Complexity of crack front geometry enhances toughness of brittle solids

This study investigates the impact of complex crack front geometry on the toughness of brittle solids. Using optical microscopy on various transparent, brittle materials (hydrogels and an elastomer), the researchers found that the critical strain energy required for crack propagation is directly proportional to the crack's geodesic length. This finding suggests that complex crack front geometries effectively enhance material toughness, challenging the assumptions of linear elastic fracture mechanics (LEFM) which typically models cracks as planar. The study highlights the significant gap in current 3D crack theory and has implications for material modeling and engineering testing.

Xinyue Wei, Chenzhuo Li, Cían McCarthy, John M. Kolinski