Bridged and cohesive crack models for fracture in composite materials

The presentation revisits work done by the author and her collaborators over the last decade on two fundamental approaches for studying fracture in composite material systems, the bridged- and cohesive-crack models. Characteristic length scales and dimensionless groups that control fracture characteristics in finite size members and slender bodies, including the stability of crack growth, scaling tran-sitions in the mechanical response and modes of failure, are recalled and dis-cussed. Applications to composite materials for civil, naval and aeronautical structures are presented to highlight the significance of the bridged-crack model in the design of and with advanced composites. Recent results on the problem of multiple dynamic delamination fracture in multilayered systems are used to show how controlled fracture via material/structure design can be exploited to improve mechanical performance.