Measuring the rate-dependent mode I fracture toughness of composites – A review

Composite materials are often subjected to mechanical impact causing delamination. For quasi-static loading, measuring the mode I fracture toughness has been standardized. However, for high-rate loading, additional challenges arise. Consequently, no standard test has yet been defined for measuring the mode I fracture toughness under high rates of loading. This article therefore reviews candidate tests for measuring the high-rate mode I fracture toughness. Strength and weaknesses of different specimen designs and test setups are shown. Different approaches to measuring crack growth and loads are presented. The different approaches are compared and recommendations are provided for measuring the mode I fracture toughness of composites under high rates of loading.     

超精密齿轮齿距累积总偏差测量装置的改进及其自动测量系统的设计

在明确齿轮齿距累积总偏差的相关概念的基础上,对相对测量法和绝对测量法进行进一步分类,并对各自的应用范围和特点进行分析.同时,遵循测量原理并采用高精度的元器件搭建了绝对测量法检测超精密齿轮齿距偏差的测量平台.通过Visual Basic 6.0语言设计合理的测量操作、图表处理及误差分析界面的过程,使操作简单,图表显示准确清晰,实现对1～2级超精密齿轮齿距累积总偏差测量装置的改进及其自动测量系统的设计.     

Algorithms for Measuring the Quality of Products and Their Characteristics

The principles of synthesizing algorithms for measuring the quality of products are presented on the basis of the mean arithmetic, geometric, harmonic, and other components. The fundamental provisions for measuring the initial information utilizing virtual standards are discovered. A method based on a numerical experiment is proposed for verifying the effectiveness, validity, and bias of algorithms for measuring the quality of products and expressions are given for a generalized algorithm for measuring the quality of products which makes it possible to obtain the most effective and unbiased results.     

大型机械工件高精度同轴度误差测量的新方法

本文介绍一种以标准钢丝作基准，借助于专用检具和电容测微仪，以非接触方法对方法对大型机械工件进行同轴度误差测量的新方法，同时，也对组成该检测系统的电容测微仪的标定方法和专用检具的设计特点作了概括说明。     

火炮后坐冲击振动对测控设备的影响分析

武器试验过程中,炮弹发射产生的巨大后坐冲击振动,会通过地基传递给测控设备,直接影响测控设备的精度,严重者甚至会毁坏测控设备。 因此,讨论火炮后坐冲击振动对测控设备的影响在实际工作中具有很 重要的意义。给出了火炮与测控设备组成系统的冲击振动模型,分析了火炮后坐冲击振动时对测控设备的影响,并提出了防振的一些措施。     

Synthesis of the measurement system on the machine tool

The design methodology of a 2½-dimensional measurement and inspection system realized on a machine tool using a touch trigger probe and measuring G codes is studied in this paper. The reliability of measuring results, the agility of measurement, and user friendliness are synthesized in the design process. Algorithms for calibration and compensation of measuring errors are proposed to ensure the measuring accuracy by using a laser interferometer and ring gauges. Classification of probing feedrates and a collision-check algorithm can reduce measuring time and implement stylus-fracture-free measurements. To improve the previous onmachine measurement processes, all functions required for measurement and inspection processes are constructed as measuring G codes with similar forms of machining G codes. The interactive measuring program generating tool, which can automatically generate measuring G codes, is developed and potted in a ROM of a CNC, and can be called to perform an operation by the CNC without interfacing with personal computers. The validity and effectiveness of the developed system are verified on a horizontal machining centre with a Fanuc 15MA.     

外圆磨削在线无损测控方法研究

本提出一种以气动测量原理实现的外圆磨削在线无损测控方法。阐述了测控方法、用简化的CMAC进行非线性校正的算法及气路和气电转换的原理。最后，简要介绍了在线测控存在的一些问题与对策。     

工程图学虚拟测绘模型系统的设计

研究了工程图学课程中虚拟测绘模型的设计.根据模型测绘教学的特点,确定了虚拟测绘模型的功能;设计了虚拟模型测绘流程;构建了模型测绘系统的结构.通过分析VRML节点的特性解决了系统的观察问题和模型点的选择提示及坐标的获得问题.设计了易于操作和理解的交互界面,实现了虚拟测绘模型系统.     

红外测量系统动态测角误差分析

介绍了一种光电测量设备红外测量系统动态测角误差检测方法，该方法是通过将红外系统测量数据与主摄影系统测量数据相比对，并对红外系统与主摄影系统平行度进行了定点修正，且与主摄影系统动态测角误差合成后实现的，叙述了检测设备的组成、检测方法、数据处理过程及测量结果，这一检测方法适用于具有摄影系统的光电测量设备的红外系统和电视系统等其它分系统动态测角误差的检测。     

柔性薄状物体的测量

对于易变形、柔性、薄状物体，采用常见的装夹方法在“万工显”上是很难测量的。本文详细叙述了利用“万工显”测量有关此类物体的新方法，并进行了测量误差分析，指明了测量中应注意的问题，对于扩展“万工显”的测量范围及提高测量精度具有借鉴意义。     

双光束法测速度时测量角产生的影响

本文讲述了利用双光束法进行无接触流速的测量。并着重讨论和分析了不同测量角所带来的不同影响,以及最佳测量角的选定。     

远红外光光栅光谱仪测量误差分析

采用平面闪耀光栅作为光谱元件的远红外光谱测量原理,分析了四种主要的重复性误差:光栅常数制造误差、零点标定误差、转角测量误差、入射光束与衍射光束的夹角测量误差。 并分别以112.5mm、40.05mm、25mm和12mm的四种闪耀波长为例,计算出了它们的误差传递系数曲线,根据误差传递系数对光谱仪进行误差分配,分析和计算表明:当光栅转角测量精度为1,光栅常数误差为0.5mm时,光谱仪可以满足l/100的波长测量误差要求和l/200的波长重复性测量误差要求。     

工业大尺寸测量仪器的溯源现状及发展趋势

大型工业产品及装备制造的信息化和全球化需要高精度大尺寸测量仪器作计量保障.本文介绍了现有工业大尺寸测量仪器的发展现状和应用特点,对现有的校准技术和溯源形式作了总结与分析,并展望了今后大尺寸测量仪器的溯源形式.     

光电技术在合肥光源束测量系统中的应用

介绍了光电技术在合肥同步辐射加速器束流测量系统中的应用。介绍了合肥 2 0 0 Me V电子直线加速器利用光电二极管阵列的能谱测量系统、合肥 80 0 Me V电子储存环利用 CCD技术的束流截面测量系统以及利用单光子计数法测量束团纵向精细结构。本文给出了测量结果。     

肺功能仪校准方法

简要阐述了肺功能仪校准的社会意义,介绍了肺功能测量的临床诊断参数,分析了肺功能仪校准规范的主要内容,并结合规范详细说明了肺活量、用力肺活量、呼气峰值流量、最大分钟通气量、气体分析器的校准方法,提出了肺功能仪校准应注意的问题。     

Block diagrams for information measuring systems of physicochemical composition and substance properties

Block diagrams for information measuring systems of physicochemical composition and substance properties are considered and it is noted that within their composition there should be first level systems that are either independent measuring systems, or measuring sub-systems of a second level system, or management information measuring systems. Translated from Izmeritel’naya Tekhnika, No. 10, pp. 57–60, October, 2008.     

壁稳弧等离子体温度测量

介绍壁稳弧等离子体温度测量方法的理论依据和测量装置,并进行了误差分析。     

便携式激光表面粗糙度测量仪

介绍了一种基于光散射原理的便携式激光表面粗糙度测量仪。它采用半导体激光器光源，以元心光路结构接收、处理经粗糙表面调制的散射光带，成功地解决了粗糙度测量精度高低与测量范围大小相矛盾的问题。仪器结构简单、操作方便、测量效率高，精度能满足生产实际的需要。