Multi-triggering and signal extraction for acoustic emissions monitoring

Acoustic Emission (AE) testing is a common practice in the monitoring of aerospace structures. Multi-receiving transducers and multi-triggering acquisition modality are used in the continuous monitoring of AE to overcome the problems of signal loss and to reduce the storage memory. Nevertheless, the stored samples are related to both AE signal and noise. A further reduction of storage memory is proposed in the paper by discarding the noise samples. The goal is ensured by analysis procedure that: (i) extracts the AE signal samples in efficient manner, and (ii) establishes the stop acquisition in adaptive manner without a priori information about the length of the AE signal. Experimental tests assess the effectiveness of the proposed analysis procedure to monitor all the AE events occurring inside concrete specimens, and to reduce the storage memory.