Fiber Bragg Grating Strains to Obtain Structural Response of a Carbon Composite Wing

The objective of this study was to determine the deflected wing shape and the out-of-plane loads of a large-scale carbon-composite wing of an ultralight aerial vehicle using Fiber Bragg Grating (FBG) technology. The composite wing, subjected to concentrated and distributed loads, was instrumented with an optical fiber on its top and bottom surfaces positioned over the main spar, resulting in approximately 780 strain sensors bonded to the wings. The in-plane strains from the FBG sensors were used to obtain the out-of-plane loads as well as the wing shape at various load levels using NASA-developed real-time load and displacement algorithms. The calculated out-of-plane displacements and loads were generally within 4% of the measured data.