Impact localization on complex structures using FBG strain amplitude information

Localization of low energy impacts on carbon fiber composites is an important aspect of structural health monitoring since it creates subsurface damage which can significantly reduce the stiffness of a component. A novel impact localization method is proposed based on the strain amplitude measured by Fiber Bragg Grating (FBG) sensors. The algorithm is based on the relative placement of all sensors and the maximum strain amplitude measured by each sensor. This method requires minimal knowledge of the material or the structure and a minimum number of sensors. The algorithm showed good results on both simulated and experimental test cases of woven composite plates. It was found that a minimum of five FBG are necessary to accurately predict the impact location on a plate. The algorithm was also tested on a woven composite wing showing good localization along the span of the wing but higher errors along the chord length due to the nonlinearity in the measured strains.