Applications of optical fiber sensors of SHM in infrastructures

Fiber optical (FO) sensors, especially fiber Bragg grating (FBG) sensors, have been considered as prominent high-durable local monitoring sensors and largely applied in structural health monitoring (SHM). However, it is still a big problem how to develop the feasible optical fiber sensors to fully meet the practical SHM for infrastructures. In this paper, some recent advances of fiber optical sensors developed and applied in bridge monitoring in mainland China, especially in Harbin Institute of Technology, are introduced. The main content include direct FBG-based sensors, indirect FBG-based sensors, FBG based smart structures, and their implementations in over 10 practical case studies of bridge monitoring, which include Yonghe River Bridge in Tianjin, Binzhou and Dongying Yellow River Bridges and Province, Songhua River Bridge, Hulan River bridge and NiutouShan bridge in Heilongjiang Province, Nanjing third Yangtze river Bridge, Maocaojie Bridge in Hunan Province, Erbian bridge in Sichuan and Guangyangdao Bridge in Chongqing, etc. Besides, F-P sensors have been used in Da-Fu-Si bridges and Wufu Bridges, etc. Finally, some directions of researches and applications have been recommended. Researches and practical applications show that FBG sensors are becoming one of the key sensors in longterm SHM instead of some conventional electrical sensors.