X-Ray Damage Characterisation in Self-Healing Fibre Reinforced Polymers

To realise autonomous healing in advanced composite structures a detailed understanding of the damage requiring repair is essential. Specifically, quantification of damage volume and through thickness damage mapping is key to ensuring that the delivery infrastructure can supply sufficient healing to critical locations whilst maximising coverage and minimising structural cost. Understanding how the damage is affected by and interacts with the delivery infrastructure is also crucial for optimising the structural performance. In this study micro X-ray computer tomography (CT) scanning was used to determine damage volume in quasi isotropic carbon fibre reinforced plastic (CFRP) laminates. The laminates incorporated a layer of hollow glass fibres (HGF) for the purpose of delivering a self-healing agent and were subject to low velocity impact. Post-impact analysis of the specimens was undertaken using ultrasonic C-scanning followed by micro X-ray CT scans. The scan results provided detailed information on the damage volume and location through the thickness of the laminate. Higher resolution CT scans also showed a limited interaction between the HGF and the impact damage indicating only a relatively small number of HGF are ruptured by the damage.