检索结果-南通市图书馆

Buckling optimization of curvilinear fiber-reinforced composite structures using a parametric level set method

Frontiers of Mechanical Engineering 2024年第1期19卷 149-160页

作者： Ye TIAN Tielin SHI Qi XIA State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Owing to their excellent performance and large design space,curvilinear fiber-reinforced composite structures have gained considerable attention in engineering fields such as aerospace and automobile.In addition to the stiffness and strength of such structures,their stability also needs to be taken into account in the design.This study proposes a level-set-based optimization framework for maximizing the buckling load of curvilinear fiber-reinforced composite structures.In the proposed method,the contours of the level set function are used to represent fiber paths.For a composite laminate with a certain number of layers,one level set function is defined by radial basis functions and expansion coefficients for each layer.Furthermore,the fiber angle at an arbitrary point is the tangent orientation of the contour through this point.In the finite element of buckling,the stiffness and geometry matrices of an element are related to the fiber angle at the element centroid.This study considers the parallelism constraint for fiber paths.With the sensitivity calculation of the objective and constraint functions,the method of moving asymptotes is utilized to iteratively update all the expansion coefficients regarded as design variables.Two numerical examples under different boundary conditions are given to validate the proposed approach.Results show that the optimized curved fiber paths tend to be parallel and equidistant regardless of whether the composite laminates contain holes or not.Meanwhile,the buckling resistance of the final design is significantly improved.

关键词： buckling optimization curvilinear fiber composite structure level set method manufacturing constraint

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Displacement and force analyses of piles in the pile-caisson composite structure under eccentric inclined loading considering different stratum features

引用

Frontiers of Structural and Civil Engineering 2023年第10期17卷 1517-1534页

作者： Xiaoqing ZHAO Jinchang WANG Panpan GUO Xiaonan GONG Yongle DUAN Research Center of Coastal and Urban Geotechnical Engineering Zhejiang UniversityHangzhou 310058China Institute of Transportation Engineering Zhejiang UniversityHangzhou 310058China College of Civil Engineering Hefei University of TechnologyHefei 230009China China North Industries Norengeo Ltd. Shijiazhuang 050051China

A novel anchorage for long-span suspension bridges,called pile-caisson composite structures,was recently proposed by the authors in an attempt to reduce the construction period and costs.This study aims to investigate the displacement and force behavior of piles in a pile-caisson composite structure under eccentric inclined loading considering different stratum features.To this end,both 1g model tests and three-dimensional numerical simulations were performed.Two groups of 1g model tests were used to validate the finite-element(FE)method.Parametric studies were then performed to investigate the effects of groundwater level,burial depth of the pile-caisson composite structure,and distribution of soil layers on the performance of the pile-caisson composite structure.The numerical analyses indicated that the influence of the groundwater level on the stability of the caisson was much greater than that of the piles.In addition,increasing the burial depth of the pile-caisson composite structure can assist in reducing the displacements and improving the stability of the pile-caisson composite structure.In addition,the distribution of soil layers can significantly affect the stability of the pile-caisson composite structure,especially the soil layer around the caisson.

关键词： composite structure piles foundation suspension bridge 1g model test finite-element analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

INFLUENCE OF DAMPING MODELS ON DYNAMIC ANALYSES OF A BASE-ISOLATED composite structure UNDER EARTHQUAKES AND ENVIRONMENTAL VIBRATIONS

引用

工程力学 2022年第3期39卷 201-211页

作者：费一凡田源黄羽立陆新征 Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil EngineeringTsinghua UniversityBeijing 100084China

Structural design simultaneously governed by earthquakes and environmental vibrations has received a lot of attention in recent years.Base-isolated composite structures are typically used in the above-mentioned structural design.The corresponding analysis involves validating structural safety under earthquakes and human comfort under environmental vibrations through a time-history analysis.Thus,a reasonable damping model is essential.In this work,the representatives of viscous damping model and rate-independent damping model,namely the Rayleigh damping model and uniform damping model,were adopted to investigate the influence of damping models on the time-history analysis of such structural designs.The energy dissipation characteristics of the above-mentioned damping models were illustrated via a dynamic test of recycled aggregate concrete specimens.A case study was performed on a base-isolated steelconcrete composite structure.The dynamic responses under the excitation of earthquakes and environmental vibrations were compared using different damping models.The uniform damping model was found to be more flexible than the Rayleigh damping model in dealing with excitations with different frequency components.The uniform damping model is both theoretically advantageous and easy to use,demonstrating its potential in dynamic analysis of structures designed simultaneously governed by earthquakes and environmental vibrations.

关键词： seismic and environmental vibration analysis Rayleigh damping model uniform damping model seismic isolation composite structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Basic Physical Characteristics of the Water-permeable Brick with composite structure

引用

Journal of Wuhan University of Technology(Materials Science) 2022年第4期37卷 645-655页

作者：王海峰 LIU Yang MEI Zhen College of Civil Engineering Huaqiao UniversityXiamen 361021China Higher-educational Engineering Research Centre for Intelligence and Automation in Construction of Fujian Province College of Civil EngineeringHuaqiao UniversityXiamen 361021China

The resin-sand mixture was proposed to be used as the surface course,and cement permeable concrete was used as the base course;such two kinds of materials were combined to prepare water-permeable brick with a composite structure.The compressive strength,flexural strength,and permeability were studied by using adjusting the contents of carbon fiber,quartz powder,cement,sand,and surfactant.The study shows that the hydrophilicity of the resin-sand mixture can be improved after any amount of resin is replaced by quartz powder;by using the surfactant,the interface energy of the particles can be reduced so that the water permeability of the surface course can be promoted effectively.However,the mechanical properties of the surface course were negatively affected by the surfactant.With the optimal process consideration in the experiments,the properties about compressive strength,flexural strength,and permeability of the composite permeable brick can meet the requirements of the specifications of resin-sand based water permeable brick JGT 376-2012(compressive strength was higher than 35 MPa,the flexural strength exceeded 5.19 MPa,and the average permeability coefficient was higher than 2.3×10^(-2)cm/s).There are no obvious pores on the surface course and only water molecules can pass through it,therefore,the surface of the permeable brick cannot be blocked up by solid substances,and the permeability of such permeable brick can be improved effectively in this way.

关键词： water-permeable brick resin composite structure permeability surfactant

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Machine Learning Based Quantitative Damage Monitoring of composite structure

引用

International Journal of Smart and Nano Materials 2022年第2期13卷 167-202页

作者： Xinlin Qing Yunlai Liao Yihan Wang Binqiang Chen Fanghong Zhang Yishou Wang School of Aerospace Engineerin Xiamen UniversityXiamenFujian China National Center for Applied Mathematics Chongqing Normal UniversityChongqingSichuan China

composite materials have been widely used in many industries due to their excellent mechanical properties.It is difficult to analyze the integrity and durability of composite structures because of their own characteristics and the complexity of load and environments.Structural health monitoring(SHM)based on built-in sensor net-works has been widely evaluated as a method to improve the safety and reliability of composite structures and reduce the operational cost.With the rapid development of machine learning,a large number of machine learning algorithms have been applied in many disciplines,and also are being applied in the field of SHM to avoid the limitations resulting from the need of physical models.In this paper,the damage monitoring technologies often used for composite structures are briefly outlined,and the applications of machine learning in damage monitoring of composite structures are concisely reviewed.Then,challenges and solutions for quanti-tative damage monitoring of composite structures based on machine learning are discussed,focusing on the complete acquisi-tion of monitoring data,deep analysis of the correlation between sensor signal eigenvalues and composite structure states,and quantitative intelligent identification of composite delamination damage.Finally,the development trend of machine learningbased SHM for composite structures is discussed.

关键词： composite structure structural health monitoring machine learning built-in sensor network structural damage

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Preparation of Flower-like Copper Foam Supported Co_(3)O_(4) Electrocatalyst and Its Hydrogen Evolution Performance

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 327-331页

作者：李兆 CHENG Julong WANG Yanan WU Kunyao CAO Jing School of Materials Engineering Xi’an Aeronautical InstituteXian 710077China

Flower-like copper foam Co_(3)O_(4) catalysts(Co_(3)O_(4)/CF) were prepared by hydrothermal method.The crystalline structure and microscopic morphology of the prepared samples were characterized by using X-ray diffractometer(XRD) and scanning electron microscope(SEM),and the electrochemical properties were investigated by an electrochemical workstation.The experimental results show that the Co_(3)O_(4) catalysts are successfully prepared on the foamed copper support by hydrothermal method,and the material’s morphology is mainly flower cluster.When the current density is 10 mA·cm^(-2),the overpotential value of the Co_(3)O_(4)/CF catalyst is 141 mV,lower than that of blank support.The electrochemical impedance(EIS) spectrum shows that the R_(ct )value of the Co_(3)O_(4)/CF catalyst decreases,and the Coulomb curves of double-layer show that the electrochemically active area of the Co_(3)O_(4)/CF catalyst efficiently increases compared with that of the blank support.Therefore,the as-obtained Co_(3)O_(4)/CF catalyst exhibits a good hydrogen evolution rate,showing great applicability potential in the catalytic electrolysis of water for hydrogen production.

关键词： Co_(3)O_(4)/CF composite structure electrocatalysis hydrogen evolution reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Calculation Model for the Steady-State Vibration Amplitude of a New Type of Cascaded composite structure-Based Ultrasonic Transducer

引用

Nanomanufacturing and Metrology 2023年第3期6卷 91-99页

作者： Hongjie Zhang Xinyue Gao Xiaochen Liu Junqiang Wu Tianjin Key Laboratory of Modern Mechatronics Equipment Technology School of Mechanical EngineeringTiangong UniversityTianjin300387China

The steady-state vibration amplitude is an important performance indicator of high-frequency ultrasonic transducers for ultrasonically assisted manipulating,machining,and manufacturing.This work aimed to develop a calculation model for the steady-state vibration amplitude of a new type of dual-branch cascaded composite structure-based ultrasonic transducer that can be used in the packaging of microelectronic chips.First,the steady-state vibration amplitude of the piezoelectric vibrator of the transducer was derived from the piezoelectric equation.Second,the vibration transfer matrices of the tapered ultrasonic horns were obtained by combining the vibration equation,the continuous condition of the displacement,and the equilibrium condition of the force.Calculation models for the steady-state vibration amplitude of the two working ends of the transducer were then developed.A series of exciting trials were carried out to test the performance of the models.Comparison between the calculated and measured results for steady-state vibration amplitude showed that the maximum deviation was 0.0221μm,the minimum deviation was 0.0013μm,the average deviation was 0.0097μm,and the standard deviation was 0.0046μm.These values indicated good calculation accuracy,laying a good foundation for the practical application of the proposed transducer.

关键词： Piezoelectric ultrasonic transducer Thermosonic bonding Microelectronic packaging composite structure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

composite structure and properties of the pitcher surface of the carnivorous plant Nepenthes and its influence on the insect attachment system

引用

Progress in Natural Science:Materials International 2009年第12期19卷 1657-1664页

作者： Lixin Wang,Qiang Zhou~*,Yongjun Zheng,Shuyan Xu Department of Mechatronic Engineering,China Agricultural University,Beijing 100083,China Department of Mechatronic Engineering China Agricultural University Beijing 100083 China

Pitchers of the carnivorous plant Nepenthes have evolved specialized organs serving the purpose of attracting,capturing,retaining and digesting small animals,mostly insects.They consist of several well distinguishable zones,including a leaf-like lid,a collar-like peristome, a slippery zone and a digestive zone,differing in morphology,microstructure,chemical composition and physical properties.Discriminating zones display different functions,and the combined effects of several zones result in great trapping efficiency.The principal aim of this review is to introduce the structure and physiochemical properties of the pitcher surface,as well as the interaction between the pitcher surface and the insect attachment systems.Combining with our present study,the potential application of the pitcher surface being utilized in bionics to manufacture insect slippery trapping plates is discussed,and the original research direction of the pitcher surface and its application on agricultural pest control is highlighted.

关键词： Pitcher surface Nepenthes composite structure Insect Attachment system

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

composite wave-absorbing structure combining thin plasma and metasurface

引用

Plasma Science and Technology 2023年第4期25卷 148-155页

作者：郝志安李健飞徐彬姚静锋袁承勋王莹周忠祥王晓鸥 School of Physics Harbin Institute of TechnologyHarbin 150000People's Republic of China National Key Laboratory of Electromagnetic Environment(LEME) China Research Institute of Radio Wave PropagationQingdao 266107People's Republic of China Heilongjiang Provincial Key Laboratory of Plasma Physics and Technology Harbin 150000People's Republic of China

In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section(RCS)of the target,we designed a novel composite structure of a metasurface and plasma.A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber.The reflection and absorption of the composite structure are numerically and experimentally verified.The finite integration method was used to simulate a composite structure of finite size to obtain the RCS.The experimental measurements of electromagnetic wave reflection were conducted by a vector network analyzer(Keysight N5234A)and horn antennas,etc.The research showed that the absorption capacity of this composite structure was substantially improved compared to either the plasma or the metasurface,and it is more convenient for application due to its low plasma thickness requirement and easy fabrication.

关键词： plasma metasurface composite structure radar scattering cross section

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

BOUNDARY ELEMENT METHOD FOR MODEL ANALYSIS OF 2-D composite structure

引用

Acta Mechanica Solida Sinica 1998年第1期11卷 63-71页

作者： Zou Jing Li Zailiang Zhong Weifang Huazhong Univ Sci & Technol Dept Mech Wuhan 430074 Peoples R China

The boundary element method is used for he modal analysis of freevibration of 2-D composite structures in this paper. Since theparticular solution method is used to treat the terms of body forces(inertial forces) in the equation of motion, only static fundamentalsolutions are needed in solving the problem. For an isotropiccantilever beam, the numerical results obtained by using the BEMpresented in this paper are in good agreement, with those of usingFEM or other BEM, but this BEM can also be used to analyze problemsfor anisotropic materials.

关键词： composite structure boundary element method particular solution method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：