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Real Time Extraction of TOA from Overlapped AE Waves

AVIK KUMAR DAS, CHRISTOPHER K. Y. LEUNG

Abstract


Time of Arrival (TOA) detection is essential successful Acoustic Emission (AE) based structural health monitoring (SHM) system. During high burst rate results AE waves could overlap. AE waves shows similar narrowband, low frequency content thus overlapping of AE waves leads to overlap in both in time and frequency. As a result, the TOA information is lost in the coda of the previous wave and cannot be (reliably) detected by conventional techniques. In this paper, the problem was addressed through creation of a) Wave (Overlapping) Identification (WI) b) Wave Cleaning (WC) c) Arrival Detection (AD) approaches. In this paper, specifically the Wave Detection and Wave Cleaning approaches are introduced and described in detail. 3D Fingerprinting is meticulously designed to exploit wave arrival characteristics thus autogenously identifying the overlapping of waves for completing the WI system. Positive identification activates Wave Cleaning system which eradicates the influence of the Intersecting Wave using adaptive spectral subtraction (ASpS). Post removal of the TOA for the Intersected Wave was identified.


DOI
10.12783/shm2019/32098

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