Strain Detection in Aerospace Composite Panels under Photonic Sensing Modules and Damage Accumulation

Abstract

The integration of structural health monitoring systems within aerospace structures represents a crucial paradigm shift toward predictive maintenance and enhanced operational safety. This paper presents a detailed investigation into the deployment of photonic sensing modules, specifically embedded and surface-mounted Fiber Bragg Grating sensors, for real-time strain tracking and damage accumulation characterization in advanced carbon fiber reinforced polymer composite panels. Through systematic experimental validation and theoretical modeling, we examine how microstructural degradation, including matrix cracking, delamination, and fiber breakage, alters the strain fields within the composite laminate. The photonic modules capture these localized disturbances via characteristic modifications in the reflected optical spectra, such as peak wavelength shifting, spectral broadening, and birefringence-induced peak splitting. By correlating these optical signatures with progressive mechanical loading, a high-fidelity mapping of damage propagation is achieved. The results demonstrate that photonic sensing not only offers superior spatial and temporal resolution compared to conventional resistive strain gauges but also provides critical early-warning indicators of structural failure prior to visible macroscopic degradation. Ultimately, this research establishes a robust methodology for the online assessment of aerospace structural integrity, laying the groundwork for self-sensing composite architectures in future aerospace platforms.