Single crystal linear array for modal decomposition analysis

Abstract. The characterisation of a 16-element acoustic emission (AE) sensor manufactured using relaxor ferroelectric single crystal (RFSC) is reported. The sensor, a linear array for modal decomposition and analysis (LAMDA) based on piezoelectric transduction, can be used for AE-based damage detection in aerospace, land, and sea applications. The RFSC LAMDA sensor was mounted on a 1.6 mm thick aluminium plate, the response of the sensor to AE excitations produced via pencil lead break (PLB) was examined. PLB break-energy generated by various pencil lead-types were examined experimentally. HB pencil lead 3 mm long, 0.5 mm diameter, has a measured break-energy of 6.6 µJ. Experimentally, RFSC LAMDA was able to detect the 6.6 µJ PLB excitation at a distance of 200 mm across the 1.6 mm aluminium plate. Modal decomposition of modelled and measured signals produced by the RFSC LAMDA in response to A0 and S0 Lamb waves, in a 1.6 mm aluminium plate, are compared and found to be in good agreement.