FBG array arrangement optimization for impact localization

Abstract A method to optimize the arrangement of an fiber Bragg grating (FBG) array is described to address the need to improve the accuracy of impact localization for aerospace vehicles. The sensitive area of the FBG, which is approximately elliptical, is analyzed using finite element simulation and experimental measurement. Based on this analysis, three optimized FBG sensing arrangements are proposed to improve the coverage of the FBG sensitive area at the center, located on the side and corner positions of an experimental test sample when subject to an impact. By employing the inverse problem analysis method in multiple repetitions of impact localization experiments, the accuracy of impact localization is improved from 74% with the traditional 4-corner arrangement to 84%, 88%, and 91% respectively for the three arrangements, demonstrating the effectiveness of the optimized FBG array arrangement method.