Acoustic emission features in textile reinforced thermoset and thermoplastic composites

In this work, the AE cluster analysis methodology was applied to investigate the peculiarities of the AE evolution and clustering in thermoset and thermoplastic reinforced 2D carbon and glass textiles. One thermoset (Epoxy) and two thermoplastic (Polyphenylene sulphide (PPS) and Polyether ether ketone (PEEK)) resins were considered. The epoxy was reinforced with balanced twill 2x2 carbon fabric and balanced twill 2x2 glass fabric. The PPS and the PEEK were reinforced with carbon plain weave textile. The comparison of the cumulative energy of AE events show that the thermoplastics reinforced composites have an early beginning of the damage and rapid saturation while a later beginning and more continuous growth of the damage was monitored in the textiles reinforced epoxy materials. The cluster analyses highlighted that the thermoset and thermoplastic reinforced composites have a net separation of the clusters. The crack monitoring in the thickness allowed the preliminary correlation of the transverse cracks in the PPS reinforced composite to the cluster containing AE events of low amplitude and low frequency.