Some FBG-Based Damage Identification Techniques Applicable to Structural Health Monitoring for High-Speed Trains

Abstract

Fiber Bragg gratings (FBGs) have some advantages such as lightweight, small in size, immune to electro-magnetic interference, highly sensitive, quasi- or truly-distributed sensing of strain or temperature, etc. Therefore, FBGs have been promising sensors for structural health monitoring (SHM). In this paper, some typical damage identification techniques based on FBGs are presented, which were developed in our work in the last decade. They are damage identifications in modal strain space and in phase space, respectively, and the damage reconstruction (or damage imaging). The theories as well as the measurement techniques using FBGs for these approaches are outlined, along with several numerical and experimental validations. Finally, their potential applications in the SHM for high-speed trains are discussed.