Optical fibre sensors for health monitoring of bonded repair systems

In the aircraft industry the use of externally bonded composite repairs has become an accepted way of repairing fatigue, or corrosion, damaged metallic structural components. However, current NDI and damage assessment techniques for composite repairs are passive and generally performed on ground. The challenge is to develop new techniques utilising recent analytical and experimental tools. This report examines the use of optical fibre sensors. Optical fibres offer a means of monitoring the load transfer process in these repairs, and can therefore be used to provide an indication of the integrity of the repair. This paper describes the use of an array of fibre Bragg grating strain sensors (FBGs) for the in situ monitoring of bonded repairs to aircraft structures and, in particular, the monitoring of crack propagation beneath a repair. In this work the FBGs have been multiplexed using a combination of wavelength and spatial techniques employing a tunable Fabry–Pérot (FP) filter to track individual gratings. The multiplexed FBGs were then surface-mounted on a boron–epoxy unidirectional composite patch bonded to an aluminium component. The sensors were located so as to monitor the changing stress field associated with the propagation of a crack beneath the patch. The ability of relating experimental results to sensor readings is then confirmed using both a thermo-elastic scan of the patch and 3D finite element analysis.     

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.     

VB与MATLAB混合编程在动态测量误差处理中的应用

本论文提出了将VB与MATLAB混合编程的方法应用于动态测量处理中,以双啮仪测量圆柱齿轮的径向综合误差为例编制了相应的程序,可快速有效的进行数据处理,其结果在VB界面上能直观的显示出来。从而提高了动态测量误差处理的速度和计算精确度。     

基于FPGA的光纤传感解调数据处理系统

为解决目前光纤传感测试领域存在的组网测试采集量大的问题,设计并实现了一种基于FPGA的大数据量实时处理系统,详细介绍了系统的硬件构架和关键模块设计,重点描述了FPGA通过寻峰模块和交叉读写缓存模块实现大数据量的实时处理方法。在FPGA中加入寻峰模块,从大量光谱数据中选取有效数据,减少传输的数据量,并通过交叉读写缓存保证数据传输的连续性,将筛选后的有效数据发送至上位机。通过实验对该系统的实际应用性能进行验证,结果表明该系统能够有效满足基于光谱采集的多通道光纤传感解调数据处理要求。     

Optical Generation and Detection of Ultrasound

Abstract: This is a review of the optical generation and detection of ultrasound on work carried out in different optical detection techniques at the Strathclyde University. We start by pointing out some limitations of conventional ultrasonic transducers and show how the use of optical-based transducers can overcome them. After explaining how laser generation of ultrasound works, we will describe and compare the advantages and disadvantages of three optical detection techniques. Finally, we describe applications in which optical ultrasound techniques appear to have a promising future.     

航管二次雷达测试仪信号处理算法研究

针对航管二次雷达地面询问机系统开场测试情况,讨论了一种基于航管二次雷达测试仪信号处理的抗汇叠、去异步干扰算法。该测试仪将接收到的询问信号通过包络检波和运算放大后,送到A/D卡进行数据采集,通过抗汇叠、去异步干扰信号处理算法,分离出各个询问信号,并对其进行测试、分析和判别。结果证明,该测试仪信号处理算法可分离出多部雷达的信号,在实际的工程中取得了较好的检测效果和应用。     

Some features of the procedure for measuring electric power by automated measuring systems

The components of the error of electric-power loss are investigated. The results can provide a basis for a standard document regulating the procedure for measuring electric power using measuring systems. __________ Translated from Izmeritel’naya Tekhnika, No. 4, pp. 62–64, April, 2006.     

炉温均匀性测试数据处理系统的设计与实现

在航空工业中,对炉温的均匀性要求比较高。文章所设计的数据处理系统作为炉／槽温度均匀性测试装置的软件部分,实现了对测量数据的自动修改、过滤及参数计算等功能。该系统实现中用到了PB与Excel的数据通信等关键技术。本系统已应用在西飞的军民机生产、转包生产、民品生产等项目中。     

Automated information measurement systems in the housing and utilities sector

Stages in the development and prospects for using measuring systems are considered. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 63–67, July, 2007.     

真空预冷实验机及其数据采集处理系统

介绍了VAC-0.2型真空预冷实验机结构及其基本性能.对它的数据采集处理系统进行了详细分析.试验证明该数据采集处理系统测量精度高,操作方便,充分满足了真空预冷实验要求.     

多普勒全场测速技术中图像及数据处理

介绍了多普勒全场测速技术(DGV)图像及数据处理的方法和过程.图像处理过程中,经背景去除、灰度校正、几何校正等,能够有效滤除实验环境中的背景光,修正不同相机之间感光度不同的影响,校正流场区域在图像中的几何形状的形变.针对转盘测速实验图像进行处理,得到的速度分布与实际速度分布吻合较好,证明所采用的方法是可行的.     

采用薄膜传感器的树脂基复合材料热压罐工艺密实压力测试方法

针对树脂基复合材料层板热压罐成型工艺,采用薄膜压力传感器建立了密实压力在线测试系统,用于监测成型过程中复合材料所受密实压力的大小和分布。研究了密实压力测试系统在热压罐工艺条件下的适用性,在此基础上以该系统为测试手段,研究了热压罐工艺下L形碳纤维/环氧树脂复合材料层板的密实压力变化规律及模具形式的影响。结果表明: 所建立的密实压力测试系统具有较高的准确性和动态响应性,能够测试高温条件及曲面位置的密实压力,满足复合材料热压罐成型过程中密实压力的在线测试要求; L形复合材料层板成型过程中拐角区与平板区的密实压力随热压罐压力增大而增加,但增加速度和最终大小不同,阳模成型时拐角区密实压力高于平板区,阴模成型时拐角区密实压力小于平板区和外加压力,表明曲面结构与平板结构的密实行为具有差异性。     

AFM observation of surface topography of fibre Bragg gratings fabricated in germanium–boron codoped fibres and hydrogen-loaded fibres

This paper reports the measurement of the surface topology of optical fibres containing a fibre Bragg grating (FBG) using an atomic force microscope (AFM). The AFM observation was made on FBGs fabricated via the phase mask technique in germanium–boron codoped optical fibres, in hydrogen-loaded germanium–boron codoped fibres and in standard telecommunications optical fibres. The surface images reveal that a spatial corrugation pattern was induced by the UV-irradiation, with a period that is half of the period of the phase mask. This UV-induced surface structure was found only on the side of the fibre facing towards the incident UV-irradiation and did not appear on the rear surface. The AFM probe scanned a 10×10 μm² surface area at seven sites along the 6.0 mm length of fibre that was exposed to the UV-irradiation. The amplitude of the spatial corrugation pattern observed on the AFM image was quantified for each site. It was found that the amplitude in a range of 0.7–3.2 nm was a function of UV-laser intensity distribution and the type of fibre. Hydrogen loaded optical fibres exhibited a corrugation with an amplitude twice as large as that observed in the Ge–B doped fibres that were not hydrogen-loaded. This correlates with the increase in photosensitivity produced by the hydrogen loading. A similar UV-induced spatial corrugation was also observed on standard telecom fibres, but without inducing the refractive index change in the fibre core. The observation of surface topology provides an insight into the structural changes induced during FBG fabrication. UV-induced densification and laser ablation could account for the formation of the surface troughs.     

High efficiency panchromatic photopolymer recording material for holographic data storage systems

Studies carried out to gauge the potential of a metal-ion doped panchromatic photopolymer recording material for application in real-time holographic data storage is presented. The photopolymer films are spin coated on glass plates to ensure better surface uniformity. Volume holographic transmission gratings with peak diffraction efficiency of 80% could be stored in the photopolymer films of 100 μm thickness. An efficiency of 70% is achievable even for gratings recorded with exposure energy as low as 10 mJ/cm². A checkerboard pattern data page recorded in the photopolymer film using a defocused 4-f recording geometry could be reconstructed with good image quality. The experimental results illustrate the competency of the developed photopolymer for holographic data storage applications.     

数据处理常用数表的替代公式

数据处理与统计中查各种系数的数表很不方便,建立了一系列简化公式以替代这些数表.     

Analysis of production planning and control (PPC) systems as an efficient combination of information activities

Production planning and control (PPC) systems with their planning structures, submodules and the information and data processing show similarities with the structures of multistage multi-product manufacturing. So, here the attempt is being made on the basis of the activity analysis to integrate the information characteristics of goods involved in production with regard to the requirements of production planning into the inputoutput relationships and to represent them in the form of so-called informational production functions. Based on the formulation of information activities efficiency criteria are developed, which allow to evaluate the data processing in PPC-modules and thus to eliminate inefficient activities. A concrete application to dynamic lot sizing demonstrates the procedure.     

Assurance of automated information measurement systems for commercial accounting of electrical energy

The main content of new documents for metrological provision of measuring systems for electrical energy is considered. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 67–69, July, 2007.     

三坐标测量机的数据处理和分析

数据处理和分析是三坐标测量机应用的核心工作，而基于统计过程控制的SPC技术，则是测量机应用的高级阶段，SPC技术应用的基础性工作是对大量数据的汇总处理。本文提出了一种利用程序方法对数据进行汇总的数学模型和编程思路，结合工作中的经验，对SPC技术的实际应用进行了一些粗浅的探讨。通过使用这些技术和方法，可以实现数据采集、数据处理和数据分析的全程自动化。     

Block diagrams for measuring systems of substance physicochemical composition and properties with “simple” measuring channels

Block diagrams of measuring systems for physicochemical composition and properties of substances with “simple” measuring channels are considered. The interrelationship of technical and economic indices and their block diagrams is demonstrated, and its features are noted. Translated from Izmeritel’naya Tekhnika, No. 1, pp. 67–71, January, 2009.