Health Monitoring of a Filament Wound CFRP Composite Tank with Embedded FBG Sensors

摘要

These recent years, propellant tanks for rockets are being made with CFRP composites for weight saving. However, microscopic damages appear in the CFRP layers by internal pressure or sudden temperature change, and they may lead to the critical destruction. Thus, health monitoring technologies are important in order to keep the safety of the tanks. Fiber Bragg grating (FBG) sensors are often used for health monitoring systems, because the sensors are very sensitive, immune to electromagnetic interference, light in weight, and so on. In this research, small-diameter FBG sensors were embedded in CFRP layers in a filament wound composite tank. Real-time strain measurement of the tank during both cure process and pressure test was performed by measuring the wavelength shift of the reflection spectrum. Furthermore, the detection of microscopic damages was attempted by the observation of the deformation of the reflection spectrum.