Composite Material Cracks Detection Using a Self‐Interference Long Period Grating Fiber Sensor

The purpose of this paper is to present a new method of detecting cracks that appear in the polymer matrix of a smart composite material using a self-interference long period grating (SILPG) fiber sensor setup. Strain and torsion deformations of the polymer matrix induced by the cracks effects on SILPG are exploited for crack detection. Different other features of the crack mechanism that induce a change in the SILPG status and response are identified. The response of SILPG fiber sensor under host composite material host crack action is investigated and simulated for defining the functional limits of the composite material. SILPG fiber sensor is considered as embedded in polymer matrix of composite material. SILPG is operated as the signal source of the smart composite material feedback loop.