土木工程中译英.doc

装订线扬州大学本科生毕业设计（论文）外文科技文献译文译文题目 智能传感技术用于土木 工程结构的结构健康检测学 院建筑科学与工程学院专 业(系)土木工程(建筑工程)学 号071402402学生姓名 陈金金日 期2011年5月30日 指导教师签名 日期 装订线扬州大学本科生毕业设计（论文）智能传感技术用于土木工程结构的结构健康监测【摘要】结构健康监测旨在开发自动化系统的在线连续监测、检验和在结构损伤检测中以最低的劳动参与。第一步先建立一个健康检测系统，是为了拥有具有长期稳定可靠性的一个层次的结构传感能力。智能传感技术包括光纤传感器、压电传感器、磁致伸缩传感器和纤维增强复合材料的自我诊断等方面的应用，在探讨各种各样的物理或化学因素对健康的影响方面，具有十分重要的功能的监测，因此应是耐用的寿命长的结构。特别是压电传感器与磁致伸缩传感器，既可作为传感器也可作为执行器，使结构健康检测成为一个积极的检测系统。这样的话，智能传感技术目前是可用的，并且可以被用于土木工程结构的结构健康检测。在本文中，用于土木工程结构的结构健康检测智能材料的应用/传感器是仔细检视的。主要焦点是在土木工程结构的评估研究的实验研究和现场的智能材料/传感器。1.介绍在任何国家土木工程基础设施通常是最贵的国家投资和资产。土木工程结构相较于其他的商业产品使用寿命长，但一旦安装后确实是维护和更换昂贵。而且，土木工程很少有原型，从材料的设计和建设每个结构通常是独特的。最重要的建筑包括桥梁、高层建筑、电力、核电、大坝。所有土木结构的年龄随着时间的推移而缩短。大部分的年龄缩短是由于材料老化、持续使用、超载、暴露环境恶劣、缺少足够的维护和检验方法不当造成的。所有的这些材料和结构的内部和外部恶化会引起人们重视，然后出现提高和进步。为了保证结构的完整性和安全性，土木结构必须被装备结构健康监测，旨在开发自动化系统的在线连续监测，检验和在结构损伤检测中以最低的劳动参与。一个有效的结构健康检测系统能实时、在线、检测各种缺陷和监控应变、应力、温度，所以，最佳的维护结构应该被执行以确保安全、耐用的使用寿命。一般来说，一个典型的结构健康检测系统包括三个主要的组件：一个传感器系统、数据处理系统(包括数据采集、传输和存储)和一个健康评价体系(包括诊断算法和信息管理)。建立的第一步是本系统拥有一个水平的稳定、可靠感应能力结构。因此，本文主要是关于结构健康检测系统的第一部分：传感系统通过智能材料/传感器所形成。智能材料/传感器，如光纤传感器、压电陶瓷传感器、磁致伸缩材料传感器、和纤维增强复合材料的自我诊断等方面的应用，在探讨各种各样的物理或化学因素对结构健康的影响方面，具有十分重要的功能的监测。所以磁流变液形状记忆合金经常被用于执行机构。他们在本文中就不介绍了。 例如，光纤传感器小，因此在他们被嵌入的土建结构中并不影响其性能特点。一种单纤维能在各种各样的地点利用遥感技术的多路复用或分布式有效的监控结构性能。他们被电磁干扰。光波适用于增加相对薄弱的信号的传播距离。压电和纤维增强复合材料传感器可以作为传感器和致动器，它使结构健康检测成为一个积极的监测系统。此外，他们可以有多种不同的尺寸，允许他们放置在随处可见的地方，甚至在远程遥不可及的地点，对不同类型的结构积极监控。结构健康检测的题材一直在迅速增长并在很大程度上，特别是在过去的几年中,本文关注的焦点在于回顾一个非常重要的先进多方面智能材料/传感器在土木工程结构的结构健康检测中的应用。它超出了本文的范围来描述所有参与的相关理论，或报告所有的实际应用例子。本文涵盖的几个主要方面是光纤传感器、压电陶瓷传感器、纤维增强复合材料的自我诊断和磁致伸缩传感器在土木工程应用。最后，本研究的结论为简要报道。2.光纤传感器有几种方法来划分光纤传感器。第一种划分光纤传感器的方法是基于光特性(强度、波长、状态或极化等)来调制这些具有普遍性的参数。第二种进行分类的方法是通过是否一个光纤传感器中的光传感段是改性的内部或外部纤维(内在或外在)。光纤传感器也可以算作是当地的、类似的分布式传感器,这取决于感应范围。该分类方法在这里适用。光纤传感器一般都是在现有的结构表面安装，或是在新建造民用建筑嵌入，包括桥梁、建筑和堤坝的屈服应变(静态和信息动态)、温度、缺陷(分层、裂纹和腐蚀),和氯离子的浓度。所得到的数据可以用来评估新建结构和修理的结构的安全性，以及诊断损害赔偿责任的程度。在这一节中, 光纤传感器在监测的应变、位移与缺陷和在民间工程结构的应用研究进展进行了综述。其他相关细节可能会在光纤传感器早期的评论被Merzbacher et al, Ansari and Leung发现。2.1应变与位移的监测实验室研究已澄清了一些基本的光纤传感器传感性能在土木工程结构中实际应用。De Vires et al.报道说,法布里-珀罗光纤传感器的输出信号与采用应变片得到考验的一个具体的品标本输出信号相比，光纤传感器比应变计有更好的信噪比。Quirion和Ballivy已经评估了法布里-珀罗的光纤传感器被嵌入在具体的气瓶时的性能。 图1中指出了测量得的相比，那些被振动电线压力表、电气应变规、LVDT测得的水平压力是略大于40%的混凝土的抗压强度。它可以被观察到，通过测量应变片和LVDT电器与测量光纤传感器很一致。Zhang et al进行了一次嵌入光纤传感器的混凝土板的反复荷载测试。4万次的频率和3赫兹是2赫兹被应用。幸存下来的传感器400万次的循环加载在2000应变振幅效应，并显示出良好的反应动态加载。Delepine-lesoille et al.设计了一种复核材料做的波浪状的传感器体，它能使有刚度的光纤和混凝土传递给对方。因此,应变集中减少，没有理论校正因子，不得不考虑理由。它也取得了无论是否在压加载的接触条件下对混凝土的连续粘结和允许对称拉伸下的响应。Zeng et al.使用一个基于布里渊单模纤维测量了应变沿一根1.65m钢筋混凝土梁的分布，称之为分布式光纤传感器，这能使测量温度和应变同时进行。在5厘米可分解的距离内应变测量精度达到5。Chen et al.比较了两种分布式传感器：时域反射器是基于有线传感器在一个电气电缆中传播电磁波和在布里渊散射的电气电缆和基于分布式光纤传感器中传播电磁波。他们被安放在附近80%规模梁柱钢筋混凝土的表面进行加固。结果表明，有线传感器可以测量的应变局部发生了一个重大的变化，尽管分布式光纤传感器在一段很长的距离上是慢应变的测量是好的候选。有线传感器测量应变分布只一秒或者更短，因此适用于动态信号的测量结果。然而，光纤传感器需要数分钟来完成一次测量。Wu et al.基于布里渊散射安装分布式光纤传感器来评价一个完完全全的预应力混凝土梁的性能。相比从应变片获得的测量结果，光纤传感器对拉伸应变的测量给了好的结果。但是，光纤传感器对压缩应变的测量包括一个相当大的误差，特别是在压缩应变很小的时候 。 在光纤传感器实际应用方面，加拿大卡尔加里贝丁顿小道桥是世界上第一个由光纤光栅传感系统和第一个在它的一些箱梁中使用碳纤维增强聚合物复合材料(CFRP)的预应力钢束公路桥梁。1993年，在这座桥中,几个肌腱在预应力后配备有总共18个光纤光栅传感器，15个传感器幸存了下来，而且功能正确。功能预应力钢筋的松弛行为从综合作用的痛苦，混凝土收缩徐变、死载荷桥面和水平钢进行了评价。他们发现，有一个更高的钢网应变松弛预应力混凝土箱梁比在碳纤维增强聚合物复合材料肌腱中，在桥开放通车八个月之后所有梁持续存在明显的应力松弛。一个动态的卡车试验表明,这些传感器6年后仍在手术,并没有结构性的问题被侦测到。首先，更重要的意义在于他们的研究，这个项目所显示的益处和优势的光纤传感技术的融合、创新的纤维增强材料和结构工程。FRP加固实时监控和组件可以增加用户信任他们在混凝土结构的申请，因为目前还没有对结构设计标准FRP的增援部队。另一方面，光学传感器可以保税在碳纤维加固的酒吧的表面上，所以，酒吧可以提供极佳的保护酒吧传感器的措施和他们的线索，在这个领域是一种非常方便的工具手段并且可以监测土木工程结构。目前，世界上有许多桥梁被装备光纤传感器传感系统。Benmokrane et al.将法布里-珀罗的光纤传感器应用于加拿大魁北克若夫尔桥梁的修复工程。他们被粘结在使用碳纤维增强聚合物复合材料的加固梁和钢梁以监控FRP加固的性能结构、甲板的应变和梁的应变。结果表明，在桥面维修服务条件下，温度是最重要的影响应变变化的因素。在桥开放通车后进行了一年的现场观测。使用三辆25吨校准卡车来评估其应变水平的FRP增援的时候，在FRP增援部队中测量的应变少于20，钢梁的应变少于120。Mufti et al.描述了程序嵌入光纤光栅传感器的加拿大同盟桥，但没有来自这些传感器的数据被报道。在泰勒桥，一共有63个光纤光栅传感器和26个电应变规被粘结到进行预应力的使用碳纤维增强聚合物复合材料的酒吧来监测在加固中由于施加负荷所引起的最大变形。但即使是应变规被适当地封闭,超过60%的电应变规故障是由于过多的水分造成蒸汽养护混凝土箱梁。当一辆36吨卡车通过一座桥，光纤光栅传感器的应变记录不到15。除了这些,在加拿大还有其它一些被伊希斯承办的示范工程。更多的细节,可以在http : / // field / main.htm? fieldprojects.htm.发现Bronnimann et al.报道了在瑞士光纤光栅被应用在两个桥梁上。在温特图尔的Storchenbrucke，光纤光栅被粘附在使用碳纤维增强聚合物复合材料的电线上来衡量悬架电缆的应变。光纤光栅从1999年3月1日起已经可靠地在2000应变水平工作了3年。另一种是在人行景观桥梁预应力碳纤维布置光导纤维电缆，那里是光导纤维在碳纤维拉挤过程中被嵌入到碳纤维增强聚合物复合材料电缆中。大部分的光纤光栅传感器被植入到遭受来自树脂的170-190C高固化温度和高水平的8000预应力应变，虽然他们两个由于脱粘而失败。在后来一年多时间里，他们有了令人满意的应变监测电缆、预应力过程中的锚头。Inaudi and Vurpillot使用他们的长标距SOFO传感器开发出一种新的方式来检索全球变形和桥梁的曲率。96 个SOFO，4米的评估长度被嵌入维何斯瓦桥的前两跨。基于一种物理模型，他们提出当静载荷作用在这座桥上时，全球水平和竖向变形总长度超过100米时应被计算，并且价值观与测量的数据通过量规很相配。类似地,Lutrive公路大桥曲率的变化通过卡车循环进行了监测。此外，现场位移监测的实施是在Siggenthal大桥建设的某些阶段，如混凝土不同的拱门，切除脚手架和自由站阶段的拱。Fuhr et al.描述了一座67m长光纤光栅长钢桁架桥跨越佛蒙特州的沃特伯里的威努斯基河的安装过程，46个光纤光栅被嵌入了甲板但是只有一个传感器被打破了。他们已经研制出一种基于频率区域的压力传感器来测量同时进行复用和振动。在美国佛蒙特州威努斯基河的水力发电厂是一个例子，在这种光纤光栅被吸收到的地方。在最初的低功耗测试设备一代，一种异常的频率被发现，这表明，一个主要的齿轮在电力火车失圆了。Ou and Zhou报道了他们在中国大陆将光纤光栅应用于桥梁监测的工作，特别是在哈工大的校园里。光纤光栅传感器被执行在超过10座实际桥梁来监测应变、应力和温度。例如，40个光纤光栅应变传感器、10个光纤光栅温度传感器，以及96个光纤光栅电缆传感器已经成功安装在中国天津市的永和大桥。对主要梁的应变、预应力筋的应力和在桥的电缆荷载试验进行了监测。Liu and Jiang研制出一种结构健康检测系统用于第一座横跨在中国长江的斜拉桥。同时基于光栅光纤的超载车辆识别系统和远程实时扣索索力的监测系统成功地施行了手术。Habel et al.将类似的分布式光栅光纤整合到岩石锚以监控应变沿固定锚固长度内的岩石的分布。为了提高EDER-dam的稳定性，在德国，一个垂直锚定大坝也被作了分析。这种类似分布的光栅光纤是定期地沿著光纤插入纤维拼接，每一段工作作为基于飞行时间测量的应变计。当这个锚被组装的时候，一个装备光纤光栅的芳纶杆被放置在锚的中心。来自光纤光栅的数据表明在结合的10m中只有2到2.5m固定的锚索的锚固长度，并且这个值随水位变化而变化。在这么恶劣的环境中还能存活下来的传感系统的锚力为4500 kN。光纤监测系统也在极端的老化条件下被引入土木结构。例如，Newhook et al.为大厅码头设计了一个光纤光栅的健康监控程序。这是在两种飞溅和潮汐区，受到热范围从冬天的-35C到夏天的+ 35C。不幸的是光纤光栅幸存的可能性不高。传感器嵌入后的一年，17个传感器中10个无法运作。传感器失败的主要原因是伴随着连接器的失败。制造缺陷、盐晶体或其他污物导致了粘接剂握住连接器鞘的光纤电缆的失败。在一般民用建筑，Fuhr et al.将光纤光栅安装在一个五层，65000平方英尺的混凝土结构，命名为“佛蒙特州大学的斯塔福德医疗大厦，佛蒙特州大学期间所负责施工阶段应力监测及混凝土养护以及内部裂缝传感。Kwon et al.使用基于布里渊的分布式光纤光栅在一幢建筑施工测得温度分布。1400米出纳给的光导纤维被安装在建筑物的表面。表面的温度变化，通常维持在4C一天。译文原文Smart Sensing Technologies for Structural Health Monitoring of Civil Engineering StructuresStructural Health Monitoring (SHM) aims to develop automated systems for the continuous monitoring, inspection, and damage detection of structures with minimum labour involvement. The first step to set up a SHM system is to incorporate a level of structural sensing capability that is reliable and possesses long termst ability. Smart sensing technologies including the applications of fibre optic sensors, piezoelectric sensors, magnetostrictive sensors and self-diagnosing fibre reinforced composites, possess very important capabilities of monitoring various physical or chemical parameters related to the health and therefore, durable service life of structures. In particular, piezoelectric sensors and magnetorestrictive sensors can serve as both sensors and actuators, which make SHM to be an active monitoring system. Thus, smart sensing technologies are now currently available, and can be utilized to the SHM of civil engineering structures. In this paper, the application of smart materials/sensors for the SHM of civil engineering structures is critically reviewed. The major focus is on the evaluations of laboratory and field studies of smart materials/sensors in civil engineering structures.1. IntroductionCivil engineering infrastructure is generally the most expensive national investment and asset of any country. In addition, civil engineering structures have long service life compared with other commercial products, and they are costly to maintain and replace once they are erected 1. Further,there are few prototypes in civil engineering, and each structure leads to be unique in terms of materials, design, and construction. The most important structures include bridges, high-rise buildings, power utilities, nuclear power plants, and dams. All civil structures age and deteriorate with time. The deterioration is mostly the result of aging of materials, continuous use, overloading, aggressive exposure conditions, lack of sufficient maintenance, and difficulties encountered in proper inspection methods. All of these factors contribute to material and structural degradation as internal and external damages emerge and coalesce, and then evolve and progress.To ensure structural integrity and safety, civil structures have to be equipped with Structural Health Monitoring(SHM), which aims to develop automated systems for the continuous monitoring, inspection, and damage detection of structures with minimum labour involvement 2. An effective SHM system can in real time, and online, detect various defects and monitor strain, stress, and temperature so that the optimum maintenance of the structures can be carried out to ensure safety and durable service life. In general, a typical SHM system includes three major components: a sensor system, a data processing system (including data acquisition, transmission, and storage), and a health evaluation system (including diagnostic algorithms and information management). The first step to set up this system is to incorporate a level of stable and reliable structural sensing capability. So, this paper is mainly related to the first component of the SHM system: the sensing system formed by smart materials/sensors. Smart materials/sensors, such as fibre optic sensors (FOS), piezoelectric sensors, magnetostrictive sensors, and self-diagnosing fibre reinforced structural composites, possess very important capabilities of sensing various physical and chemical parameters related to the health of the structures. Since shape memory alloys and magnetorheological fluids are often used as actuators, they are not introduced in this paper.FOS, for example, are small and therefore do not affect the performance characteristics of civil engineering structures in which they are embedded. A single fibre can efficiently monitor structural performance at various locations by using multiplexed or distributed sensing technologies. They are unperturbed by electromagnetic interference. Optical waves are suitable for long transmission distances of relatively weak signals. Piezoelectric and magnetorestrictive sensors can serve as both sensors and actuators, which make SHM to be an active monitoring system. Furthermore, they can come in a variety of sizes, allowing them to be placed everywhere, even in remote and inaccessible locations, to actively monitor the conditions of various types of structures.Since the subject matter of SHM has been growing rapidly and significantly over the last few years, the focus of this paper is on a critical state-of-the-art review of various applications of the above smart materials/sensors in SHM of civil engineering structures. It is beyond the scope of the paper to describe all the relevant theories involved, or to report all of practical applications examples. The paper covers the major aspects of fibre optic sensors, piezoelectric sensors, self-diagnosing fibre reinforced composites, and magnetostrictive sensors for applications in civil engineering. Finally, the conclusions of this study are briefly reported.2. Fibre Optic Sensors (FOSs)There are several methods to classify FOS. The first method of classifying FOS is based on the light characteristics (intensity, wavelength, phase, or polarization etc.) modulated by the parameters to be sensed. The second method classifies an FOS by whether the light in the sensing segment is modified inside or outside the fiber (intrinsic or extrinsic). FOS can also be classified as local (Fabry-Perot FOS or longgauge FOS etc.), quasidistributed (fibre Bragg grating) and distributed sensors (Brillouin-scattering-based distributed FOS) depending on the sensing range 3. This method of classification is adopted here. FOS are generally surface mounted on existing structures, or embedded in newly constructed civil structures, including bridges, buildings, and dams, to yield information about strain (static and dynamic), temperature, defects (delamination, cracks and corrosion), and concentration of chloride ions. The obtained data can be used to evaluate the safety of both new-built structures and repaired structures, and diagnose location and degree of damages. In this section, the application of FOS in monitoring of strain, displacement and defects in civil engineering structures is reviewed. Other relevant details may be found in early reviews of FOS by Merzbacher et al. 4, Ansari 5 and Leung 6.2.1. Monitoring of Strain and Displacement.Laboratory studies have clarified some basic sensing properties of FOS in applications for civil engineering structures. De Vires et al. 7 reported that Fabry-Perot FOS output signals comparedwell with the output signals obtained from collocated strain gauge in the test of a concrete cross-beam specimen, and FOS had a much better signal-to-noise ratio than the strain gauge. Quirion and Ballivy 8, 9 have evaluated the performance of the Fabry-Perot FOS when it was embedded in concrete cylinders. Figure 1 shows the measurements obtained with FOS compared to those by vibrating-wire gauges, electrical strain gauges, and LVDT when the level of stress is slightly over 40% of concrete compressive strength. It can be observed that measured strains with the FOS are in good agreement with those measured by the electrical strain gauge and LVDT. Zhang et al 10 conducted a repeated loading test on a concrete slab with embedded FOS. Four million cycles at a frequency of 2 Hz and 3 Hz were applied. The sensors survived the 4 million loading cycles at a strain amplitude of 2000, and showed good response to dynamic loading. Delepine-lesoille et al. 11 designed a kind of composite-made wave-like sensor body, which could make the stiffness of opticalfiber and concrete match to one another. Thus, strain concentrations were reduced, and no theoretical calibration factor had to be taken into account. It also achieved continuous bonding to the concrete and allowed a symmetrical response under tensile and compressive loadings whatever the contact condition was.Zeng et al. 12 measured the strain distributed along a 1.65-m reinforced concrete beam using one single-mode fibre, called as Brillouin-scattering-based distributed FOS which could measure temperature and strain simultaneously. Strain measurement accuracy reached 5 with the resolvable distance of 5 cm. Chen et al. 13 compared two kinds of distributed sensors: Electric Time Domain Reflectometry cable sensor that was based on the propagation of electromagnetic waves in an electrical cable and Brillouinscattering- based distributed FOS. They were mounted near the surface of the 80% scale beam-column reinforced concrete assembly. Results showed that the cable sensor could measure a significant change of strain locally while distributed FOS were good candidates for the measurement of slowly-varying strain over a long distance. The cable sensor measured a strain distribution in seconds or shorter and therefore applicable for dynamic signal measurements. However, FOS required several minutes to complete one measurement. Wu et al. 14 installed Brillouin-scatteringbased distributed FOS to evaluate the performance of a full-scale prestressed concrete girder. Compared with the measurement results from strain gage, FOS gave good results for tension strain measurement. But, FOS for compression strain measurement included a relatively large error, especially when the compression strain was small.In aspect of the practical applications of FOS, Beddington Trail Bridge in Calgary, Canada was the first bridge in the world to bemonitored by a fibre Bragg grating (FBG) sensing system and the first highway bridge to use carbon fibre reinforced polymer composite (CFRP) prestressing tendons in some of its girders. In this bridge, several tendons were equipped with a total of 18 FBG sensors after prestressing in 1993 15; 15 of sensors survived and functioned correctly. The relaxation behaviour of prestressing tendons from the combined effects of distressing, concrete creep and shrinkage, dead loads of the bridge deck and the posttensioning was evaluated. They found that there was a higher net strain relaxation in the steel prestressed concrete girders than that in the CFRP tendon, and continuing stress relaxation existed apparently in all girders eight months after the opening of the bridge to traffic. A dynamic truck test showed that these sensors were still operative six years later, and no structural problems were detected 16. Above all, the more important significance of their study lies in that this project demonstrated the benefits and advantages of merging optic sensing technology, innovative fibre reinforcement materials and structural engineering. The real-time monitoring of FRP reinforcement components can increase user confidence of their application in concrete structures, since there are no current design standards for structures with FRP reinforcements. On the other hand, the optic sensors can be bonded on the surface of the fibre reinforcement bars so that the bars can provide excellent protection of the sensors and their leads, and yield a very convenient means of instrumenting and monitoring civil engineering structures in the field.Currently, many bridges around the world have been instrumented with FOS sensing system. Benmokrane et al. 17 applied Fabry-Perot FOS to the rehabilitation project of the Joffre Bridge, Quebec, Canada. They were bonded to the CFRP grids and steel girders to monitor the performance of the FRP reinforced structure, strains of the deck and strains of the girder. The results showed that the temperature was the most important factor influencing the strain variation in the bridge deck under service conditions. The field measurements were carried out one year after the opening of the bridge to traffic. Using three 25-ton calibrat