FBG传感技术在大坝安全监测中的应用研究

在阐述光纤布喇格光栅(FBG)传感器工作原理的基础上，研究了光纤光栅传感器在混凝土结构中的埋设技术。通过对混凝土结构施加载荷，探讨了光纤光栅传感器对混凝土结构内部应力应变变化的监测技术，并与振弦式应变传感器的监测结果进行了对比分析。结果表明：FBG传感器具有更高的精度和灵敏度，可实现绝对数值测量，抗干扰能力强，结构简单，长期稳定性好，能实现实时、在线监测。该技术在大坝安全监测方面具有广泛的应用前景。     

基于白光干涉原理的光纤传感技术——Ⅰ.光纤传感器与智能结构

概述了用于智能结构和材料监测的光纤传感技术,阐述了对建筑结构进行监测的原因和将光纤传感器用作结构健康监测的理由。众所周知,很多光纤传感器已经成功地应用到了智能结构监测领域。本研究一直关注白光干涉式光纤传感器技术及近20年来此类传感器的发展。由于白光干涉式光纤传感器在智能结构监测尤其是大型民用建筑物监测中的独特优点,因此具有较大的发展与应用潜力。     

光纤传感器阵列监测建筑结构应变的系统设计

提出了一种用光纤传感器阵列监测建筑结构应变的方法。并且应用了多模光纤传感器和四FBG传感器，使测试结果更可靠。设计了用FBG传感器阵列监测500m空间范围的系统，使分辨率达1．6με。同时讨论了光纤传感器的封装与贴置方法。     

新型光纤Bragg光栅锚索预应力监测系统

针对预应力锚索检测的问题，在分析预应力传感器研究现状的基础上，提出了采用光纤Bragg光栅传感技术进行锚索监测的新方案，详细介绍了光纤Bragg光栅锚索预应力监测系统的工作原理及主要构成、进行了工程现场与常规的电测技术的对比实验。结果表明：光纤Bragg光栅传感器具有高的精度，抗干扰能力强，结构简单，长期稳定性高，实现实时、在线监测。     

桥梁加固的光纤光栅传感监测评估研究

光纤光栅传感技术具有抗干扰能力强、长期稳定性好、绝对值测量、可以实现准分布式长期监测等优点。根据光纤光栅传感器的应变传感特性标定试验 ,以及在土木工程加固监测中的试验结果 ,在武黄高速公路的典型桥涵中布设光栅传感器 ,评估高速公路桥梁加固效果以及对这些桥涵结构进行长期监测。     

光纤传感器在复合材料固化监测中的应用

光纤传感器代表一种崭新的传感技术，适用于众多场合，根据传感原理，对应用于复合材料固化监测的光纤传感器进行了概述，分别介绍了它们的结构，传感机理及应用方法，并总结了光纤固化监测传感器在工程中广泛应用急待解决的问题。     

光纤光栅用于混凝土结构监测的研究

基于重大工程结构健康监测的高精度要求，光纤光栅传感技术应运而生。文中首先讨论了光纤光栅用于混凝土结构健康监测的两项关键技术：光纤光栅传感器的安装工艺和消除光纤光栅交叉的敏感性，然后在粘钢加固混凝土立柱上进行了加载试验研究，同时与粘贴在相同位置的电阻应变片进行了对比，实验结果证明了用光纤光栅传感器进行结构健康监测这一方法的可行性和先进性。     

基于光纤荧光的电力设备温升在线监测系统研究

电气设备温度的在线实时监测问题已日益受到广泛重视.由于测温场合条件特殊，给温度测量造成一些实际的困难，在寻求温度传感器的其他替代手段的所有研究活动中，荧光光纤温度传感器以其抗电磁干扰能力强、体积小、耐高压、耐腐蚀等优点正日益受到重视.介绍了高压电气设备温升在线监测应用研究现状及两种国外基于光纤的温度监测系统.重点介绍了新设计的一种基于光纤荧光的多路温度在线监测系统，详细分析了其工作原理并介绍了该装置的总体结构，通过实验给出了其技术指标.     

光纤传感器在混凝土结构中的相容性研究

针对土木工程领域中光纤传感器与混凝土结构的相容性问题,在理论分析和研究的基础上,提出一系列提高二者相容性的方法,并研制了一种新型的光纤传感器。实验研究表明,采用新型光纤传感结构和环氧保护层方案,不仅使传感器能适应恶劣的施工环境,而且能较好地实现对裂纹产生、扩展、断裂的监测。并在大变形情况下传感器不失效,具有较好的相容性,能够满足实际工程的。     

基于光纤传感技术的往复式压缩机振动监测研究

基于光纤(Bragg)光栅传感技术的优点,提出了往复式压缩机的光纤光栅振动监测方法。设计了一种"L"型结构的FBG振动传感器,并对传感器及其系统进行了实(试)验研究。结果表明,该传感器的工作频率范围为3～60Hz,灵敏度为86pm/(m.s-2),加速度测量范围大于25m/s2,其系统具有抗电磁干扰和本质安全防爆的特点,长期稳定性好,易于实现远程、在线测量,很好地满足了往复式压缩机振动监测的需要。     

Advances in fibre optic based geotechnical monitoring systems for underground excavations

Geotechnical stability is a major concern for the long-term safety and integrity of underground infrastructures such as tunnels, railway stations, mine shafts and hydraulic power chambers. An effective geotechnical monitoring system is able to provide adequate warning to underground personnel prior to any unexpected major geotechnical failure. This paper reviews the conventional geotechnical monitoring sensors and the emerging Fibre Optic Sensing(FOS) techniques, pointing out their unique features and major differences. Recent advances in various FOS based monitoring systems, including Brillouin time domain distributed optical sensors and fibre Bragg grating(FBG) sensors, are investigated through a critical review of the laboratory studies and field applications used for underground geotechnical monitoring. Particular emphasis is given to fibre packaging, temperature compensation, installation methods and instrumentation performance in the underground environment. A detailed discussion of the advantages and limitations of each FOS monitoring system is also presented in this paper.     

光纤应变传感器在振动检测和安全评估中的应用

介绍了一种利用光纤应变传感器进行动载作用下构件安全性检测的方法,以国内某过山车基础支撑为例,介绍了光纤应变传感器的安装和使用方法,并通过对传感器采集到的应变数据进行分析,结合其他现场检测数据,对受测构件安全性给出了评价.     

Progress and trend of sensor technology for on-line oil monitoring

Oil monitoring constitutes an important and essential component of condition monitoring technologies and has distinguished advantages in revealing wear, lubrication and friction conditions of tribo-pairs. Newly developed on-line/in-line oil monitoring technologies extend the merits into real-time applications and demonstrate significant benefits in maintenance and management of equipment. This paper comprehensively reviews the progress of on-line/in-line oil monitoring techniques including sensor technologies, their scopes and industrial applications. Based on the existing developments and applications of the sensors for oil quality and wear debris measurements, the trends for future sensor developments are discussed with focuses on accurate, integrated and intelligent features along with exploring a fundamental issue, that is, acquiring the knowledge on degradation mechanisms which has not received sufficient attention until now. Current status of applications of on-line oil monitoring is also reviewed. Although limited reports have been found on this topic, increasing awareness and encouraging progress in on-line monitoring techniques are recognized in applications such as aircraft, shipping, railway, mining, etc. Key fundamental issues for further extending the on-line oil monitoring techniques in industries are proposed and they include long-term reliability of sensors in harsh conditions, and agreement with fault or maintenance determination.     

带状双芯光纤及其双折射特性分析

试制了一种带状双芯光纤.根据带状双芯光纤的结构特点,给出了其在制作光纤器件及光纤传感器上的典型应用.利用有限元软件仿真分析了带状双芯光纤的双折射特性,通过调整光纤模型的结构参数,给出了该光纤双折射随光纤包层厚度的变化而改变的趋势,对于新型特种双芯光纤的设计和改进具有一定的参考意义.     

FAST 30m模型健康监测系统

为了有效地评定结构安全性和使用性,研究并设计了大射电望远镜FAST(Five-hundred-meter Aperture Spherical radio Telescope)30 m缩尺模型结构健康监测系统.针对FAST30 m模型结构特性,确定健康监测系统的组成、功能和监测内容;依据适用条件、性价比等对传感器优化选型,计算结构"热点应力"位置并采用概率灵敏度分析方法计算应力变化对结构刚度影响最大位置,以此优化应力传感器测点位置,采用有效独立方法优化计算加速度传感器测点位置;提出了FAST30 m模型结构的安全评定及预警方法;综合运用Matlab、Ansys和Labview等软件设计了健康监测系统.FAST30 m模型健康监测系统能协调运行,并应用于FAST30 m模型索网结构张拉成形施工过程中,实现了预期设计功能.     

Substructure isolation and damage identification using free responses

Structural health monitoring (SHM) has become a hot and intensively researched field in civil engineering. Thereinto, damage identification play an important role in maintaining structural integrity and safety. Many effective methods have been proposed for damage identification. However, accurate global identification of large real-world structures is not easy due to their complex and often unknown boundary conditions, nonlinear components, insensitivity of global response to localized damages, etc. Furthermore, global identification often requires lots of sensors and involves large number of unknowns. This is costly, rarely feasible in practice, and usually yields severely ill-conditioned identification problems. Substructuring approach is a possible solution: substructuring methods can focus on local small substructures; they need only a few sensors placed on the substructure and yield smaller and numerically much more feasible identification problems. This paper proposed an improved substructure method using local free response for substructure damage identification. The virtual supports are constructed by Substructure Isolation Method (SIM) using the linear combination of the substructural responses. The influence of the global errors is isolated by adding the virtual supports on the main degree of freedoms (DOFs) of the substructure. Through the correlation analysis, the substructural modes are selected and used for damage identification of the substructure. A plain model of cable stayed bridge is used for the verification of the proposed method.     

基于计算可靠度的现有RC结构构件的安全等级划分研究

在考虑现有RC结构构件的后续使用年限和抗力衰减的基础上,利用计算的民用RC结构构件在不同情况下的可靠指标,研究了构件计算的可靠指标与其安全等级之间的关系;将现有RC结构构件的可靠指标的定量计算与鉴定时的分级定性评定结合,经过计算和与设计规范的要求比较,给出了安全等级划分评定时的计算可靠指标标准.提出的民用建筑结构RC构件鉴定时安全等级划分评定的量化方法,可应用于现有结构构件的鉴定中;得出的鉴定等级安全性与设计规范的安全性是一致的,实现了民用结构RC构件鉴定的定量计算.