Tang Yongsheng, Wu Zhishen
School of Urban Rail Transportation, Soochow University, Suzhou 215137, China.
International Institute for Urban System Engineering, Southeast University, Nanjing 210096, China.
Sensors (Basel). 2016 Feb 25;16(3):286. doi: 10.3390/s16030286.
Brillouin scattering-based distributed optical fiber (OF) sensing technique presents advantages for concrete structure monitoring. However, the existence of spatial resolution greatly decreases strain measurement accuracy especially around cracks. Meanwhile, the brittle feature of OF also hinders its further application. In this paper, the distributed OF sensor was firstly proposed as long-gauge sensor to improve strain measurement accuracy. Then, a new type of self-sensing fiber reinforced polymer (FRP) bar was developed by embedding the packaged long-gauge OF sensors into FRP bar, followed by experimental studies on strain sensing, temperature sensing and basic mechanical properties. The results confirmed the superior strain sensing properties, namely satisfied accuracy, repeatability and linearity, as well as excellent mechanical performance. At the same time, the temperature sensing property was not influenced by the long-gauge package, making temperature compensation easy. Furthermore, the bonding performance between self-sensing FRP bar and concrete was investigated to study its influence on the sensing. Lastly, the sensing performance was further verified with static experiments of concrete beam reinforced with the proposed self-sensing FRP bar. Therefore, the self-sensing FRP bar has potential applications for long-term structural health monitoring (SHM) as embedded sensors as well as reinforcing materials for concrete structures.
基于布里渊散射的分布式光纤（OF）传感技术在混凝土结构监测方面具有优势。然而，空间分辨率的存在极大地降低了应变测量精度，尤其是在裂缝附近。同时，光纤的脆性特征也阻碍了其进一步应用。本文首先提出将分布式光纤传感器用作长标距传感器以提高应变测量精度。然后，通过将封装好的长标距光纤传感器嵌入到纤维增强聚合物（FRP）筋中，开发出一种新型的自传感FRP筋，并对其应变传感、温度传感和基本力学性能进行了试验研究。结果证实了其优异的应变传感性能，即具有令人满意的精度、重复性和线性度，以及出色的力学性能。同时，长标距封装不影响温度传感性能，便于进行温度补偿。此外，研究了自传感FRP筋与混凝土之间的粘结性能，以探讨其对传感的影响。最后，通过采用所提出的自传感FRP筋加固混凝土梁的静态试验，进一步验证了传感性能。因此，自传感FRP筋作为嵌入式传感器以及混凝土结构的增强材料，在长期结构健康监测（SHM）方面具有潜在的应用价值。
