Technological advances have enabled the development of a number of optical fiber sensing\nmethods over the last few years. The most prevalent optical technique involves the use of fiber\nBragg grating (FBG) sensors. These small, lightweight sensors have many attributes that enable their\nuse for a number of measurement applications. Although much literature is available regarding\nthe use of FBGs for laboratory level testing, few publications in the public domain exist of their\nuse at the operational level. Therefore, this paper gives an overview of the implementation of FBG\nsensors for large scale structures and applications. For demonstration, a case study is presented in\nwhich FBGs were used to determine the deflected wing shape and the out-of-plane loads of a 5.5-m\ncarbon-composite wing of an ultralight aerial vehicle. The in-plane strains from the 780 FBG sensors\nwere used to obtain the out-of-plane loads as well as the wing shape at various load levels. The\ncalculated out-of-plane displacements and loads were within 4.2% of the measured data. This study\ndemonstrates a practical method in which direct measurements are used to obtain critical parameters\nfrom the high distribution of FBG sensors. This procedure can be used to obtain information for\nstructural health monitoring applications to quantify healthy vs. unhealthy structures.
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