Multi-source acoustic emission localization technology research based on FBG sensing network and time reversal focusing imaging

A novel acoustic emission (AE) localization method and a detection system were proposed to complete multi-source AE localization based on time reversal focusing imaging and fiber Bragg grating sensors network. The principle of time reversal focusing was analyzed. Localization system was built with four FBG sensors. Signal demodulation was completed by narrow band laser edge filter technology. Shannon wavelet transform was used to extract specific frequency narrow band signal and calculate the modulus value. According to time reversal focusing model, multi-source AE imaging localization was implemented. The localization method and detection system were verified in 400 mm × 400 mm monitoring area which is on 6061 aluminum alloy plate. The experimental result indicates that this method and system can effectively realize localization and imaging, and the average error is 7.3 mm. The proposed detection system and localization method are provided for multi-source AE detection and localization with high accuracy.