Yang Jing, Hou Peng, Yang Caiqian, Yang Ning
Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 210096, China.
College of Civil Engineering & Mechanics, Xiangtan University, Xiangtan 411105, China.
Sensors (Basel). 2021 May 17;21(10):3492. doi: 10.3390/s21103492.
A long-gauge fiber Bragg grating (FBG) strain sensor with enhanced strain sensitivity is proposed, which is encapsulated with two T-shaped metal blocks. Its fabrication method is described briefly, and the strain sensitivity can be flexibly adjusted through changing its packaging method. A series of experiments are carried out to study the packaging and its sensing properties. The experimental results show that the strain and temperature sensitivity coefficient of the sensor are three times larger than the common FBG sensors. The linearity coefficients of the FBG sensor are larger than 0.999, and the relative error of the repeatability of all sensor samples is less than 1%. Through the stability test on the actual bridge, it is revealed that the long-term stability of the sensor is excellent, and the maximum error is less than 1.5%. In addition, the proposed FBG strain sensors are used to conduct a shear strengthening experiment on a reinforced concrete (RC) beam to verify its working performance. The experimental results show that the strain change and crack propagation of the RC beam are well monitored by the sensors during the loading process.
提出了一种具有增强应变灵敏度的长标距光纤布拉格光栅（FBG）应变传感器，该传感器由两个T形金属块封装。简要描述了其制造方法，并且可以通过改变其封装方法来灵活调整应变灵敏度。进行了一系列实验来研究其封装及其传感特性。实验结果表明，该传感器的应变和温度灵敏度系数是普通FBG传感器的三倍。FBG传感器的线性系数大于0.999，所有传感器样品重复性的相对误差小于1%。通过在实际桥梁上的稳定性测试，表明该传感器的长期稳定性优异，最大误差小于1.5%。此外，所提出的FBG应变传感器用于对钢筋混凝土（RC）梁进行抗剪加固试验，以验证其工作性能。实验结果表明，在加载过程中，传感器能很好地监测RC梁的应变变化和裂缝扩展。
