TECHNIQUES FOR CURE MONITORING OF THERMOSET RESINS AND COMPOSITES - A REVIEW

The efforts to ensure the manufacturing reliability and reproducibility of composite parts must start with the implementation of proper quality assurance and well-established processing procedures. These procedures are required to determine the curing kinetics, thermal stability, and optimum cure cycles of a matrix resin. The next key step is then to precisely control the curing process. A sensor to monitor the cure state in real-time during composite curing is important to the future automation of composite manufacturing. The present report begins by briefly reviewing the techniques for quality assurance and processability assessment. Also concisely presented are the concepts of cure environment modeling and expert systems, which are followed by a discussion on the various methods that are more feasible for in-process cure monitoring and management. This report also summarizes our efforts in cure sensor research and concludes by pointing out future research directions in cure control during composite manufacturing.     

激光加热下铜的再结晶织构及其机制探讨

冷变形金属再结晶织构受加热速度的影响很大。利用激光超快速加热方法对冷轧纯铜进行再结晶处理，其织构转变动力学过程与普通加热时不同，并受冷轧量的影响。     

被动电磁装甲对铜射流破坏作用仿真与实验研究

为了实现被动电磁装甲对射流的防护作用,分别对轴向脉冲电流对射流的颈缩、扭曲作用及装甲板对射流产生的横向电磁力作用机理进行了理论分析,考虑脉冲电流趋肤效应和射流为率相关弹塑性模型的前提下,利用ANSYS对这三种作用机理进行了电磁结构耦合仿真,分别得到了电流密度、磁感应强度、电磁力在射流上的分布规律以及射流的最终变形。最后针对三种作用机理分别进行了实验,实验结果证实了被动电磁装甲能够对射流产生破坏作用,在静破甲试验中,当充电电压为5 kV左右,峰值电流为150 kA时,直径为39.2 mm的破甲弹产生的射流侵彻深度降低了8.6%。     

复合材料迭层板壳有限单元法现状分析

本文从剖析单元构成因素的角度出发,综合评述了目前用于复合材料板壳结构分析的各种有限单元,分析了这些单元的特点及其适用范围,并说明Mindlin类等参板壳单元广泛应用迭层板壳的原因以及存在问题、解决办法。还深入地讨论了杂交单元应用至迭层板壳计算的优点。     

A REVIEW OF PLANT DESIGN TECHNIQUES

The development of techniques of plant layout and facilities design is followed, the various techniques reviewed, some questions of criteria, methodology and validity of the various approaches are discussed, and a number of suggestions and problems amenable to future investigation are presented.     

复杂环境下扩堑爆破及安全防护技术

在铁路复线建设和既有线改造中,如何保证既有线的运行和施工安全,是要特别注意的问题。基于铁路梅花山站高边坡扩堑爆破工程,分析了施工中可能出现的事故,制定了合理的爆破方案,采用同排同段孔外等间隔延时起爆网路和有效的安全防护措施,改善了岩石的破碎度,减少了二次破碎工作量,提高了施工进度,在复杂条件下实现了铁路运行和扩堑作业两不误。     

风荷载测试与模拟技术的回顾及展望

对大跨度桥梁、大跨空间结构、高层建筑、高耸塔桅结构等建筑物和构筑物而言，风荷载是结构抗风设计、防灾减灾分析的控制荷载之一。风与上述结构间的相互作用十分复杂，可通过风洞试验、现场实测、数值模拟等方法获取详细可靠的风荷载数据。本文简要介绍了大气边界层风特性与风荷载作用特点，回顾了结构风工程中风洞试验与现场实测的基本情况，讨论了风荷载时程的各种数值模拟技术，展望了风荷载测试与模拟技术研究的趋向。     

LASER MACHINING OF CERAMICS: A REVIEW

Laser machining techniques for ceramics are reviewed. The effect of laser characteristics on ceramics is examined and suggestions are given on the direction of future research.     

MACHINING PARAMETERS AND CUT QUALITY IN LASER CUTTING OF ARAMID FIBRE REINFORCED PLASTICS

This paper deals with the quality evaluation in laser cutting of Aramid Fibre Reinforced Plastics. The typical features of cuts are described and the influence of the process parameters on cutting result is discussed. A new methodology based on a digital image processing technique for the evaluation of cut quality is presented.     

定点激光反射热循环测量铜膜应力及屈服强度

采用定点激光反射热循环测量基片上薄膜应力的新方法，测定了硅片（１００）上四种厚度（０．２４μｍ，０．５３μｍ，１．２８μｍ，３．４２μｍ）磁控溅射纯铜膜应力随温度（２０～３００℃的变化，发现屈服强度与膜厚倒数成线性关系。     

焊接熔敷金属中扩散氢的色谱法试验研究

阐述了色谱法测定焊接熔敷金属中扩散氢的测试原理及基本操作程序。通过与国外同类仪器测试结果的比较分析，得出，国产SQK－1型焊缝金属扩散氢测试仪完全能满足测试精度要求，其优点是测试精度高、时间短、操作简便。     

圆筒形容器焊接错位产生的应力与变形

本文分析由于焊接工艺不善,产生的初应力和变形。其讨论三种常见的焊接错边问题。轴向焊接错位;径向焊接错位;以及圆筒搭边对焊后产生的初应力和变形。     

THE BEHAVIOUR OF FATIGUE CRACKS SUBJECT TO APPLIED BIAXIAL STRESS: A REVIEW OF EXPERIMENTAL EVIDENCE

Abstract— Experimental studies aimed at understanding the fatigue process in metals and polymers have usually been performed under uniaxial stress. Only in the last two decades or so has much experimentation been carried out on fatigue crack propagation under biaxial stress. This paper reviews the available published data. Crack propagation behaviour under biaxial stress is dictated by 3 parameters: stress biaxiality itself, which is defined here as the ratio of the in-plane principal stresses, crack angle with respect to the applied principal stress directions and stress intensity factor range. Depending on the first two parameters, cracks may grow in Mode I, Mode II or Mixed-Mode. Crack growth data have been presented using these three divisions. Two short sections have been included on initiation and cyclic stress/strain behaviour under biaxial stress to emphasise the fact that crack growth cannot be fully understood without knowing something of them. The accumulated data do not lead to adequate conclusions on either the qualitative or quantitative behaviour of cracks subject to cyclic in-plane biaxial stress. Reasons for the confusion and even contradiction of independent results are put forward and some discussion given to the possible directions of future experimental work.     

高性能热塑性树脂基复合材料复合方法及成型工艺简介

芳香族聚合物一类新型热塑性工程塑料的出现,有可能代替某些热固性树脂基体制作长纤维增强复合材料。国外对热塑性工程塑料树脂基复合材料进行了大量的研究,已经成功地应用于航空航天事业。保证这种材料取代某些热固性树脂基复合材料的前提是预浸带制造方法和成型工艺技术的实施。本文将对热塑性树脂基复合材料的预浸带制备及成型方法作一简单分析介绍。      

实验室间比对的能力验证及稳健统计技术第一讲能力验证的基本概念及活动的组织和设计

介绍了能力验证的基本概念。就能力验证的定义、分类、组织和设计、运作及能力评价等问题进行了讨论。介绍了与之相关的稳健统计技术及应用实例。     

A CRITICAL REVIEW OF LASER ABLATION-SYNTHESIS OF HIGH TEMPERATURE SUPERCONDUCTING FILMS

Laser ablation-deposition has become one of the most widely used techniques for synthesizing high temperature superconducting thin films. Therefore, it is important to understand the basic phenomena involved in laser-solid target interaction, and ablation, transport, and deposition of material onto appropriate substrates. Basic phenomena related to these processes are discussed in view of recent experimental and theoretical work performed by several groups, with the ultimate goal of optimizing this deposition technique and scaling up for application in technologies such as microelectronics     

WNQ570桥梁钢及其对接焊缝疲劳裂纹扩展性能试验研究

对WNQ570桥梁钢及其对接焊缝进行了疲劳裂纹扩展速率和疲劳裂纹扩展门槛值测定试验,采用两种不同数据拟合方法分别得到具有95%保证率的疲劳裂纹扩展参数。结果表明：本批次的WNQ570钢材具有良好的疲劳裂纹扩展性能,其中对接焊缝疲劳裂纹扩展速率高于母材;在应力强度因子幅值处于10 MPa·m^1/2～70 MPa·m^1/2的常规区间时,基于单试件数据点的处理结果对应的裂纹扩展速率明显高于基于成组数据点的处理结果;WNQ570的疲劳裂纹扩展速率随应力比增加而增加,疲劳裂纹扩展门槛值随应力比增加而降低。     

纯铜表面的连续摩擦压扭处理

提出了一种在纯铜表面得到大面积亚微米细晶组织及晶表面硬化处理的新工艺。在T2紫铜表面，利用连续摩擦压扭过程中产生的剧烈的剪切塑性变形，使材料表面形成了一层厚为0．1－0．2mm，晶粒直径200－300nm的亚微米细晶组织，表面硬度比基材提高了1倍，压扭头行走速度和转速对变形区晶粒细化和硬化效果影响显著。理论分析结果表明，在垂直于行走方向上加热能量和变形程度基本均匀。