A discussion of “An engineering methodology for constraint corrections of elastic–plastic fracture toughness – Part II: Effects of specimen geometry and plastic strain on cleavage fracture predictions” by C. Ruggieri, R.G. Savioli, R.H. Dodds [Eng. Fract. Mech. 146 (2015) 185–209]

Accurate Estimation of Brittle Fracture Toughness Deterioration in Steel Structures Subjected to Large Complicated Prestrains

“…In this subsection, the candidate mechanism is investigated based on a macroscopic model. It is reasonable that material damage progresses by plastic deformation and does not occur during elastic deformation [12,13]. Thus, the critical stress was divided into elastic and plastic components, as shown in Equation (12).…”

“…Bordet [10,11] postulated that the nucleation and growth of microcracks can be treated independently. In recent studies, Lei [12,13] suggested that an improvement in accuracy can be made by reconsidering the Weibull stress model based on the experience that brittle cracks never occur without yielding. However, there are some mandatory parameters that are difficult to determine in this improved model, which makes it difficult to apply this model in actual engineering applications.…”

A Statistical Model of Cleavage Fracture Toughness of Ferritic Steel DIN 22NiMoCr37 at Different Temperatures

“…Equations (1) and (2) are purely empirical and in fact conflict to each other. As analyzed in detail in Reference [20], due to the following relationship between KJc and Jc, KJc=EJc/(1−ν2) where the Weibull failure probabilities take the form of P=1−exp[−(JC−JminJ0)mJ]⇒P=1−exp[−(KJc2−Kmin2K02)mJ] P=1−exp[−(KJc−KminK0)mK]⇒P...…”

Statistical assessment of notch toughness against cleavage fracture of ferritic steels

“…Note that some of the highlighted fundamental defects are inherited by those modifications to the Beremin model, such as the incompliance with the physical assumption of plastic yielding as a prerequisite to cleavage fracture due to the adoption of a fixed‐value threshold stress σ th (including the case of σ th = 0), and the violation to the normality axiom of probability owing to the adoption of Equation 6a as the basic formulation of cumulative probability P . An example was elaborated in detail in the commentary to the work in Ruggieri et al In Table , the necessary corrections to the Beremin model are also provided to ensure the mathematical rigorousness and the physical compliance with the 5 assumptions below: The uniform spatial distribution of microcracks The weakest‐link postulate of brittle fracture Plastic yielding as a prerequisite for cleavage fracture The maximum tensile principal stress criterion for cleavage fracture (Equation 8) The power‐law distribution of microcrack size (Equation 9) …”

“…3,13 Recent studies 3,13,14 have identified the fundamental defects of the Beremin model, which are summarized in Table 1. Note that some of the highlighted fundamental defects are inherited by those modifications to the Beremin model, such as the incompliance with the physical assumption of plastic yielding as a prerequisite to cleavage fracture due to the adoption of a fixed-value threshold stress σ th (including the case of σ th = 0), [6][7][8][9][10] and the violation to the normality axiom of probability owing to the adoption of Equation 6a as the basic formulation of cumulative probability P. 10 An example was elaborated in detail in the commentary 15 to the work in Ruggieri et al 10 In Table 1, the necessary corrections to the Beremin model are also provided to ensure the mathematical rigorousness and the physical compliance with the 5 assumptions below:…”