Development of Structural Health Monitoring System by using Distributed Optical Fiber Sensing

结构炉底监测已成为全世界基础设施工程界最为关注的问题之一。要实施成功的结构健康监测计划，需要选择和放置适合测量影响结构系统性能和健康的关键参数的传感器。光纤传感器在许多情况下提供了灵活性和实用性，传统的传感器要么不能进行适当的测量，要么无法进行适当的测量。此外，光纤传感器能够进行分布式测量，并可以进行串联多路传输，这反过来又减少了穿过结构的导线数量。在过去的二十年里，许多光纤传感器类型和配置已经面世，包括本地化、长规和分布式传感器。基于分布式和串联式光纤传感技术的大尺寸结构和DIV…结构健康监测系统的建立建筑材料的更高强度是一个充满期待的激烈话题。本研究致力于发展基于分布式和串联式多路复用光纤传感技术的混凝土等基础设施结构健康监测、损伤表征和诊断等关键技术。1)基于布里渊散射的分布式传感(BOTDR等)应变和裂纹分布的测量原理和特点。都被调查和检查得很清楚。此外，本文还提出了一些有效的安装方法，以提高空间分辨率和精度，滤除测量噪声。另一方面，本文还提出了一种基于串联多路FBG传感器的分布式传感方法，该方法将FBG传感器设计为长度可变的长规结构。2)对基于上述分布式光纤传感方法的不同类型结构(包括FRP加固的PC梁和梁柱组件)的静力和动力响应的分布式和远程监测进行了研究和讨论。3)针对具有复杂非线性或裂缝分布的框架、桥梁和混凝土隧道衬砌，提出了基于神经网络和非线性有限元的分布式损伤表征方法。此外，还对开发相应的传感-计算-诊断系统进行了一些尝试。较少

Structural hearth monitoring (SHM) has become one of the most particular concerns of infrastructure engineering community worldwide. Implementation of successful SHM programs requires selection and placement of sensors suitable for measurement of key parameters that influence the performance and health of the structural system. Fiber optic sensors provide flexibility and practicality in many situations, where the conventional sensors are either not capable of feasible to make the appropriate measurements. Furthermore, fiber optic sensors are capable for making distributed measurements and can be serially multiplexed and this in turn reduces the number of leads running through structures. Many fiber optic sensor types and configurations have become available over the past two decades, including localized, long gauge and distributed sensors. The establishment of SHM systems based on distributed and serially multiplexed fiber optic sensing technologies for large size of structures and div … More ersity of construction materials is an intense subject with great anticipation. This study is devoted in developing some key sensing, damage characterization and diagnostic methods for SHM of infrastructure such as concrete structures based on distributed and serially multiplexed fiber optic sensing technologies. It can be summarized as follows :1)The measurement principles and characteristics of strain & cracking distributions for brilliouin scattering based distributed sensing (BOTDR etc.) are investigated and examined clearly. Moreover, some effective installation approaches to improve the spatial resolution and accuracy and to filter the measurement noise are proposed in this study. On the other hand, a distributed sensing approach based on serially multiplexed FBG sensor is also proposed in which the FBG sensors are designed as a long-gauge manner with a variable gauge length.2)Distributed and remote monitoring both for static and dynamic responses of different types of structures including FRP-strengthened PC girder and beam-column assembly based above proposed distributed fiber optic sensing methods are investigated and discussed.3)Some kinds of distributed damage characterization methods based on neural networks and nonlinear FEM for frame, bridge and concrete tunnel linings with complex nonlinearity or crack distribution are proposed. Moreover, some attempts of developing the corresponding sensing-computational-diagnostic systems are made also in the study. Less