An acoustic emission-based characterisation of intrinsically healing fibre-reinforced polymer composites

In this research work, two configurations of intrinsically healing carbon fibre-reinforced polymer matrix composites (CFRP) are analysed. Non-localised damage states are created in these composites and the recovery of their flexural properties is analysed. The results show that the tangent and chord moduli are recovered in the composites with unidirectional fibre configuration, whereas they are not recovered in the composites with twill-weave fibre configuration. The results show that the fibre architecture plays a key role in the healability of the CFRP composites. Acoustic emission (AE) testing is used to analyse the damage progression in these composites and its subsequent effect on the healability. In this context, parameter-based data classification using k-means++ and signal-based analysis using continuous wavelet transform (CWT) are used. The results show that the multimode failure and excessive resin bleed in the twill-weave composites are responsible for their poor recovery of flexural moduli. Nevertheless, the results also show the potential of the unidirectional composites in the self-healing applications.