An Application of Near Infra-Red Fibre Bragg Grating as Dynamic Sensor in SHM of Thin Composite Laminates

摘要

Vibration testing is an essential component in Structural Health Monitoring (SHM).It can provide vital information regarding the integrity of critical structure; forinstance, it can provide information on progressive failure monitoring ofcomposites structure in the aerospace industry. Over the past decade, there havebeen many successful researches showing extraordinary ability of Fiber Bragggrating (FBG) sensors as a dynamic sensor. Ability of acquiring both static anddynamic strain measurements, make FBG sensor as a good alternative to replace theconventional vibration sensors. In addition the physical size of FBG sensor providesgreater access to embed them in composite structures without affecting to anyproperties of the composite. However, in most applications to date, people haveused only the FBG with wavelength 1550 nm. Moreover, FBG sensors with thiswavelength are commonly use in industries such as telecommunications andmedical industries. However, there is an option of using near infra-red (NIR) FBGrange which comparably cheap in term of total system design. This paper details theuse of near infra-red (NIR) FBGs as dynamic sensors; a part of SHM system for themonitoring of the damages in a thin glass fiber composite plates. Results reveal thatthe NIR FBG range gives good response to an impact and; also to applied highfrequency vibrations.