Comparison between Strain Measurements of Fiber Bragg Grating Sensors Attached Inside and Outside the Wing Structure

Structural health monitoring (SHM) systems are crucial for detecting damage to aircraft during flight and preventing major accidents. Strain and temperature measurements are particularly effective for identifying various types of structural damage in aircraft. Fiber Bragg Grating (FBG) sensors provide several operational and maintenance advantages over conventional sensors, such as strain gauges, for measuring strain and temperature during flight. However, installing these sensors inside the aircraft structure is economically inefficient due to maintenance difficulties and the necessity for installation during the composite aircraft manufacturing phase. To enhance operational efficiency, FBG sensors were mounted both inside and outside the wing structure of a composite aircraft. Strain data obtained from flight tests were compared at the same points where internal and external sensors were installed on the wing. The results demonstrated a high correlation between the strain data from internal and external sensors, suggesting that FBG sensors can be effectively installed on the exterior of the wing structure. This approach facilitates easier installation and maintenance with minimal performance loss.