大量程光纤光栅应变传感器的开发与应用

发布时间：2018-08-15 18:28

【摘要】：对大型复杂工程结构进行实时健康监测,及时识别结构的累积损伤并评估其使用性能和寿命,建立相应的安全预警机制对可能出现的灾害提前预警,不仅对提高结构的安全性和可靠性具有重大的科学意义,并且可以降低结构的运行和维护费用,具有可观的经济价值。实时监测结构的健康状况并评估其安全性已经成为未来工程建设的必然要求,也是21世纪人类亟待解决的重要课题。本文针对土木工程中一些结构在实际工作状态下应力应变比较大,现阶段光纤光栅传感器还不能满足这类工程监测需求的现象,开发出能够满足这类工程监测需求的大量程光纤光栅应变传感器。同时对这种新型传感器进行了试验标定和应用,得到了传感器相关的测量精度和误差范围。本文在已有光纤光栅应变传感器的原理基础上进行技术创新,建立了大量程光纤光栅应变传感器的基本理论。在这种基本理论的指导下设计出了一种新型的传感器封装形式。与以往的光纤光栅应变传感器相比,这种新型传感器能够将待测构件传来的应变通过传感器成倍数的削弱后再传递给光纤光栅,保证了光纤光栅承受的应变不超过其极限抗拉应变,增加了传感器的应变测试范围。结合传感器的应变传递过程,分析出了导致实际封装的传感器参数与设计值之间存在偏差的原因,并标定出传感器的实际测试量程和精度。这种新型光纤光栅传感器体积小、结构简单、稳定性和可靠性良好、便于安装,具有光纤光栅传感器所有的优点。针刘不同形状的待测构件,可利用不同形式的传感器支座,使传感器能够有效监测到构件的受力状态。本文成功的将大量程光纤光栅传感器安装到预应力钢绞线表面,有效地监测到了钢绞线张拉过程中的受力状态。由于钢绞线不同于普通钢筋,不能将传感器焊接到钢绞线上,本文还设计了一种弧形支座,便于大量程光纤光栅应变传感器安装到钢绞线上。结合钢绞线的受力形式,分析了传感器测量的应变值与实际值之间的关系,提出修正偏差的方法。本文课题组成员利用光纤光栅混凝土应变传感器和光纤光栅温度传感器,对沈阳市文化艺术中心主体混凝上结构进行了施工阶段的监测,并在监测过程中解决了光纤光栅传感器工程应用存在的一些难题,取得了良好的监测结果。为施工质量的控制和安全施工提供了宝贵的依据。
[Abstract]:Real time health monitoring is carried out on large and complex engineering structures to identify the cumulative damage of structures and evaluate their service performance and life in time, and to establish a corresponding safety warning mechanism for early warning of possible disasters. It is not only of great scientific significance to improve the safety and reliability of the structure, but also can reduce the operating and maintenance costs of the structure, which is of considerable economic value. Real-time monitoring of the health status of the structure and evaluating its safety has become an inevitable requirement of future engineering construction, and is also an important subject to be solved urgently in the 21 ~ (st) century. In view of the fact that some structures in civil engineering are relatively large in stress and strain under the actual working conditions, the fiber Bragg grating sensors can not meet the needs of this kind of engineering monitoring at the present stage. A large number of fiber Bragg grating strain sensors have been developed to meet the needs of this kind of engineering monitoring. At the same time, the new sensor is calibrated and applied, and the measurement precision and error range of the sensor are obtained. In this paper, based on the principle of fiber Bragg grating strain sensor, the basic theory of a large number of fiber Bragg grating strain sensors is established. Under the guidance of this basic theory, a new type of sensor package is designed. Compared with the previous fiber Bragg grating strain sensor, this new type of sensor can multiply the strain from the component to be measured and then transfer it to the fiber Bragg grating. It ensures that the strain of fiber grating does not exceed its limit tensile strain and increases the range of strain measurement of the sensor. Combined with the strain transfer process of the sensor, the causes of the deviation between the sensor parameters and the design value are analyzed, and the actual measurement range and accuracy of the sensor are calibrated. The new fiber grating sensor has the advantages of small size, simple structure, good stability and reliability, easy installation and has all the advantages of fiber grating sensor. Different types of sensor supports can be used in different shapes of the components to be tested, so that the sensors can effectively monitor the force state of the components. In this paper, a large number of fiber Bragg grating sensors are successfully installed on the surface of the prestressed steel strand, and the stress state during the tensioning process of the steel strand is effectively monitored. Because the steel strand is different from the common steel bar, the sensor can not be welded to the steel strand. In this paper, a kind of arc support is also designed, which is convenient for a large number of fiber Bragg grating strain sensors to be installed on the steel strand. Combined with the force form of the steel strand, the relationship between the strain value measured by the sensor and the actual value is analyzed, and the method of correcting the deviation is put forward. The members of this paper made use of the fiber Bragg grating strain sensor and the fiber grating temperature sensor to monitor the structure of the main body of Shenyang Culture and Art Center during the construction stage. In the process of monitoring, some problems in the application of fiber grating sensors are solved, and good monitoring results are obtained. It provides valuable basis for construction quality control and safe construction.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU317

【相似文献】