Source location using an optimized microfiber coupler sensor based on modal acoustic emission method

Summary This paper demonstrates the application of an optimized microfiber coupler sensor (MFCS) to the source location with modal acoustic emission (MAE) method. First, based on analyzing the key influence factors of MAE method application, the package optimization of MFCS has been investigated. It is found that the best packaging length is from the groove end to the place where the 2 fibers just begin to fuse, which could achieve both, good completeness of acoustic emission signal wavelet transform and relative high sensitivity. Then, the linear source localization has been performed using the optimized MFCS. The arrival time of the acoustic emission signal is decided by the contour threshold of the wavelet transform to avoid the wave reflection from edge and mode conversion. The locating accuracy with different thresholds is analyzed. It indicates that the result agrees with the actual source position better when higher threshold is set. Furthermore, considering noise contamination and the frequency components completeness, the appropriate range of threshold is suggested to the location calculation. Finally, the favorable localization result proves that applying this optimized MFCS to the MAE source location strategy is quite feasible.