Robust low-velocity impact localization algorithm on composite plate to dynamic operating conditions using fiber optic sensors

This paper introduces the impact localization algorithm on a composite stiffened plate using an array of four multiplexed fiber Bragg grating (FBG) sensors. For this algorithm, the impact signals are required as the reference data on the baseline points. In order to localize the impact event, the similarities between the obtained and each reference signal have to be evaluated. In this study, such similarities were assessed by calculating the root mean squared (RMS) values between the signals. In the first step, four RMS matrices from each sensor are obtained using the RMS values about each reference location on the test section as the elements. Then, the elements of each matrix are processed to extremely low value excepting a few number of elements with values near the minimum RMS values. From the element-by-element multiplications of these processed matrices, the final matrix could be obtained. Finally, the impact location could be predicted from the location of the high valued element in that matrix. This principle was validated from the localizations of non-baseline points. Also, to check the robustness of this algorithm to dynamic loading conditions, experimental investigations were performed. As a result, this suggested algorithm showed a reasonable localization performance.