Fiber Bragg grating application to study an unmanned aerial system composite wing

Structural health monitoring consists of structural integrity assessment by means of data acquisition and analysis from on-board sensors. Fiber Bragg grating–based monitoring is increasingly attracting the scientific community working on structural health monitoring due to its multiple advantages such as electromagnetic immunity, negligible weight and size, and multiplexing availability. However, the integration of fiber optics within a structure still requires new procedures and signal treatment techniques for increasing technology reliability and exploiting its full potential. In this article, five embedded Fiber Bragg grating sensors are installed in an unmanned aerial system wing for correlating operational conditions with structural strain in real time. Sensor locations are determined by a finite element model accounting for manufacturing limitations of the fiber line. The developed Fiber Bragg grating system and processing techniques are used in static and dynamic tests showing the capacities of this powerful technology. The assessment includes deflection shape estimation, strain cycles counting, audible and visual strain alarms, aileron control based on strain levels, and structural resonance response detection.