Engineering methods for the design and selection of materials against fracture

Abstract : Various approaches to the brittle fracture problem were reviewed and evaluated in terms of their applicability for satisfying ATAC's need for engineering procedures to be applied to materials selection and design criteria for the prevention of fracture in the future use of high-strength materials. Linear-elastic fracture mechanics technology was selected as the most applicable approach. A comprehensive review of the state of the art in fracture mechanics technology is presented. The fracture mechanics data available in the literature for high-strength steels, aluminum and titanium alloys were reviewed and evaluated with respect to their validity as fracture toughness parameters. All applicable fracture toughness data are tabulated. Additional fracture toughness data were generated in the program for HP-9-4-25 steel, 7079-T6 aluminum and 6Al-4V titanium. Crack growth rates as a function of the stress intensity were also determined for the steel and aluminum alloys. Engineering procedures and criteria for utilizing fracture mechanics technology were developed.