Structural Health Monitoring of Composite Laminate for Aerospace Applications via Embedded Panda Fiber Bragg Grating

In this paper, a polarization maintaining (PM) Panda fiber embedded in unidirectional Carbon Fiber Reinforced Polymer (CFRP) is investigated for sensing application in the field of aerospace composite materials. The Stress and Thermal distributions due to a uniaxial load applied and a temperature variation are evaluated. In particular, the effects of the resulted strains over propagating modes are analysed through a mode analysis approach, with a 2D-FEM model, by taking into account the residual Stress-Induced Birefringence of the Panda fiber. Then, the shifts of the Bragg wavelength of a uniform Fiber Bragg grating (FBG) are obtained via the Transfer Matrix Method (TMM) and the sensitivities to variation of strain and temperature are accurately calculated.