Strain monitoring and damage detection of a filament wound composite pressure tank using embedded fiber Bragg grating sensors

Composite pressure tanks are rapidly expanding in their range of use. However, for high pressure flammable or toxic gases, there is less confidence about their reliability. In this study, fiber Bragg grating (FBG) sensors embedded into a composite pressure tank monitored strain and detected damage. The sensor heads and fiber optic lines were protected with an acrylate recoating, adhesive films, PVC tubes and Teflon (R) film to survive under the harsh environment of the filament winding process. During the quasi-static loading test, the internal strain was measured with embedded FBG sensor arrays. In order to detect damage occurred during the test, impacts were applied on three different positions in each side by an impact hammer. The difference between damaged and undamaged sides in impact response was analyzed. An interrogation system using a wavelength-swept fiber laser (WSFL) was used for measuring strain, and an erbium-doped fiber amplifier (EDFA) laser source with a tunable Fabry-Perot filter was used for measuring impact response.