Modal Acoustic Emission Based Location Method in Honeycomb Core Sandwich Structure

We report on the acoustic emission signal propagation and modal acoustic emission (MAE) source location in aluminum honeycomb core sandwich structures. An experiment study supported by modal acoustic emission method is presented that symmetric and anti-symmetric mode of wave can be detected, location method based on virtual wave front is used to locate the acoustic emission source. A linear array of sensors receive signals from lead break and low velocity impact AE source, frequency response of sensed signal and wave velocity in different directions are obtained experimentally. The attenuation nature of different wave mode in the sandwich panel is monitored by measuring the signal amplitude at different distance measured from the AE source. Reduce the noise influence from acoustic emission signal by low-pass-filtering, anti-symmetric wave is selected in the lead beak and low velocity case, self-adaptive threshold value method is used to ensure the arrival time, the impact location is derived by a modified virtual wave front algorithm.