Development of an experimental testbench for systems performance monitoring through optical fiber-based sensors

Development of an experimental testbench for systems performance monitoring through optical fiber-based sensors. The primary objective of this thesis is to demonstrate the versatility of fiber optic sensors manufactured through the Fiber Bragg Grating (FBG) process and, consequently, the potential to use the same hardware in diverse applications to monitor a complex system from multiple perspectives. It was necessary to decide which aeronautical system to emulate, considering the exploitation of the unique properties of fiber optics to achieve a result with significant relevance. The project was defined as a test bench serving as a technological demonstrator; this consisted of a dedicated support system and a cantilevered semi-wing section. The idea was to equip a wing with sensors for monitoring various parameters such as structural deformations, thermal anomalies, torque applied by an actuator and its position, sloshing, etc., and to design it to conduct experimental tests and measurements of different natures, ultimately validating the proposed solutions. The wing setup was prepared after defining the geometric dimensions of the test bench and all the components involved. Three slots were created on the wing's underside by removing the outer skin and hollowing out the structural core's filler material. Reinforcement ribs were manufactured using 3D printing technology to ensure adequate performance under structural stresses and were inserted at the openings. Subsequently, sensor installation was carried out. For deformation monitoring, four fiber lines were applied to the external skin; a specific bonding process was designed and validated, defining the type of resin to use, drying times, and all necessary precautions. A servo motor was chosen to detect the actuator position. The 3D printing method was once again utilized to create a support for measuring the compliance of the servo motor supports under constraint reactions, marking a new and innovative application. A deformable bag filled approximately halfway with water was inserted into the second slot to simulate tanks inside the wing, which was used to study the sloshing effect of fluid. The third slot was equipped with three sensors to detect temperature. They were positioned to map and locate the thermal source within the control volume. Experimental tests were then conducted to validate the proposed models by confirming the coherence of the collected data with the physical phenomena under examination. The results were satisfactory, achieving a transversal monitoring configuration of a complex system using a single technology. Further studies were conducted on the same test bench for data acquisition and processing, refining correlations with the physical measurements of interest. Leveraging knowledge acquired from other parallel projects within the PhotoNext group, it might be possible to integrate a real-time data acquisition and visualization system using a headset and a dedicated interface with the test bench.