Healing of low-velocity impact damage in vascularised composites

This research has sought to characterise damage formation and self-healing efficiency within vascularised carbon fibre reinforced polymer (CFRP) laminates over a range of low velocity impact energies. Using ultrasonic C-scanning and compression after impact (CAI) analysis, vascularised laminates were shown to conform to the same damage size to residual compression strength relationship established for conventional laminates. The damage tolerance level of the host laminate was carefully determined, an important consideration in selection of the most appropriate vascule spacing for a reliable self-healing system. The healing functionality imparted full recovery of post impact compression strength over the range of impact energies tested (2.5-20 J), via healing of matrix cracking and delamination damage. The successful implementation of this technology could substantially enhance the integrity, reliability and robustness of composite structures, whilst offering benefits through reduced operational costs and extended lifetimes. However, establishing the benefits of such novel systems to existing design criteria is challenging, suggesting that bespoke design tools will be required to fully attain the potential benefits of self-healing technologies.