检索结果-南通市图书馆

IEc/cISPR/D 国际标准工作组会议在新加坡召开

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

安全与电磁兼容 2024年第2期 99-99页

IEc/cISPR/D国际标准工作组会议于2024年2月26-28日在新加坡举办。IEc/cISPR/D是负责汽车电磁兼容发射类基础标准的国际标准组织,其制订的多项标准已成为国际法规、国内强制性标准的依据。此次会议的与会国际专家对cISPR 12/cISPR 25两... 详细信息

IEc/cISPR/D国际标准工作组会议于2024年2月26-28日在新加坡举办。IEc/cISPR/D是负责汽车电磁兼容发射类基础标准的国际标准组织,其制订的多项标准已成为国际法规、国内强制性标准的依据。此次会议的与会国际专家对cISPR 12/cISPR 25两项标准的技术内容进行了现场讨论并获得积极成果。

关键词：国际标准组织 cISPR 工作组会议 c/c ISP 现场讨论强制性标准汽车电磁兼容

在线全文

学校读者我要写书评

暂无评论

c／c复合材料

科技开发动态 2004年第6期 32-32页

作者：魏向东 110015沈阳市文化路72号中国科学院金属研究所

Influence of Fabric Parameters on Microstructure,Mechanical Properties and Failure Mechanisms in carbon-Fibre Reinforced composites

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

Journal of Materials Science & Technology 2008年第6期24卷 953-959页

作者： B.Wielage D.Richter H.Mucha Th.Lampke chemnitz University of Technology Institute of Composite Materials and Surface TechnologyD-09107 ChemnitzGermany

The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites （plastic and carbon matrix） have been investigated. The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy （SEM）, respectively whereas the mechanical behaviour was examined by 3- point bending experiments. Exclusively one type of experimental resole type phenolic resin was applied. A strong fibre/matrix bonding, which is needed for high strength of carbon fibre reinforced plastic （cFRP） materials leads to severe composite damages during the pyrolysis resulting in low strength, brittle failure and a very low utilisation of the fibres strain to failure in c/c composites. Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the cFRP＇s microstructure. Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged. Toughness is almost not affected. In c/c composites inhomogenities due to a reduced bundle size reduce strain to failure, strength, stiffness and toughness. Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour. Increasing the fabric density （weight per unit area） causes similar effects as in cFRPs.

关键词： cFRPs c/c Fibre/matrix bonding Fabric density Fibre volume fraction Roving size Microstructure Failure behaviour

碳/碳生物活性玻璃涂层复合材料的组织结构研究

在线全文

学校读者我要写书评

暂无评论

西北工业大学学报 2002年第4期20卷 612-615页

作者：熊信柏李贺军李克智西北工业大学c/c复合材料工程技术中心陕西西安710072

通过包埋 -粉末涂刷高温烧结工艺 ,以碳化硅作为过渡层制备出 c/c生物活性玻璃涂层复合材料。采用 SEM、EDS、XRD考察了涂层的组织结构 ,结果表明所制涂层具有多孔结构 ,从基体到生物活性玻璃涂层 ,成分和结构呈连续变化 ,消除了生物玻... 详细信息

通过包埋 -粉末涂刷高温烧结工艺 ,以碳化硅作为过渡层制备出 c/c生物活性玻璃涂层复合材料。采用 SEM、EDS、XRD考察了涂层的组织结构 ,结果表明所制涂层具有多孔结构 ,从基体到生物活性玻璃涂层 ,成分和结构呈连续变化 ,消除了生物玻璃与基体的性质差异 ,实现了在 c/c复合材料表面进行生物活性改性。

关键词：碳/碳生物活性玻璃涂层复合材料 c/c 碳化硅组织结构

在线全文

学校读者我要写书评

暂无评论

单壁碳纳米管屈曲的原子/连续介质混合模型

力学学报 2004年第6期36卷 744-748页

作者：张田忠上海大学上海市应用数学和力学研究所上海200072

提供了一种运用原子/连续介质混合(hybrid atomic/continuum,HAc)方法解决纳米力学问题的思路.通过在连续介质力学模型中引入利用分子力学方法获得物性参数,建立了预测单壁碳纳米管临界屈曲参数的HAc模型.结果表明,HAc模型具有与连续介... 详细信息

提供了一种运用原子/连续介质混合(hybrid atomic/continuum,HAc)方法解决纳米力学问题的思路.通过在连续介质力学模型中引入利用分子力学方法获得物性参数,建立了预测单壁碳纳米管临界屈曲参数的HAc模型.结果表明,HAc模型具有与连续介质力学模型可比拟的简洁性,同时可表征纳米管微观结构特征对屈曲参数的影响.计算结果表明,Zigzag纳米管的抗屈曲性能优于Armchair纳米管.基于Tersoff-Brenner作用势的分子动力学结果证实了这一结论.

关键词：连续介质力学原子屈曲 HAc 单壁碳纳米管临界分子力学纳米力学 c/c 分子动力学

Morphologies evolution and mechanical behaviors of Sic nanowires reinforced c/(Pyc-Sic)_(n)multilayered matrix composites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第1期96卷 190-198页

作者： Xinfa Tian Hejun Li Xiaohong Shi Hongjiao Lin Ningning Yan Tao Feng State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi’an 710072China School of Mechanics Civil Engineering&ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China

Sic nanowires reinforced c/(Pyc-Sic)_(n)multilayered matrix composites(SM-cS for short)were prepared by combined with sol-gel and chemical vapor infiltration(cVI)***,(Pyc-Si Oc);multilayered structure was formed by cycles of impregnation and *** SiOc was transformed into Sic by heat-treatment,and(Pyc-Sic)_(n)multilayered structure would be *** the same time,the Pyc layer which was designed as the outmost layer could decrease gas supersaturation to form in-situ tubular Sic nanowires on the surface of multilayered *** results of three-point bending test showed that the maximum force of SM-cS composites was increased by the number of cycles of the preparation process,which were up to enhanced by 74.38%compared with c/c composite *** fracture surface showed that the improvement was due to the multiscale reinforcing system of(Pyc-Sic)_(n)multilayered structure and Sic *** structure can protect carbon fibers and release stress concentration by induction of *** the mechanical interlocking effect of Sic nanowires could reinforce bonding force of the remaining matrix.

关键词： c/c Multilayered structure Sic nanowires Flexural property

Multi-physical field coupling simulation of TcVI process for preparing carbon/carbon composites

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2009年第11期52卷 3173-3179页

作者： JIAO YanQiong LI HeJun LI KeZhi Research center of carbon/carbon composites Laboratory of Thermostructure Composite MaterialsNorthwestern Polytechnical UniversityXi’an 710072China

To prepare carbon/carbon (c/c) composites with advanced performance, the thermal gradient chemical vapor infiltration (TcVI) process has been optimized by simulation. A 2D axisymmetric unstable model was built, which included convection, conduction, diffusion, densification reactions in the pores and the evolution of the porous medium. The multi-physical field coupling model was solved by finite element method (FEM) and iterative calculation. The time evolution of the fluid, temperature and preform density field were obtained by the calculation. It is indicated that convection strongly affects the temperature field. For the preform of carbon/carbon composites infiltrated for 100 h by TcVI, the radial average densities from simulation agrees well with those from experiment. The model is validated to be reliable and the simulation has capability of forecasting the process.

关键词： c/c composites TcVI multi-physical field coupling simulation

Densification and microstructure of carbon/carbon composites prepared by chemical vapor infiltration using ethanol as precursor

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第8期53卷 2232-2238页

作者： LI Wei,ZHANG ShouYang ,YAN XiaFeng,LI HeJun&LI KeZhi State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,china State Key Laboratory of Solidification Processing Northwestern Polytechnical University

chemical vapor infiltration of carbon fiber felts with uniform initial bulk density of 0.47 g·cm-3 was investigated at the ethanol partial pressures of 5-20 kPa,as well as the temperatures of 1050,1100,1150 and 1200°***,diluted by nitrogen,was employed as the precursor of pyrolytic *** light microscopy(PLM),scanning electron microscopy and X-ray diffraction were adopted to study the texture of pyrolytic carbon deposited at various temperatures.A change from medium-to high-textured pyrolytic carbon was observed in the sample infiltrated at 1050°***,homogeneous high-textured pyrolytic carbons were deposited at the temperatures of 1100,1150 and 1200°*** angles of 19°-21° were determined for different regions in the samples densified at the temperatures ranging from 1100 to 1200°*** electron microscopy of the fracture surface after bending test indicated that the prepared carbon/carbon composite samples exhibited a pseudo-plastic fracture *** addition,fracture behavior of the carbon/carbon samples was obviously effected by their infiltration *** fracture mode of c/c composites was transformed from shearing failure to tensile breakage with increasing infiltration temperature. Results of this study show that ethanol is a promising carbon source to synthesize carbon/carbon composites with homogeneously high-textured pyrolytic carbon over a wide range of temperatures(from 1100 to 1200°c).

关键词： c/c composites ethanol IcVI high-textured pyrolytic carbon

Modeling of cVI process in fabrication of carbon/carbon composites by an artificial neural network

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2003年第2期46卷 173-181页

作者：李爱军李贺军李克智顾正彬 Superhigh Temperature composites Key Laboratory Northwestern Polytechnical University

The chemical vapor infiltration(cVI) process in fabrication of carbon-carbon composites is very complex and highly inefficient, which adds considerably to the cost of fabrication and limits the application of the material. This paper tries to use a supervised artificial neural network(ANN) to model the nonlinear relationship between parameters of isothermal cVI(IcVI) processes and physical properties of c/c composites. A model for preprocessing dataset and selecting its topology is developed using the Levenberg-Marquardt training algorithm and trained with comprehensive dataset of tubal c/c components collected from experimental data and abundant simulated data obtained by the finite element method. A basic repository on the domain knowledge of cVI processes is established via sufficient data mining by the network. With the help of the repository stored in the trained network, not only the time-dependent effects of parameters in cVI processes but also their coupling effects can be analyzed and predicted. The results show that the ANN system is effective and successful for optimizing cVI processes in fabrication of c/c composites.

关键词： c/c composites, IcVI process, artificial neural network, Levenberg-Marquard algorithm, finite element method.