Impact localization system of composite structure based on recurrence quantification analysis by using FBG sensors

Abstract

Abstract Composite structures are susceptible to the damage induced by low velocity impacts (LVIs), thus the impact localization on composite structures is of great significance in the health monitoring of composite structures and preventing catastrophic failures. In this paper, an impact localization algorithm based on recurrence quantification analysis (RQA) by using Fiber Bragg Grating (FBG) sensors was proposed. Firstly, the response signals of LVIs were qualitatively analyzed by the graphical analysis method of recurrence plot (RP) and the regions of the LVIs were identified by comparing RQA measures including recurrence rate or determinism detected by different FBG sensors to determine which FBG sensors are the nearest. Then, the distances from LVIs to the nearest FBG sensors were estimated by curve fitting of recurrence rate and determinism. Finally, the location of the LVI predicted by recurrence rate and determinism can be obtained by genetic algorithm and be merged as the final results of impact localization according to their distances to the nearest FBG sensors. The impact localization system was established and verified on a composite plate with a 240 mm * 240 mm experiment area. The experiment results show that this impact localization method is effective in predicting the location of impact on composite structure with a low sampling rate interrogation module and small samples, the maximum and average errors are 38.41 mm and 25.27 mm, respectively.