Identification of failure modes in glass/polypropylene composites by means of the primary frequency content of the acoustic emission event

Tensile test were carried out on glass/polypropylene specimens made in-home, and acoustic emissions were recorded from these tests. Fibre orientation of each specimen was different in order to obtain preferred failure modes. The hypothesis is that each micro mechanical event will have one distinctive waveform as fingerprint. In order to differentiate the waveforms the primarily frequency is plotted on a power spectrum graph by means of a Fast Fourier Transformation. The primarily frequency from each power spectrum is then plotted against progress of test. The resulting graph showed clusters around well-defined frequencies. From the results it can be observed the existence of a relation between micro mechanical events and specific frequencies. (C) 2004 Elsevier Ltd. All rights reserved.