Non-linear, axi-symmetric finite element analyses of a circumferentially cracked bar specimen

A review of the use of circumferentially cracked bar specimens for the measurement of fracture toughness has identified several areas where further information is required before a test method can be fully developed. An area of concern was the choice of J-integral function available in the literature for the specimen. This article compares the J-integral functions available in the literature with the Rice contour integral evaluated from the results of non-linear, axi-symmetric finite element analyses performed for a range of crack depths and material behaviour. The comparison enables the optimum function to be chosen. The finite element analyses also enable an improved limit load function for the specimen to be derived.