Study of the influence of notch radii and temperature on the probability of failure: A methodology to perform a combined assessment

The fracture assessment of notched components based on cracked components approaches leads to over-conservative failure predictions. In the research literature, several approaches are proposed to overcome this problem using an apparent fracture toughness, KNmat. Nevertheless, most of these approaches are based on deterministic assumptions despite the large and variable scatter exhibited by KNmat for different notch radii (ρ) or temperatures (T). This paper proposes a methodology for deriving a probabilistic KNmat-ρ field including the effect of temperature on the failure of notched components. First, the theory of critical distances is applied to transform each apparent fracture toughness into the equivalent fracture toughness for ρ = 0. Then, the temperature is supposed to act as a scale effect in the Weibull cumulative distribution function of the equivalent fracture toughness, and the corresponding scale effect function is derived. Finally, the applicability of the proposed methodology is illustrated by an example using two ferritic-pearlitic steels: S275JR and S355J2.