Frequency Features of Acoustic Emission on Failure Mechanisms in PE Self-reinforced Laminates

The purpose of this study is to investigate frequency features of acoustic emission (AE) on different failure mechanisms in PE self reinforced laminates. Three kinds of specimen pure LDPE resin, single fiber composites (SFC) and UHMWPE/LDPE unidirectional laminate were prepared to obtain desired damage modes. AE signals of matrix damage, interface debonding and fiber breakage can be activated by quasi-state tension of LDPE resin, [90] laminate and SFC respectively. Fast Fourier transform (FFT) was used to obtain frequency information of four different failure mechanisms including matrix plastic deformation (F1), matrix fracture (F2), interface debonding (F3) and fiber breakage (F4). The result revealed, frequency features were different on four failure mechanisms. Frequency distribution of Fl and F2 are below 100 kHz with peak frequency at about 40 kHz. Frequency distribution of F3 has two main regions 0-100 kHz and 200-300 kHz with peak frequency at about 40 kHz and 240 kHz respectively. Frequency of F4 also has two main regions 100-200 kHz and 400-500 kHz with peak frequency at about 150 kHz and 450 kHz respectively. The result can be applied to identify failure mechanism in PE self-reinforced composites.