NONLINEAR, AXISYMMETRICAL 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 deve loped. An area of concern was the choice of J-integral function availa ble in the literature for the specimen. This article compares the J-in tegral functions available in the literature with the Rice contour int egral evaluated from the results of non-linear, axi-symmetric finite e lement analyses performed for a range of crack depths and material beh aviour. The comparison enables the optimum function to be chosen. The finite element analyses also enable an improved limit load function fo r the specimen to be derived. (C) 1998 Elsevier Science Limited.