Speaker
Description
Reliable localisation of acoustic emission (AE) sources is one of the most critical inverse problems in non-destructive testing and structural health monitoring of engineering structures. Conventional AE localisation techniques often fail when applied to complex structures exhibiting wave dispersion, velocity variations, or geometric irregularities. Locating continuous AE signals, such as those generated by leakage, remains particularly challenging compared to localising short, burst-type emissions.
Time reversal (TR) signal processing offers an effective solution to these challenges. By enabling space-time wave focusing and partial reconstruction of the source signal, TR improves localisation accuracy. In this study, we employ the TR method to enhance the signal-to-noise ratio (S/N) and use cross-correlation functions (CCF) to identify the source location of continuous AE signals.
The proposed TR-based localisation approach was validated using an artificial AE source (a piezoelectric transducer emitting a continuous noise signal) applied to an aluminium plate with circular holes. The simulated leakage signal was recorded at various positions, time-reversed, and retransmitted into the structure. Accurate source localisation required detailed surface scanning around the initially estimated source area.
Experimental results demonstrate the potential of TR signal processing for practical engineering applications, particularly in the precise localisation of continuous AE sources.