In situ wavenumber-frequency modal decomposition of acoustic emissions

A new acoustic sensing capability, consisting of a flexible high-density linear piezoelectric sensor array coupled to a high-bandwidth interrogation device, is developed and applied to in situ wavenumber-frequency modal decomposition of acoustic emissions in plates. An experimental assessment of the capability is undertaken using acoustic emissions generated by a ball-drop impact on aluminium and composite panels. A new method for acoustic source localisation based on this new sensor array is described, and it is shown to be more accurate than a conventional multilateration technique using single-point piezoelectric receivers. The potential of this new capability for acoustic emission detection, location and possible quantification is discussed.