The State of the Art in the Mechanics of Fracture.

Abstract : This report is a supplement to the annual technical report on the Science of Fracture project dated 30 November 1981 to the Air Force Office of Scientific Research and completes the work conducted on contract F49620-78-C-0101. The authors present their opinions as to the technical position of fracture mechanics within the framework of current military requirements, while simultaneously recognizing that this discipline is but one of several competing components of the overall technology base. The subject of continuum fracture mechanics has received a high level of attention. Through the concept of critical fracture toughness, advances in experimental stress analysis and mathematical analysis of failure have been translated into a practical and improved method for dealing with fracture. The authors advocate renewed support of basic research for new concepts, and suggest five areas with potential for high payoff, including characterization of the 3-D singularity at a crack tip, the fracture phenomenon in composite materials, the connection between Weibull and Griffith failure theories, and design of materials to resist fracture. Additional high payoff basic and applied research areas include specific topics in adhesive fracture, defect implications in electro-optical systems, interdisciplinary approach to life prediction, probabilistic methods for structural integrity, and computational mechanics.