Prediction of fracture toughness dependence on constraint parameter A using the weakest link model

A methodology for numerical prediction of fracture toughness dependence on the constraint parameter A is proposed. The weakest link model with stresses from J-A elastic-plastic asymptotic field is employed for prediction. Value of fracture toughness JC corresponding to small scale yielding constraint parameter ASSY is considered as JIC. Ratio of JC(A)/JIC is estimated as a function of A/ASSY using the Weibull shape parameter for the specimen material. Numerical prediction of fracture toughness values for three point bend specimens with different crack length demonstrates reasonable agreement with experimental measurements.