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Out-of-plane elastic buckling load and strength design of space truss arch with a rectangular section

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Frontiers of Structural and Civil Engineering 2022年第9期16卷 1141-1152页

作者： Senping WANG Xiaolong LIU Bo YUAN Minjie SHI yanhui wei Space Structures Research Center Guizhou UniversityGuiyang 550025China

The out-of-plane stability of the two-hinged space truss circular arch with a rectangular section is theoretically and numerically investigated in this ***,the flexural stiffness and torsional stiffness of space truss arches are *** calculation formula of out-of-plane elastic buckling loads of the space truss arch is derived based on the classical solution of out-of-plane flexural-torsional buckling loads of the solid web ***,since the classical solution cannot be used for the calculation of the arch with a small rise-span ratio,the formula for out-of-plane elastic buckling loads of space truss arches subjected to end bending moments is *** research of the out-of-plane stability of space truss arches under different load cases shows that the theoretical formula proposed in this paper has good ***,the design formulas to predict the out-of-plane elastoplastic stability strength of space truss arches subjected to the end bending moment and radial uniform load are presented through introducing a normalized slenderness *** assuming that all components of space truss circular arches bear only axial force,the design formulas to prevent the local buckling of chord and transverse tubes are ***,the bearing capacity design equations of space truss arches are proposed under vertical uniform load.

关键词： torsional stiffness strength design elastic buckling space truss arches out-of-plane

Review of interface tailoring techniques and applications to improve insulation performance

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High Voltage 2022年第1期7卷 12-31页

作者： Mingxiao Zhu Jianyi Xue yanhui wei Guochang Li Guanjun Zhang College of New Energy China University of Petroleum(East China)QingdaoChina State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical EngineeringXi'an Jiaotong UniversityXi'anChina Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoChina

Interfaces between different materials,for instance,electrode-dielectrics and vacuum/air/SF6‐insulators and oilpaper,are universal in high‐voltage insulation *** tailoring of the interfacial properties,*** structures,micro‐/nanoscale morphology,the charge injection barrier,trap states,and surface conductivity,is thought to be an effective approach to improve insulation properties such as breakdown and flashover strength,corona/tracking resistance,and *** this article,the authors review recent progress in interface tailoring methods and their application to improve various insulation *** potential application scenarios of interface tailoring in different facilities are first summarised,and the desired insulation properties of various applications are *** tailoring methods are classified as physical/chemical surface modification and surface coating(inorganic,organic and composite),and the features of different techniques are described in *** structure-property relationships between interfacial states and various microscopic parameters such as charge injection barrier,trap distribution and surface conductivity are discussed together with the tailoring mechanisms for different insulation ***,the future development prospects of interface tailoring methods and their applications,***-functional coating and stimuli-response smart coating,are presented.

关键词： coating interface insulation

Effect of matrix resin components on properties of the semi-conductive shielding material for high-voltage cable

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High Voltage 2024年第2期9卷 419-428页

作者： Guochang Li Tianyao Liu Xiaolong Chen yanhui wei Chuncheng Hao Shengtao Li Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

The semi-conductive shielding layer is an important part of the high-voltage cable,playing a role in uniform electric field and reducing the air gap at the *** overall performance of the cable is affected by the semi-conductive shielding layer with different base resin *** matrix resins of ethylene-vinyl acetate(EVA),ethylene-ethyl acrylate(EEA)and ethylene-butyl acrylate(EBA)were used to prepare the semi-conductive shielding materials of CB/EVA,CB/EEA and CB/*** influences of different matrix resins on the chemical,electrical,thermal and mechanical properties of the shielding materials were *** results show that CB has the best dispersion in EBA resin and the worst dispersion in EEA *** temperature in-flection points of CB/EVA,CB/EEA and CB/EBA shielding materials are 90°C,100°C and 110°C,respectively,and the CB/EBA shielding material has the lowest resistivity and the weakest positive temperature coefficient effect at room *** thermal conductivity of all three matrix resins is smaller than that of the shielding material,the thermal conductivity of CB/EVA and CB/EBA shielding materials show a slow increase with temperature,and the CB/EEA shielding material is the least affected by the *** mechanical properties of the three matrix resins and the three shielding materials are EBA>EVA>EEA,among them the stress of CB/EBA shielding material is 31.0 MPa and the strain is 570%.This work has important reference significance for the selection of shielding layer matrix resin and material formulation in engineering applications.

关键词： temperature. resin resins

High level of extra-pair paternity in the socially monogamous Marsh Tits(Poecile palustris)

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Avian Research 2021年第4期12卷 722-726页

作者： Juan Wang yanhui wei Lei Zhang Yiting Jiang Keke Li Dongmei Wan Laboratory of Animal Resource and Epidemic Disease Prevention Department of Life SciencesLiaoning UniversityShenyang 110036China

Background:Extra-pair copulation behavior has been widely studied among socially monogamous *** species revealed high rates of extra-pair *** few of the studies have been carried out in the Asian ***:From 2012 to 2019,we explored the extra-pair paternity of Marsh Tits(Poecile palustris)in Xianrendong National Nature Reserve,Liaoning Province,*** the study,adult Marsh Tits were captured with mist nets and parental birds,with nest-box *** samples were taken from the brachial *** analyses were carried out using nine highly variable microsatellite loci through Cervus 3.0 software and maximum likelihood ***:Forty-nine offspring(15.08%)from 20 nests(45.45%)were the results of extra-pair fertilization out of a total of 325 offspring in 44 *** average extra-pair offspring ratio was 33.54%,with a set varying from 11.11 to 71.43%.Nine extra-pair fathers had been successfully identified,four of whom were the close neighbors of the focus nest while the nests of the remaining five were relatively *** significant difference was found in the genetic similarity between the social and extra-pair mates of the female,nor in the heterozygosis among the maternal ***:In general,our study proved that the extra-pair paternity in Marsh Tits and its extra-pair mating is independent of the genetic compatibility *** complements the understudied bird's extra-pair paternity in Asian area and contributes to the comprehensive insight of birds'extra-pair paternity behaviors.

关键词： Extra-pair paternity Genetic compatibility hypothesis Marsh Tits Microsatellite

Planar Serial Manipulator Motion Synthesis

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Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 49-55页

作者： yanhui wei Han Han Zepeng Wang Xin Liu Guangchun Li College of Automation Harbin Engineering University

： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target, it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspaee boundary method, an expressing method of the polar coordinate form of work space is then introduced. Finally, according to the form of plane trajectory planning for obstacle avoidance problem, the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.

关键词： planar serial manipulators inverse kinematics workspace trajectory planning vector projection

Research progress of semiconductive shielding layer of HVDC cable

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High Voltage 2020年第1期5卷 1-6页

作者： yanhui wei Wang Han Guochang Li Qingquan Lei Mingli Fu Chuncheng Hao Guanjun Zhang Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoPeople's Republic of China State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anPeople's Republic of China China South Power Grid International Co. LtdGuangzhouPeople's Republic of China

As an indispensable part of high-voltage direct current(HVDC)cable,the semiconductive shielding layer plays the role of uniforming electric field in the ***,cable shielding materials>35 kV mainly rely on foreign imports in China,which belongs to the technical weak issues in the field of electrical *** present,there are few systematic reports on semiconductive shielding material of HVDC *** the work,the mechanisms of charge conduction and thermal conduction of semiconductive material have been *** of raw material,carbon black content and the second conductive filler on the resistance characteristics of the semiconductive layer,the charge accumulation characteristics of the insulating layer and the interface characteristics have been studied.A kind of semiconductive layer as a high voltage terminal charge emission method has been proposed to study charge emission from the semiconducting layer to the insulation *** work can provide theoretical guidance for the research of semiconductive shielding materials.

关键词： conductive layer conduction

Effect of temperature on electric-thermal properties of semiconductive shielding layer and insulation layer for high-voltage cable

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High Voltage 2021年第5期6卷 805-812页

作者： yanhui wei Mingyue Liu Xuejing Li Guochang Li Naiyi Li Chuncheng Hao Qingquan Lei Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoChina State Grid Zhejiang Electric Power Co. LtdResearch InstituteHangzhouChina

A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage *** electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect the overall insulation performance of the *** physicochemical performances of semi‐conductive composites are firstly analysed ***,electric‐thermal properties of the semi‐conductive layer and insulation layer are *** experimental results show that the thermal conductivity of the commercial semi‐conductive layer is about twice that of the insulation layer,owing to the effect of carbon *** thermal expansion coefficient of the insulation layer rises from 1.86×10^(−4)/K at 25℃ to 3.20×10^(−4)/K at 90℃.By contrast,the semi‐conductive layer begins to slowly decline at a certain temperature,and decreases signif-icantly to 2.25×10^(−4)/K at 80℃,owing to the effect of ethylene‐vinyl acetate copolymer(EVA).The electrical experiments show that the resistivity of semi‐conductive composite gradually rises with an increase in temperature,and gradually declines with an increase in the carbon black *** dc breakdown strength of the composite structure of the semi‐conductive layer/insulation layer decreases significantly with an increase in tem-perature,decreasing from 307 kV/mm at 25℃ to 203 kV/mm at 90℃.At four typical temperatures,the breakdown strength reaches the maximum value when the carbon black content is 25 *** is about 15%and 19%higher than carbon black contents of 20 and 30 *** findings have reference significance for high‐voltage cable breakdown fault analysis and material selection in cable design.

关键词： composite insulation composites

DC breakdown characteristics of XLPE/BNNS nanocomposites considering BN nanosheet concentration,space charge and temperature

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High Voltage 2020年第3期5卷 280-286页

作者： Guochang Li Xuguang Zhou Xuejing Li yanhui wei Chuncheng Hao Shengtao Li Qingquan Lei Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoPeople's Republic of China State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anPeople's Republic of China

Breakdown failure in insulation material is one of the key problems that threaten the safe operation of high-voltage direct current *** this work,the effect of boron nitride nanosheets(BNNSs)concentration,space charge and temperature on DC breakdown strength have been ***-linked polyethylene(XLPE)/BNNS nanocomposites were prepared by the melt blending method,and the basic characteristics of nanoparticles and composite were *** experimental results indicate that DC breakdown strength of nanocomposite can be effectively improved when a small amount of BN nanosheet is doped into the *** breakdown strength of the sample reaches the maximum value of 407.52 kV/mm when BNNS content is 0.5 wt%,which is about 33%higher than that of pure ***,the effect of space charge on the breakdown of nanocomposites has been studied by pre-injecting *** the samples with different BNNS contents,all the breakdown strength present ascending trend when the polarity of the applied voltage is the same as that of the pre-injected ***,it can be found that the breakdown strength of the XLPE/BNNSs composite decreases significantly at 50°C,which is due to more charge accumulation at 50°*** reaches 2.06×10^(−8)C which increases by about 2.2 times than the room temperature.

关键词： strength charge characteristics

Obstacle Avoidance Method for a Redundant Manipulator Based on a Configuration Plane

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Journal of Beijing Institute of Technology 2019年第3期28卷 456-468页

作者： yanhui wei Yanfeng Zhao Jing Liu Shenggong Hao Lixue Xu Qiang Zhu Anqi Wang College of Automation Harbin Engineering University

This paper presents a novel approach of obstacle avoidance for redundant manipulators, which is challenging with the considerations of the building of universal kinematics, the formation of dynamics, and the generation of trajectories. A universal approach to deal with obstacle avoidance for the redundant manipulator, that is based on the configuration plane, is presented. The paper also examines common serial robot configurations and introduces a method for classification, partitioning, simplification, and forms of expression used in the workspace to define the configuration plane. This relatively new method is combined with a weighted space vector method to match the configuration plane and solve the inverse kinematics problem. The proposed planner is demonstrated with examples, in which the proposed planner is shown to be capable of providing a smoother trajectory.

关键词： redundant manipulator configuration plane trajectory generation obstacle avoidance space vector