long-term service due to the dissolution of Ni cations and the devastation of the coating *** with bit worse adhesion and more vulnerable Ni_(60)Nb_(40) layers,the multilayered Ni_(50)Nb_(50)/Ni_(60)Nb_(40) MGC possessed comparable corrosion resistance with the monolayered Ni_(50)Nb_(50) MG coating,which remained stable even after 32 days of *** performance should be ascribed to the combined eff;ect of the repassivation property for the sub-layers,the hindrance of propagation paths of micro-defects,and the obstruction of corrosive species by interfaces in the multilayered coating.

关键词： Magnetron sputtering NiNb Metallic glasses Multilayer Corrosion protection

Robust Stabilization of a Class of Nonlinear Systems with Uncertain Parameters Based on CLFs

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Robust Stabilization of a Class of Nonlinear Systems with Un...

第三十届中国控制会议

作者： Michael z.q.chen Department of Mechanical Engineering The University of Hong Kong

＜正＞This paper is considered with the robust stabilization problem of a class of nonlinear systems with bounded uncertain time-invariant parameters.A robust control Lyapunov function（RCLF） is introduced for the considered *** on the RCLF,a globally asymptotically stabilizing controller is then *** proposed controller is robust under the variant of system *** the applications of the proposed scheme,the stabilization of uncertain feedback linearizable systems and the unified chaotic system are investigated,respectively.A numerical example on the unified chaotic system is also provided to illustrate the effectiveness of the presented method.

关键词： Stabilization Nonlinear systems Robust control Lyapunov functions Parameter uncertainty Feedback linearizable systems Chaotic systems

Interface dominated deformation transition from inhomogeneous to apparent homogeneous mode in amorphous/amorphous nanolaminates

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Journal of Materials Science & Technology 2022年第4期99卷 178-183页

作者： z.q.chen M.C.Li J.S.Cao F.C.Li S.W.Guo B.A.Sun H.B.Ke W.H.Wang Songshan Lake Materials Laboratory Dongguan 523808PR China Institute of Physics Chinese Academy of SciencesBeijing 100190PR China Institute of Materials Engineering Nanjing UniversityNantong 226019PR China School of Physics Science and Technology Xinjiang UniversityXinjiang 830046PR China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049PR China State Key Laboratory for Mechanical Behavior of Material Xi'an Jiaotong UniversityXi’an 710049PR China

The amorphous/amorphous nanolaminates(A/ANLs)have aroused great attentions owing to their tunable structure and enhanced mechanical ***,the plastic deformation mechanism of A/ANLs have yet been ***,we systematically examined the mechanical properties and deformation behavior of series of NiNb/zrCuNi Al A/ANLs via nanoindentaion *** was found that both the amount and morphology of amorphous/amorphous interface(A/AIs)played crucial roles in the plastic deformation of A/*** and straighter A/AIs facilitated multiple shear banding deformation,of which the hardness increased with decreasing layer thickness,as the A/AIs hindered the propagation of shear bands(SBs).Whilst,more and wavier A/AIs promoted homogeneous deformation,of which the hardness stayed at a much lower value and was relatively irrelevant with the layer thickness,for the promoted activation of shear transformation zones by A/*** results provide guidance for modifying the mechanical properties of amorphous alloys with interface engineering design.

关键词： Amorphous alloys Nanolaminates Shear bands Hardness Interface

Dynamic Adjustment of Electric Spring Voltage Compensation Range Based on Fixed Series Compensation

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Dynamic Adjustment of Electric Spring Voltage Compensation R...

第40届中国控制会议

作者： Yun zou Michael z.q.chen School of Automation Nanjing University of Science and Technology

This paper proposes a new control strategy to improve the effective voltage compensation range of electric springs（ES） under reactive compensation modes. The influence of line impedance, including its resistive part and inductive part, on ES regulation ability is analyzed, which shows that the compensation range of ES is more sensitive to the inductive part of the transmission line impedance than the resistive part. Through the introduction of a fixed series compensation（FSC） device, only the reactance of the transmission line impedance is changed without changing the line voltage level and topology structure, thus the improvement of ES voltage regulating capacity is realized. Simulation results are provided to verify the correctness of the analysis and the proposed control strategy.

关键词： Electric Spring(ES) Line Impedance Voltage Control Fixed Series Compensation Smart Grid

Structural control of floating offshore wind turbines with inerter-based low-order mechanical networks

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Structural control of floating offshore wind turbines with i...

第40届中国控制会议

作者： zengmei Li Michael z.q.chen Yinlong Hu School of Automation Nanjing University of Science and Technology College of Energy and Electrical Engineering Hohai University

This paper investigates the load mitigation problem for a barge-type floating offshore wind turbine with inerterbased structural control, where a tuned mass damper and an inerter-based mechanical network are employed. The inerter-based mechanical network is the controller to be designed via the fixed-structure method and the network synthesis method. Due to the influence of the wind turbine structure on the wind and wave inputs, improved wind and wave models are proposed. Then by solving an optimization problem with the proposed performance objective function, better element parameters can be obtained. It is shown that the tower-top fore-aft deflection and the tower bottom bending moment of the wind turbine are decreased while the TMD stroke is increased by using an inerter-based low-order mechanical network as controller. After analyzing the performance of different inerter-based low-order mechanical networks, it is found that the controller configurations with an inerter and a spring in series are more conducive to the reduction of the tower-top fore-aft deflection. In addition, the results show that more effective mechanical network configurations for reducing the tower-top fore-aft deflection can be obtained by using the network synthesis method. Finally, a nonlinear aero-elastic simulation tool for wind turbines called FAST-SC is used to verify the above conclusions obtained by a simplified linear model.

关键词： Inerter Objective function Fixed-structure method Network synthesis method

Hardening and toughening effects of intermediate nanosized structures in a confined amorphous alloy film

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Journal of Materials Science & Technology 2022年第23期118卷 44-53页

作者： z.q.chen M.C.Li X.Tong Y.zhao J.Y.Xie S.W.Guo P.Huang F.Wang H.B.Ke B.A.Sun W.H.Wang Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China Xinjiang Key Laboratory of Solid State Physics and Devices and School of Physical Science and Technology Xinjiang UniversityXinjiangUrumqi 830046China Key Laboratory of LCR Materials and Devices of Yunnan Province School of Materials and EnergyYunnan UniversityKunming 650091China State-Key Laboratory for Mechanical Behavior of Material Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an 710049China National Demonstration Center for Experimental Mechanics Education Xi’an Jiaotong UniversityXi’an 710049China

The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STzs).Yet,the bridge between the mesoscopic SBs and the atomic-scale STzs remains poorly *** this work,through thermally activating pronouncedβrelaxations in the well-designed crystalline-layer confined amorphous(CLCA)Ni W alloy films,we experimentally captured and observed an intermediate nanosized structure termed as“nano shear bands”(NSBs)with a typical size of 1–2 nm in thickness and5–10 nm in *** influences of such NSB structures on the macroscale deformation behavior were systematically *** was found that NSBs lead to both hardening and toughening effects for the CLCA films,as they promote multiple and controlled shear banding deformation,which results in enhanced *** intermediate NSB structure could connect the microstructural characteristics and macroscopic plasticity in amorphous alloys and may provide new insights for understanding the microscopic deformation mechanism of amorphous alloys as well as tuning/designing their properties.

关键词： Amorphous alloys Nano shear band Hardening Toughening Crystallization

Structural control for a barge-type floating offshore wind turbine with a skyhook inerter configuration

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Structural control for a barge-type floating offshore wind t...

第32届中国控制与决策会议

作者： Yinlong Hu Jianing Wang zhaoyan Wang Michael z.q.chen College of Energy and Electrical Engineering Hohai University School of Automation Nanjing University of Science and Technology

This paper studies the wind and wave-induced structural load mitigation problem for a floating offshore wind turbine with a barge platform,where a tuned mass damper(TMD) with a skyhook inerter configuration is *** skyhook inerter is intended to virtually increase the mass of the TMD,which will be demonstrated that the structural loads can be effectively reduced by increasing the mass of the *** simulations demonstrate that the application of a skyhook inerter system can reduce the load of a barge-type floating offshore wind turbine to some ***-active inerters are adopted to realize the skyhook inerter configuration,where two control laws,that is the on-off control and the continuous control,are applied for the semi-active inerter to approximate the skyhook ***,the improvement of overall performance is not significant in numerical simulations,indicating that although the ideal skyhook inerter can effectively improve the performance for the floating offshore wind turbine,its semi-active realizations by using semi-active inerter in associated with the on-off control and the continuous control have very limited performance improvement.

关键词： Inerter Skyhook control Offshore wind turbine Semi-active control Tuned mass damper