Professor Mai has made important contributions to the fundamental understanding of the fracture behaviour of a broad range of advanced engineering materials. He has developed a unified crack-wake bridging model for coarse-grained ceramics, fibre cements and stitched composites, which accounts for subtle size and geomtry effects. His ingenious work on composite interfaces has led to the development of engineered composites with high strength and high toughness. Other achievements include studies on the energetic approach to fracture, the 'essential fracture work' technique, and composites manufacturing processes.