Source location techniques in plate-like structures based on fiber coupler sensors

An improved optical fiber coupler sensor (OFCS) has been used for AE source location on plate-like structures with model acoustic emission (MAE) method, which provide a liner locating strategy with only one sensor. To identify flexural mode (A0) and longitude mode (S0) visibly, Gabor wavelet transform (GWT) has been introduced and applied on time-frequency analysis of AE signals. Based on MAE method, related location experiments are carried out by contrast with a piezoelectric transducer (PZT). Localization at 25 cm has been taken 13 times repeatedly and the results demonstrate the feasibility of the one sensor linear location scheme. Average relative errors and standard deviation of OFCS are 5.26% and 0.92 cm respectively, comparing to 7.06% and 1.03 cm of PZT. Results show that locating strategy by OFCS is more accurate than PZT, which provide the strong support for application of OFCS. Furthermore, a specific locating range has been investigated as distance between AE source and sensors are taken from 5 cm to 40 cm. The absolute location errors of OFCS between exact and evaluated distance are 0.38-2.31 cm, while absolute errors of PZT are 1.08-2.47 cm, which show that the locating performance of OFCS is somewhat better than PZT. Considering advantages of OFCS, it can be said OFCS is a great alternative sensor for AE source location in plate-like structures.