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Anisotropy of multi-layered structure with sliding and bonded interlayer conditions

Lingyun YOU, Kezhen YAN, Jianhong MAN, Nengyuan LIU

《结构与土木工程前沿(英文)》 2020年 第14卷 第3期   页码 632-645 doi: 10.1007/s11709-020-0617-4

摘要: A better understanding of the mechanical behavior of the multi-layered structure under external loading is the most important item for the structural design and the risk assessment. The objective of this study are to propose and develop an analytical solution for the mechanical behaviors of multi-layered structure generated by axisymmetric loading, and to investigate the impact of anisotropic layers and interlayer conditions on the multi-layered structure. To reach these objectives, first, according to the governing equations, the analytical solution for a single layer was formulated by adopting the spatial Hankel transform. Then the global matrix technique is applied to achieve the analytical solution of multi-layered structure in Hankel domain. The sliding and bonded interlayer conditions were considered in this process. Finally, the numerical inversion of integral transform was used to solve the components of displacement and stress in real domain. Gauss-Legendre quadrature is a key scheme in the numerical inversion process. Moreover, following by the verification of the proposed analytical solution, one typical three-layered flexible pavement was applied as the computing carrier of numerical analysis for the multi-layered structure. The results have shown that the anisotropic layers and the interlayer conditions significantly affect the mechanical behaviors of the proposed structure.

关键词: multi-layered structure     Hankel transformation     anisotropic     transversely isotropic     interlayer condition     Gauss-Legendre quadrature    

Design of nanofibre interlayer supported forward osmosis composite membranes and its evaluation in fouling

《环境科学与工程前沿(英文)》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1550-7

摘要:

• A fine fibre (40–60 nm diameter) interlayer (~1 µm thickness) was electrospun.

关键词: Forward osmosis     Electro-spinning     Interfacial polymerisation     Fouling     Polyvinylidene fluoride    

Assessing artificial neural network performance for predicting interlayer conditions and layer modulus

Lingyun YOU, Kezhen YAN, Nengyuan LIU

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 487-500 doi: 10.1007/s11709-020-0609-4

摘要: The objective of this study is to evaluate the performance of the artificial neural network (ANN) approach for predicting interlayer conditions and layer modulus of a multi-layered flexible pavement structure. To achieve this goal, two ANN based back-calculation models were proposed to predict the interlayer conditions and layer modulus of the pavement structure. The corresponding database built with ANSYS based finite element method computations for four types of a structure subjected to falling weight deflectometer load. In addition, two proposed ANN models were verified by comparing the results of ANN models with the results of PADAL and double multiple regression models. The measured pavement deflection basin data was used for the verifications. The comparing results concluded that there are no significant differences between the results estimated by ANN and double multiple regression models. PADAL modeling results were not accurate due to the inability to reflect the real pavement structure because pavement structure was not completely continuous. The prediction and verification results concluded that the proposed back-calculation model developed with ANN could be used to accurately predict layer modulus and interlayer conditions. In addition, the back-calculation model avoided the back-calculation errors by considering the interlayer condition, which was barely considered by former models reported in the published studies.

关键词: asphalt pavement     interlayer conditions     finite element method     artificial neural network     back-calculation    

Block copolymers as efficient cathode interlayer materials for organic solar cells

Dingqin Hu, Jiehao Fu, Shanshan Chen, Jun Li, Qianguang Yang, Jie Gao, Hua Tang, Zhipeng Kan, Tainan Duan, Shirong Lu, Kuan Sun, Zeyun Xiao

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 571-578 doi: 10.1007/s11705-020-2010-1

摘要: Emerging needs for the large-scale industrialization of organic solar cells require high performance cathode interlayers to facilitate the charge extraction from organic semiconductors. In addition to improving the efficiency, stability and processability issues are major challenges. Herein, we design block copolymers with well controlled chemical composition and molecular weight for cathode interlayer applications. The block copolymer coated cathodes display high optical transmittance and low work function. Conductivity studies reveal that the block copolymer thin film has abundant conductive channels and excellent longitudinal electron conductivity due to the interpenetrating networks formed by the polymer blocks. Applications of the cathode interlayers in organic solar cells provide higher power conversion efficiency and better stability compared to the most widely-applied ZnO counterparts. Furthermore, no post-treatment is needed which enables excellent processability of the block copolymer based cathode interlayer.

关键词: organic solar cell     block copolymer     cathode interlayer    

A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

《工程管理前沿(英文)》 2020年 第7卷 第3期   页码 323-334 doi: 10.1007/s42524-020-0121-5

摘要: Condition-based maintenance (CBM) detects early signs of failure and dictates when maintenance should be performed based on the actual condition of a system. In this paper, we first review some of the recent research on CBM under various physical structures and signal data. Then, we summarize several kinds of prognostic models that use monitoring information to estimate the reliability of complex systems or products. Monitoring information also facilitates operational decisions in production planning, spare parts management, reliability improvement, and prognostics and health management. Finally, we suggest some research opportunities for the reliability and operations management communities to fill the research gap between these two fields.

关键词: condition-based maintenance     prognostics     operational decision-making     reliability    

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要: Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词: water injection units     condition-based maintenance     trend prediction    

爆破飞石受软弱夹层影响分析及其在复杂环境下的控制

陈斌,和铁柱,赵明生

《中国工程科学》 2014年 第16卷 第11期   页码 53-57

摘要:

分析了在软弱夹层地质条件下爆破飞石产生的原因及机理,根据软弱夹层产生爆破飞石的特点,区分了在软弱夹层和一般岩体条件下飞石产生的差别。在软弱夹层的地质条件下以及城镇复杂的爆破环境下,给出了合理有效控制爆破飞石的措施。

关键词: 爆破飞石     软弱夹层     冲炮    

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

《机械工程前沿(英文)》 doi: 10.1007/s11465-021-0661-3

摘要: Tool failures in machining processes often cause severe damages of workpieces and lead to large quantities of loss, making tool condition monitoring an important, urgent issue. However, problems such as practicability still remain in actual machining. Here, a real-time tool condition monitoring method integrated in an in situ fiber optic temperature measuring apparatus is proposed. A thermal simulation is conducted to investigate how the fluctuating cutting heats affect the measuring temperatures, and an intermittent cutting experiment is carried out, verifying that the apparatus can capture the rapid but slight temperature undulations. Fourier transform is carried out. The spectrum features are then selected and input into the artificial neural network for classification, and a caution is given if the tool is worn. A learning rate adaption algorithm is introduced, greatly reducing the dependence on initial parameters, making training convenient and flexible. The accuracy stays 90% and higher in variable argument processes. Furthermore, an application program with a graphical user interface is constructed to present real-time results, confirming the practicality.

关键词: tool condition monitoring     cutting temperature     neural network     learning rate adaption    

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 345-356 doi: 10.1007/s11783-013-0574-4

摘要: Benzene removal from aqueous solutions was evaluated using Fe O nano magnetic particles (NM) in continuous condition. A 4 factorial design including initial benzene concentration, NM dose, contact time and pH was investigated in 16 experiments (Taguchi OA design). The results indicated that all factors were significant and the optimum condition was: pH 8, NM dose of 2000 mg·L , benzene concentrations of 100 mg·L and contact time of 14 min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4 mg·g and 38.4 L·g , respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Brunauer-Emmett-Teller model fit more closely and produced an isotherm constant (b) less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.

关键词: benzene     experimental design     Fe3O4     continues condition     thermal recycling    

Continuous amino-functionalized University of Oslo 66 membranes as efficacious polysulfide barriers for lithium−sulfur batteries

《化学科学与工程前沿(英文)》 2023年 第17卷 第2期   页码 194-205 doi: 10.1007/s11705-022-2206-7

摘要: The shuttle effect of soluble polysulfides is a serious problem impeding the development of lithium−sulfur batteries. Herein, continuous amino-functionalized University of Oslo 66 membranes supported on carbon nanotube films are proposed as ion-permselective interlayers that overcome these issues and show outstanding suppression of the polysulfide shuttle effect. The proposed membrane material has appropriately sized pores, and can act as ionic sieves and serve as barriers to polysulfides transport while allowing the passage of lithium ions during electrochemical cycles, thereby validly preventing the shuttling of polysulfides. Moreover, a fast catalytic conversion of polysulfides is also achieved with the as-developed interlayer. Therefore, lithium−sulfur batteries with this interlayer show a desirable initial capacity of 999.21 mAh·g–1 at 1 C and a durable cyclic stability with a decay rate of only 0.04% per cycle over 300 cycles. Moreover, a high area capacity of 4.82 mAh·cm–2 is also obtained even under increased sulfur loading (5.12 mg·cm–2) and a lean-electrolyte condition (E/S = 4.8 μL·mg–1).

关键词: lithium−sulfur batteries     amino-functionalized University of Oslo 66 membrane     polysulfide     interlayer    

Earthquake analysis of arch and gravity dams including the effects of foundation inhomogeneity

LIN Gao, DU Jianguo, HU Zhiqiang

《结构与土木工程前沿(英文)》 2007年 第1卷 第1期   页码 41-50 doi: 10.1007/s11709-007-0004-4

摘要: Dam-foundation interaction plays an important role in the design of earthquake-resistant concrete arch and gravity dams. Geological conditions of the dam canyon are usually very complicated; however, in the literature, the damfoundation interaction analysis is often carried out based on the premise of a homogeneous unbounded foundation. In this paper, the effect of foundation inhomogeneity on the seismic response of arch and gravity dams was studied by means of scaled boundary finite element method (SBFEM). In order to satisfy the similarity requirement of SBFEM and simplify the computational effort, a subdomain approach and a conical representation of an unbounded foundation were proposed. The way of partitioning the domain and the selection of open angle and bottom radius of the cone model on the accuracy of the result were examined. Numerical examples show that the proposed approach is rational and efficient. Cases of foundation inhomogeneity with stiffness varying in accordance with an exponential function along the radial direction, and cases of foundation inhomogeneity with stiffness discontinuity and with weak interlayer strata on the earthquake response of concrete arch dams as well as gravity dams were analyzed. It was found that a homogeneous idealization of the unbounded foundation may sometimes greatly underestimate the maximum earthquake stress response of the dam. Therefore, taking into account the effect of foundation inhomogeneity for the earthquake safety assessment of concrete arch and gravity dams has great significance.

关键词: selection     interlayer     damfoundation interaction     Geological     computational    

In-situ condition monitoring of reinforced concrete structures

Sanjeev Kumar VERMA,Sudhir Singh BHADAURIA,Saleem AKHTAR

《结构与土木工程前沿(英文)》 2016年 第10卷 第4期   页码 420-437 doi: 10.1007/s11709-016-0336-z

摘要: Performance of concrete structures is significantly influenced and governed by its durability and resistance to environmental or exposure conditions, apart from its physical strength. It can be monitored, evaluated and predicted through modeling of physical deterioration mechanisms, performance characteristics and parameters and condition monitoring of in situ concrete structures. One such study has been conducted using Non-destructive testing equipment in the city of Bhopal and around located in India. Some selected parameters influencing durability of reinforced concrete (RC) structures such as concrete cover, carbonation depth, chloride concentration, half cell potential and compressive strength have been measured, for establishing correlation among various parameters and age of structures. Effects of concrete cover and compressive strength over the variation of chloride content with time are also investigated.

关键词: concrete     carbonation     chloride     corrosion     monitoring     models    

Distributed flexible reconfigurable condition monitoring and diagnosis technology

HU You-min, YANG Shu-zi, DU Run-sheng

《机械工程前沿(英文)》 2006年 第1卷 第3期   页码 276-281 doi: 10.1007/s11465-006-0025-z

摘要: As manufacturing becomes increasingly decentralized, flexible and reconfigurable, more research needs to be done on monitoring and diagnosis technology that accommodate these new trends. The distributed condition monitoring and diagnosis technology based on the flexible and reconfigurable concept is studied here. A condition monitoring diagnosis model based on the distributed flexible and reconfigurable idea is proposed in this paper. The component makeup and functions of this model are discussed in detail. The model can fulfill in most instances the manufacturing system requirements for changing the configuration of the monitoring diagnosis system according to different manufacturing system configurations. This model also realizes the flexibility and reconfigurability of the monitoring diagnosis system in some degree. The model has already spawned a successful prototype for monitoring a chemical plant in accomplishing monitoring and control of the production process and equipment. Finally, some future research work is pointed out.

关键词: chemical     diagnosis system     configuration     monitoring     equipment    

Comprehensive health condition assessment on partial sewers in a southern Chinese city based on fuzzy

Lili GAN, Jiane ZUO, Yajiao WANG, Thong Soon LOW, Kaijun WANG

《环境科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 144-150 doi: 10.1007/s11783-013-0554-8

摘要: A self-developed sewer health assessment system using the fuzzy comprehensive evaluation and analytical hierarchy process was applied to give a comprehensive health condition evaluation on part of the local sewers in a southern Chinese city based on the sewer video data collected by a sewer inspection closed circuit television (CCTV) robot. Aside from the overall condition evaluation, the structure, function, and stability status of the sewer were also analyzed using the method. A comprehensive index was proposed to give the overall health condition of pipes with different defects, and , , and were used to quantify the defects affecting the tightness, stability, and function of the pipe, respectively. Results show that 48% of the inspected pipes were in good condition (0< <0.25), and about 33% of the sewer pipes analyzed were categorized to be at severe or urgent condition levels ( >0.5), although most of the pipes were installed only within five years. Frequent sedimentation affects the function of the sewer, and deformation and joint damage affect the structure of the sewer.

关键词: sewer     health condition assessment     analytical hierarchy process     fuzzy comprehensive evaluation     fuzzy mathematic method    

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 90-95 doi: 10.1007/s11465-005-0006-7

摘要:

To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.

关键词: preferable     inexistence     Results     validity     boundary condition    

标题 作者 时间 类型 操作

Anisotropy of multi-layered structure with sliding and bonded interlayer conditions

Lingyun YOU, Kezhen YAN, Jianhong MAN, Nengyuan LIU

期刊论文

Design of nanofibre interlayer supported forward osmosis composite membranes and its evaluation in fouling

期刊论文

Assessing artificial neural network performance for predicting interlayer conditions and layer modulus

Lingyun YOU, Kezhen YAN, Nengyuan LIU

期刊论文

Block copolymers as efficient cathode interlayer materials for organic solar cells

Dingqin Hu, Jiehao Fu, Shanshan Chen, Jun Li, Qianguang Yang, Jie Gao, Hua Tang, Zhipeng Kan, Tainan Duan, Shirong Lu, Kuan Sun, Zeyun Xiao

期刊论文

A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

爆破飞石受软弱夹层影响分析及其在复杂环境下的控制

陈斌,和铁柱,赵明生

期刊论文

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

期刊论文

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

期刊论文

Continuous amino-functionalized University of Oslo 66 membranes as efficacious polysulfide barriers for lithium−sulfur batteries

期刊论文

Earthquake analysis of arch and gravity dams including the effects of foundation inhomogeneity

LIN Gao, DU Jianguo, HU Zhiqiang

期刊论文

In-situ condition monitoring of reinforced concrete structures

Sanjeev Kumar VERMA,Sudhir Singh BHADAURIA,Saleem AKHTAR

期刊论文

Distributed flexible reconfigurable condition monitoring and diagnosis technology

HU You-min, YANG Shu-zi, DU Run-sheng

期刊论文

Comprehensive health condition assessment on partial sewers in a southern Chinese city based on fuzzy

Lili GAN, Jiane ZUO, Yajiao WANG, Thong Soon LOW, Kaijun WANG

期刊论文

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

期刊论文