Locating Acoustic Emission Signals Due to Shock Impacts on a Carbon Fiber Sample Using Piezoelectric and Fiber Optic Sensors

Comparative tests related to locating acoustic emission (AE) signals due to shock impacts on a T700 carbon fiber sample were carried out. Piezoelectric acoustic emission transducers (AETs) and fiber-optic sensors (FOSs) were installed on the sample, forming rectangular location antennas measuring 360 x 280 mm. Strikes were delivered with balls weighing 10 and 18.5 g. Antennas consisting of four AET sensors and four FOS sensors and an antenna consisting of two AET sensors and two FOS sensors were organized. When using the antenna containing four FOS sensors, the impact on the sample was produced by a load weighing 530 g dropped from a height of 400 mm. AE signals were recorded by the SCAD-16.10 system with "floating" selection thresholds when the ball was dropped and during its repeated bounces. Then AE signal clusters were formed and recorded during the impact of loads. The arrival times of AE signals to the antenna sensors were calculated using the threshold method, the root mean square (RMS) deviation method and the two-interval method. It is shown that the maximum error in locating AE signals is observed when a steel ball with a diameter of 16 mm is dropped from a height of 300 mm and the minimum error is when using an electronic simulator.