Investigation of the damage mechanisms for mode I delamination growth in foam core sandwich composites using acoustic emission

In this article, acoustic emission monitoring was used to identify different types of damage mechanisms which occur during delamination of sandwich structures. Features of the obtained acoustic emission signals and wavelet-based signal processing technique were utilized to discriminate failure mechanisms during the delamination test. Dominant damage mechanisms were classified based on their power spectral density in distinct frequency ranges and the energy distribution criterion in each component. The scanning electron microscopy was also employed to verify the results which were obtained from the acoustic emission investigation. It was concluded that frequency domain analysis and wavelet analysis are efficient tools for identification and discrimination of different damage mechanisms in sandwich structures.