期刊文献+
共找到44,496篇文章
< 1 2 250 >
每页显示 20 50 100
Research on the monitoring system for induced voltage and ground current of 27.5 kV cable sheath in railways
1
作者 Zehui Zhang Qian Huang +3 位作者 Lewen Li Dan Li Xueping Luo Xiaohong Zeng 《Railway Sciences》 2024年第5期622-635,共14页
Purpose–The purpose of this study is to address the deficiency in safety monitoring technology for 27.5 kV high-voltage cables within the railway traction power supply by analyzing the grounding methods employed in h... Purpose–The purpose of this study is to address the deficiency in safety monitoring technology for 27.5 kV high-voltage cables within the railway traction power supply by analyzing the grounding methods employed in high-speed railways and developing an effective monitoring solution.Design/methodology/approach–Through establishing a mathematical model of induced potential in the cable sheath and analyzing its influencing factors,the principle of grounding current monitoring is proposed.Furthermore,the accuracy of data collection and alarm function of the monitoring equipment were verified through laboratory simulation experiments.Finally,through practical application in the traction substation of the railway bureau on site,a large amount of data were collected to verify the stability and reliability of the monitoring system in actual environments.Findings–The experimental results show that the designed monitoring system can effectively monitor the grounding current of high-voltage cables and respond promptly to changes in cable insulation status.The system performs excellently in terms of data collection accuracy,real-time performance and reliability of alarm functions.In addition,the on-site trial results further confirm the accuracy and reliability of the monitoring system in practical applications,providing strong technical support for the safe operation of highspeed railway traction power supply systems.Originality/value–This study innovatively develops a 27.5kV high-voltage cable grounding current monitoring system,which provides a new technical means for evaluating the insulation status of cables by accurately measuring the grounding current.The design,experimental verification and application of this system in high-speed railway traction power supply systems have demonstrated significant academic value and practical significance,contributing innovative solutions to the field of railway power supply safety monitoring. 展开更多
关键词 Railway 27.5 kV high-voltage cable Online monitoring system Grounding current Induced potential
下载PDF
Nonlinear dynamical response of high-voltage transmission lines based on cable dropping 被引量:1
2
作者 夏开全 刘云 钱振东 《Journal of Southeast University(English Edition)》 EI CAS 2009年第1期52-56,共5页
In order to study the dynamic response of high-voltage transmission lines under mechanical failure, a finite element model of a domestic 500-kV high-voltage transmission line system is established. The initial equilib... In order to study the dynamic response of high-voltage transmission lines under mechanical failure, a finite element model of a domestic 500-kV high-voltage transmission line system is established. The initial equilibrium condition of the coupling system model is verified by nonlinear static analysis. The transient dynamic analysis method is proposed to analyze the variation law of dynamic response under cable or insulator rupture, and the dynamic response of structural elements next to the broken span is calculated. The results show that upper crossarm cable rupture has no effect on cable tension at adjacent suspension points, but it has a significant influence on tension in the insulator and the tower component of the upper crossarm next to the broken span. The peak tension in the conductor of the upper crossarm at the suspension point exceeds the design value under insulator rupture. Insulator rupture has no effect on the tower component of the upper crossarm, but it has a significant influence on insulator tension of the upper crossarm. Insulator rupture should be taken into account in the design of overhead transmission lines. The research results can provide a theoretical basis for the design of transmission lines. 展开更多
关键词 high-voltage transmission line transient response cable dropping numerical simulation finite element method
下载PDF
Unique double-layer solid electrolyte interphase formed with fluorinated ether-based electrolytes for high-voltage lithium metal batteries 被引量:2
3
作者 Ruo Wang Jiawei Li +11 位作者 Bing Han Qingrong Wang Ruohong Ke Tong Zhang Xiaohu Ao Guangzhao Zhang Zhongbo Liu Yunxian Qian Fangfang Pan Iseult Lynch Jun Wang Yonghong Deng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期532-542,I0012,共12页
Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the... Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries. 展开更多
关键词 Lithium metal batteries high-voltage layered oxides Fluorinated ether-based electrolytes Solid electrolyte interphase Cathode electrolyte interphase
下载PDF
Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables 被引量:2
4
作者 SUN Xiaoming WANG Jian +6 位作者 ZHAO Wenchao MING Jiang ZHANG Yong LI Zhihu MIAO Chengyu GUO Zhibiao HE Manchao 《Journal of Mountain Science》 SCIE CSCD 2024年第1期236-251,共16页
The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and ... The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway. 展开更多
关键词 Kilometre-deep mine Fault Mining roadway Failure mechanism Pre-splitting cutting roof High pre-stress NPR anchor cable
下载PDF
Online Monitoring Method Based on Locus-analysis for High-voltage Cable Faults 被引量:1
5
作者 Wei Zhao Xiangyang Xia +4 位作者 Mingde Li Hai Huang Shanqiu Chen Ruiqi Wang Yan Liu 《Chinese Journal of Electrical Engineering》 CSCD 2019年第3期42-48,共7页
Online diagnosis methods for high-voltage(HV)cable faults have been extensively studied.Power cable fault monitoring is not accurate,and the degree of data fusion analysis of current methods is insufficient.To address... Online diagnosis methods for high-voltage(HV)cable faults have been extensively studied.Power cable fault monitoring is not accurate,and the degree of data fusion analysis of current methods is insufficient.To address these problems,an online monitoring method based on the locus-analysis for HV cable faults is developed.By simultaneously measuring two circulating currents in a coaxial cable,a two-dimensional locus diagram is drawn.The fault criteria and database are established to detect the fault by analyzing the changes of the locus characteristic parameters.A cross-connected grounding simulation model of a high-voltage cable is developed,and several faults at different locations are simulated.Fault identification is established based on the changes in the long axis,short axis,eccentricity,and tilt angle of the track.The simulation and field experiments show that this method can provide an increased amount of fault-monitoring reference information,which can improve the monitoring accuracy and provide a new approach to cable fault monitoring. 展开更多
关键词 Locus-analysis high-voltage cable online monitoring characteristic parameters
原文传递
Electric field and force characteristic of dust aerosol particles on the surface of high-voltage transmission line
6
作者 刘滢格 李兴财 +2 位作者 王娟 马鑫 孙文海 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期368-378,共11页
High-voltage transmission lines play a crucial role in facilitating the utilization of renewable energy in regions prone to desertification. The accumulation of atmospheric particles on the surface of these lines can ... High-voltage transmission lines play a crucial role in facilitating the utilization of renewable energy in regions prone to desertification. The accumulation of atmospheric particles on the surface of these lines can significantly impact corona discharge and wind-induced conductor displacement. Accurately quantifying the force exerted by particles adhering to conductor surfaces is essential for evaluating fouling conditions and making informed decisions. Therefore, this study investigates the changes in electric field intensity along branched conductors caused by various fouling layers and their resulting influence on the adhesion of dust particles. The findings indicate that as individual particle size increases, the field strength at the top of the particle gradually decreases and eventually stabilizes at approximately 49.22 k V/cm, which corresponds to a field strength approximately 1.96 times higher than that of an unpolluted transmission line. Furthermore,when particle spacing exceeds 15 times the particle size, the field strength around the transmission line gradually decreases and approaches the level observed on non-adhering surface. The electric field remains relatively stable. In a triangular arrangement of three particles, the maximum field strength at the tip of the fouling layer is approximately 1.44 times higher than that of double particles and 1.5 times higher compared to single particles. These results suggest that particles adhering to the transmission line have a greater affinity for adsorbing charged particles. Additionally, relevant numerical calculations demonstrate that in dry environments, the primary adhesion forces between particles and transmission lines follow an order of electrostatic force and van der Waals force. Specifically, at the minimum field strength, these forces are approximately74.73 times and 19.43 times stronger than the gravitational force acting on the particles. 展开更多
关键词 high-voltage current electric field aerosol particles force characteristic
下载PDF
How do high-voltage cathode and PEO electrolyte get along well?EIS analysis mechanism&potentiometric control strategy
7
作者 Xiaodong Bai Chaoliang Zheng +4 位作者 Heng Zhang Jian Liu Panpan Wang Baojia Xia Jianling Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期424-436,共13页
PEO-based all-solid-state electrolytes are extensively utilized and researched owing to their exceptional safety,low-mass-density,and cost-effectiveness.However,the low oxidation potential of PEO makes the interface p... PEO-based all-solid-state electrolytes are extensively utilized and researched owing to their exceptional safety,low-mass-density,and cost-effectiveness.However,the low oxidation potential of PEO makes the interface problem with the high-voltage cathode extremely severe.In this work,the impedance of PEO-based all-solid-state batteries with high-voltage cathode(NCM811)was studied at different potentials.The Nyquist plots displayed a gyrate arc at low-frequencies for NCM811/PEO interface.Based on the kinetic modeling,it was deduced that there is a decomposition reaction of PEO-matrix in addition to de-embedded reaction of NCM811,and the PEO intermediate product(dehydra-PEO)adsorbed on the electrode surface leading to low-frequency inductive arcs.Furthermore,the distribution of relaxation time shows the dehydra-PEO results in the kinetic tardiness of the charge transfer process in the temporal dimension.Hence,an artificial interface layer(CEI_(x))was modified on the surface of NCM811 to regulate the potential of cathode/electrolyte interface to prevent the high-voltage deterioration of PEO.NCM/CEI_(x)/PEO batteries exhibit capacity retentions of 96.0%,84.6%,and 76.8%after undergoing 100 cycles at cut-off voltages of 4.1,4.2,and 4.3 V,respectively.Therefore,here the failure mechanism of high-voltage PEO electrolyte is investigated by EIS and a proposed solving strategy is presented. 展开更多
关键词 PEo-based electrolyte high-voltage cathode Electrochemical impedance spectroscopy Mechanism research Electrochemical characteristic
下载PDF
Degradation analysis and doping modification optimization for high-voltage P-type layered cathode in sodium-ion batteries
8
作者 Bao Zhang Yi Zhao +5 位作者 Minghuang Li Qi Wang Lei Cheng Lei Ming Xing Ou Xiaowei Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期1-9,I0002,共10页
Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning the... Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently explored.In this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox reactions.By introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel interfaces.The Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 V.This investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides. 展开更多
关键词 Soidum ion batteries Layer cathode materials P-TYPE high-voltage performance Degradation analysis
下载PDF
Understanding the failure mechanism towards developing high-voltage single-crystal Ni-rich Co-free cathodes
9
作者 Jixue Shen Bao Zhang +4 位作者 Changwang Hao Xiao Li Zhiming Xiao Xinyou He Xing Ou 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第6期1045-1057,共13页
Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehic... Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehicles(EVs)sales,which is considered as the most promising nextgeneration cathode material for lithium-ion batteries(LIBs).However,the lack of deep understanding on the failure mechanism of NM has seriously hindered its application,especially under the harsh condition of high-voltage without sacrifices of reversible capacity.Herein,singlecrystal LiNi_(0.8)Mn_(0.2)O_(2) is selected and compared with traditional LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM),mainly focusing on the failure mechanism of Cofree cathode and illuminating the significant effect of Co element on the Li/Ni antisite defect and dynamic characteristic.Specifically,the presence of high Li/Ni antisite defect in NM cathode easily results in the extremely dramatic H2/H3 phase transition,which exacerbates the distortion of the lattice,mechanical strain changes and exhibits poor electrochemical performance,especially under the high cutoff voltage.Furthermore,the reaction kinetic of NM is impaired due to the absence of Co element,especially at the single-crystal architecture.Whereas,the negative influence of Li/Ni antisite defect is controllable at low current densities,owing to the attenuated polarization.Notably,Co-free NM can exhibit better safety performance than that of NCM cathode.These findings are beneficial for understanding the fundamental reaction mechanism of single-crystal Ni-rich Co-free cathode materials,providing new insights and great encouragements to design and develop the next generation of LIBs with low-cost and high-safety performances. 展开更多
关键词 Li/Ni antisite defect Dynamic characteristic high-voltage SINGLE-CRYSTAL Ni-rich Co-free cathodes Lithium-ion batteries
下载PDF
High-Voltage and Fast-Charging Lithium Cobalt Oxide Cathodes: From Key Challenges and Strategies to Future Perspectives
10
作者 Gongrui Wang Zhihong Bi +3 位作者 Anping Zhang Pratteek Das Hu Lin Zhong-Shuai Wu 《Engineering》 SCIE EI CAS CSCD 2024年第6期105-127,共23页
Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics.However,the lithiu... Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable electronics.However,the lithium ion(Li+)-storage performance of the most commercialized lithium cobalt oxide(LiCoO_(2),LCO)cathodes is still far from satisfactory in terms of high-voltage and fast-charging capabilities for reaching the double-high target.Herein,we systematically summarize and discuss high-voltage and fast-charging LCO cathodes,covering in depth the key fundamental challenges,latest advancements in modification strategies,and future perspectives in this field.Comprehensive and elaborated discussions are first presented on key fundamental challenges related to structural degradation,interfacial instability,the inhomogeneity reactions,and sluggish interfacial kinetics.We provide an instructive summary of deep insights into promising modification strategies and underlying mechanisms,categorized into element doping(Li-site,cobalt-/oxygen-site,and multi-site doping)for improved Li+diffusivity and bulkstructure stability;surface coating(dielectrics,ionic/electronic conductors,and their combination)for surface stability and conductivity;nanosizing;combinations of these strategies;and other strategies(i.e.,optimization of the electrolyte,binder,tortuosity of electrodes,charging protocols,and prelithiation methods).Finally,forward-looking perspectives and promising directions are sketched out and insightfully elucidated,providing constructive suggestions and instructions for designing and realizing high-voltage and fast-charging LCO cathodes for next-generation double-high LIBs. 展开更多
关键词 Lithium cobalt oxide High energy/power density Fast-charging high-voltage Lithium-ion battery
下载PDF
Seismic stability of expansive soil slopes reinforced by anchor cables using a modified horizontal slice method
11
作者 Wang Long Chen Guoxing +3 位作者 Hu Wei Zhou Enquan Feng Jianxue Huang Anping 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期377-387,共11页
Earthquake-induced slope failures are common occurrences in engineering practice and pre-stressed anchor cables are an effective technique in maintaining slope stability,especially in areas that are prone to earthquak... Earthquake-induced slope failures are common occurrences in engineering practice and pre-stressed anchor cables are an effective technique in maintaining slope stability,especially in areas that are prone to earthquakes.Furthermore,the soil at typical engineering sites also exhibit unsaturated features.Explicit considerations of these factors in slope stability estimations are crucial in producing accurate results.In this study,the seismic responses of expansive soil slopes stabilized by anchor cables is studied in the realm of kinematic limit analysis.A modified horizontal slice method is proposed to semi-analytically formulate the energy balance equation.An illustrative slope is studied to demonstrate the influences of suction,seismic excitations and anchor cables on the slope stability.The results indicate that the stabilizing effect of soil suction relates strongly to the seismic excitation and presents a sine shape as the seismic wave propagates.In higher and steeper slopes,the stabilizing effect of suction is more evident.The critical slip surface tends to be much more shallow as the seismic wave approaches the peak and vice versa. 展开更多
关键词 limit analysis expansive soil slope matric suction anchor cable pseudo-dynamic analysis
下载PDF
A new deformable cable for rock support in high stress tunnel:Steel pipe shrinkable energy-absorbing cable
12
作者 Xuezhen Wu Mingzhu Zhao +5 位作者 Qing Ye Yujing Jiang Tao Deng Hanfang Zheng Gang Wang Zhenchang Guan 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第8期1083-1093,共11页
High stress in surrounding rock will lead to serious problems,e.g.,rock burst in hard rock and large deformation in soft rock.The applied support system under high in-situ stress conditions should be able to carry hig... High stress in surrounding rock will lead to serious problems,e.g.,rock burst in hard rock and large deformation in soft rock.The applied support system under high in-situ stress conditions should be able to carry high load and also accommodate large deformation without experiencing severe damage.In this paper,a specially designed energy-absorbing component for rock bolt and cable that can solve the above problems was proposed.The energy-absorbing component can provide support resistance by plastic deformation of the metal including constraint annulus and compression pipe.For practical engineering,two forms were proposed.One was installed in the surrounding rock by reaming,and the other was installed directly outside the surrounding rock.During the dilation of the surrounding rock,the relative displacement of constraint annulus and compression pipe occurs,resulting in deformation resistance.Deformation resistance is transmitted to the rock bolt or cable,providing support resistance.The lab test and numerical simulation showed that the energy-absorbing component can perfectly achieve the large deformation effect,the deformation amount is as high as 694 mm,and the bearing capacity is stable at 367 kN.The field application tests were carried out in the mining roadway of Xinjulong coal mine,and the results showed that the new type of cable can ensure itself not to break under the condition of large deformation of the surrounding rock.The energy-absorbing component has the superiorities of performing large constant resistance and controllable deformation to effectively control the unpredictable disasters such as large deformation in soft rock and rock burst in hard rock encountered in deep strata. 展开更多
关键词 Energy-absorbing cable Numerical simulation Lab test Load capacity Ultimate displacement
下载PDF
Mechanism of high-preload support based on the NPR anchor cable in layered soft rock tunnels
13
作者 SUI Qiru HE Manchao +3 位作者 SHI Mengfan TAO Zhigang ZHAO Feifei ZHANG Xiaoyu 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1403-1418,共16页
The control of large deformation problems in layered soft rock tunnels needs to solve urgently.The roof problem is particularly severe among the deformation issues in tunnels.This study first analyzes the asymmetric d... The control of large deformation problems in layered soft rock tunnels needs to solve urgently.The roof problem is particularly severe among the deformation issues in tunnels.This study first analyzes the asymmetric deformation modes in layered soft rock tunnels with large deformations.Subsequently,we construct a mechanical model under ideal conditions for controlling the roof of layered soft rock tunnels through high preload with the support of NPR anchor cables.The prominent roles of long and short NPR anchor cables in the support system are also analyzed.The results indicate the significance of high preload in controlling the roof of layered soft rock tunnels.The short NPR anchor cables effectively improve the integrity of the stratified soft rock layers,while the long NPR anchor cables effectively mobilize the self-bearing capacity of deep-stable rock layers.Finally,the high-preload support method with NPR anchor cables is validated to have a good effect on controlling large deformations in layered soft rock tunnels through field monitoring data. 展开更多
关键词 Tunnel engineering Soft rock High-preload support NPR anchor cables
下载PDF
Global Dynamic Responses and Progressive Failure of Submerged Floating Tunnel Under Cable Breakage Conditions
14
作者 ZHOU Xiang-bo QIAO Dong-sheng +3 位作者 WANG Ming TANG Guo-qiang LU Lin OU Jinping 《China Ocean Engineering》 SCIE EI CSCD 2024年第4期676-688,共13页
The Submerged Floating Tunnel(SFT)relies on a tensioned mooring system for precise positioning.The sudden breakage of a single cable can trigger an immediate alteration in the constraint conditions of the tube,inducin... The Submerged Floating Tunnel(SFT)relies on a tensioned mooring system for precise positioning.The sudden breakage of a single cable can trigger an immediate alteration in the constraint conditions of the tube,inducing a transient heave response within the structure along with a transient increase in cable tension experienced by adjacent cables.In more severe cases,this may even lead to a progressive failure culminating in the global destruction of the SFT.This study used ANSYS/AQWA to establish a numerical model of the entire length SFT for the hydrodynamic response analysis,and conducted a coupled calculation of the dynamic responses of the SFT-mooring line model based on Orca Flex to study the global dynamic responses of the SFT at the moment of cable breakage and the redistribution of cable internal forces.The most unfavorable position for SFT cable breakage was identified,the influence mechanism of cable breakage at different positions on the global dynamic response was revealed,and the progressive chain failure pattern caused by localized cable breakage are also clarified. 展开更多
关键词 submerged floating tunnel cable breakage global dynamic responses progressive failure
下载PDF
Analytical modeling and approaches of multihelix cables incorporating with interwire mutual contacts
15
作者 Zhichao ZHANG Xingzhe WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第9期1633-1654,共22页
This study aims to develop an analytical model based on the curve beam theory to capture the mechanical response of a multihelix cable considering the internal contact displacements.Accordingly,a double-helix cable su... This study aims to develop an analytical model based on the curve beam theory to capture the mechanical response of a multihelix cable considering the internal contact displacements.Accordingly,a double-helix cable subjected to axial tension and torsion is analyzed,and both the line and point contacts between the neighboring wires and strands are considered via an equivalent homogenized approach.Then,the proposed theoretical model is extended to a hierarchical multihelix cable with mutual contact displacements by constructing a recursive relationship between the high-and low-level multihelix structures.The global tensile stiffness and torsional stiffness of the double-helix cable are successfully evaluated.The results are validated by a finite element(FE)model,and are found to be consistent with the findings of previous studies.It is shown that the contact deformations in multihelix cables significantly affect their equivalent mechanical stiffness,and the contact displacements are remarkably enhanced as the helix angles increase.This study provides insights into the interwire/interstrand mutual contact effects on global and local responses. 展开更多
关键词 wordshierarchical multihelix cable mutual contact effect mechanical response effective stiffness
下载PDF
Pairing nitroxyl radical and phenazine with electron-withdrawing/-donating substituents in “water-in-ionic liquid” for high-voltage aqueous redox flow batteries
16
作者 Zhifeng Huang Rolf Hempelmann +2 位作者 Yiqiong Zhang Li Tao Ruiyong Chen 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第4期713-722,共10页
Aqueous redox-active organic materials-base electrolytes are sustainable alternatives to vanadium-based electrolyte for redoxflow batteries(RFBs)due to the advantages of high ionic conductivity,environmentally benign,s... Aqueous redox-active organic materials-base electrolytes are sustainable alternatives to vanadium-based electrolyte for redoxflow batteries(RFBs)due to the advantages of high ionic conductivity,environmentally benign,safety and low cost.However,the underexplored redox properties of organic materials and the narrow thermodynamic electrolysis window of water(1.23 V)hinder their wide applications.Therefore,seeking suitable organic redox couples and aqueous electrolytes with a high output voltage is highly suggested for advancing the aqueous organic RFBs.In this work,the functionalized phenazine and nitroxyl radical with electron-donating and electron-withdrawing group exhibit redox potential of-0.88 V and 0.78 V vs.Ag,respectively,in“water-in-ionic liquid”supporting electrolytes.Raman spectra reveal that the activity of water is largely suppressed in“water-in-ionic liquid”due to the enhanced hydrogen bond interactions between ionic liquid and water,enabling an electrochemical stability window above 3 V.“Water-in-ionic liquid”supporting electrolytes help to shift redox potential of nitroxyl radical and enable the redox activity of functionalized phenazine.The assembled aqueous RFB allows a theoretical cell voltage of 1.66 V and shows a practical discharge voltage of 1.5 V in the“water-in-ionic liquid”electrolytes.Meanwhile,capacity retention of 99.91%per cycle is achieved over 500 charge/discharge cycles.A power density of 112 mW cm^(-2) is obtained at a current density of 30 mA cm^(-2).This work highlights the importance of rationally combining supporting electrolytes and organic molecules to achieve high-voltage aqueous RFBs. 展开更多
关键词 Aqueous redoxflow batteries Water-in-ionic liquid electrolytes high-voltage aqueous batteries Organic redox-active materials
下载PDF
Case study on the mechanics of NPR anchor cable compensation for large deformation tunnel in soft rock in the Transverse Mountain area,China
17
作者 LI Yong ZHENG Jing +3 位作者 HUO Shu-sen WANG Feng-nian HE Man-chao TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2054-2069,共16页
A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri... A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas. 展开更多
关键词 soft rock large deformation NPR anchor cable physical model numerical simulation compensation mechanics
下载PDF
Exploring the feasibility of prestressed anchor cables as an alternative to temporary support in the excavation of super-large-span tunnel
18
作者 Shunhua Zhou Yuyin Jin +3 位作者 Zhiyao Tian Chunhua Zou Heming Zhao Zengrun Miao 《Railway Engineering Science》 EI 2024年第3期344-360,共17页
Excavating super-large-span tunnels in soft rock masses presents significant challenges.To ensure safety,the sequential excavation method is commonly adopted.It utilizes internal temporary supports to spatially partit... Excavating super-large-span tunnels in soft rock masses presents significant challenges.To ensure safety,the sequential excavation method is commonly adopted.It utilizes internal temporary supports to spatially partition the tunnel face and divide the excavation into multiple stages.However,these internal supports generally impose spatial constraints,limiting the use of large-scale excavation equipment and reducing construction efficiency.To address this constraint,this study adopts the“Shed-frame”principle to explore the feasibility of an innovative support system,which aims to replace internal supports with prestressed anchor cables and thus provide a more spacious working space with fewer internal obstructions.To evaluate its effectiveness,a field case involving the excavation of a 24-m span tunnel in soft rock is presented,and an analysis of extensive field data is conducted to study the deformation characteristics of the surrounding rock and the mechanical behavior of the support system.The results revealed that prestressed anchor cables integrated the initial support with the shed,creating an effective“shed-frame”system,which successively maintained tunnel deformation and frame stress levels within safe regulatory bounds.Moreover,the prestressed anchor cables bolstered the surrounding rock effectively and reduced the excavation-induced disturbance zone significantly.In summary,the proposed support system balances construction efficiency and safety.These field experiences may offer valuable insights into the popularization and further development of prestressed anchor cable support systems. 展开更多
关键词 Super-large-span tunnel Construction safety Sequential excavation method Shed-frame principle Prestressed anchor cables
下载PDF
Three-dimensional limit variation analysis on the ultimate pullout capacity of the anchor cables based on the Hoek-Brown failure criterion
19
作者 ZUO Shi ZHAO Lianheng HU Shihong 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1036-1047,共12页
Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC)of anchor cables in most previous research.This study focuses on a more comprehensive combinat... Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC)of anchor cables in most previous research.This study focuses on a more comprehensive combination failure mode that consists of bond failure of an anchorage body and failure of an anchored rock mass.The three-dimensional ultimate pullout capacity of the anchor cables is calculated based on the Hoek-Brown failure criterion and variation analysis method.The numerical solution for the curvilinear function in fracture plane is obtained based on the finite difference theory,which more accurately reflects the failure state of the anchor cable,as opposed to that being assumed in advance.The results reveal that relying solely on a single failure mode for UPC calculations has limitations,as changes in parameter values not only directly impact the UPC value but also can alter the failure model and thus the calculation method. 展开更多
关键词 Anchor cable Ultimate pullout capacity(UPC) Failure model Variation analysis Hoek-Brown failure criterion
下载PDF
Analyzing the Form-Finding of a Large-Span Transversely Stiffened Suspended Cable System: A Method Considering Construction Processes
20
作者 Junyu Chen Yanfei Wang +2 位作者 Ke Chen Shiqing Huang Xiaowen Xu 《World Journal of Engineering and Technology》 2024年第2期229-244,共16页
The precise control of the shape of transversely stiffened suspended cable systems is crucial. However, existing form-finding methods primarily rely on iterative calculations that treat loads as fixed known conditions... The precise control of the shape of transversely stiffened suspended cable systems is crucial. However, existing form-finding methods primarily rely on iterative calculations that treat loads as fixed known conditions. These methods are inefficient and fail to accurately control shape results. In this study, we propose a form-finding method that analyzes the load response of models under different sag and stress levels, taking into account the construction process. To analyze the system, a structural finite element model was established in ANSYS, and geometric nonlinear analysis was conducted using the Newton-Raphson method. The form-finding analysis results demonstrate that the proposed method achieves precise control of shape, with a maximum shape error ranging from 0.33% to 0.98%. Furthermore, the relationships between loads and tension forces are influenced by the deformed shape of the structures, exhibiting significant geometric nonlinear characteristics. Meanwhile, the load response analysis reveals that the stress level of the self-equilibrium state in the transversely stiffened suspended cable system is primarily governed by strength criteria, while shape is predominantly controlled by stiffness criteria. Importantly, by simulating the initial tensioning process as an initial condition, this method solves for a counterweight that satisfies the requirements and achieves a self-equilibrium state with the desired shape. The shape of the self-equilibrium state is precisely controlled by simulating the construction process. Overall, this work presents a new method for analyzing the form-finding process of large-span transversely stiffened suspended cable system, considering the construction process which was often overlooked in previous studies. 展开更多
关键词 cable Structure Long-Span Structure Form-Finding Analysis Finite Element Simulation Transverse cable Stiffening System
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部