Interactions between propagating cracks and bioinspired self-healing vascules embedded in glass fibre reinforced composites

This study considers the embedment of a bioinspired vasculature within a composite structure that is capable of delivering functional agents from an external reservoir to regions of internal damage. Breach of the vascules, by propagating cracks, is a crucial pre-requisite for such a self-healing system to be activated. Two segregated vascule fabrication techniques are demonstrated, and their interactions with propagating Mode I and II cracks determined. The vascule fabrication route adopted played a significant role on the resulting laminate morphology which in-turn dictated the crack-vascule interactions. Embedment of the vascules did not lower the Mode I or II fracture toughness of the host laminate, with vascules orientated transverse to the crack propagation direction leading to significant increases in G_I and G_II through crack arrest. Large resin pockets were found to redirect the crack around the vascules under Mode II conditions, therefore, it is recommended to avoid this configuration for self-healing applications.