Structural integrity analysis of notched ferritic steels operating within their ductile-to-brittle transition zone: An approach from Failure Assessment Diagrams and the Notch Master Curve

Abstract

This paper provides a structural integrity assessment methodology for the analysis of ferritic steels containing notch-type defects and operating within their ductile-to-brittle transition zone. The methodology, based on the use of Failure Assessment Diagrams and the novel concept of the Notch Master Curve, has been applied to 323 experimental results performed on four different steels (S275JR, S355J2, S460M and S690Q), six different notch radii (from 0 mm up to 2.0 mm), two different types of specimens (CT and SENB), and three different temperatures within the corresponding ductile-to-brittle transition zone. The results validate the proposed assessment methodology.

Application of EMC‐J criterion to fracture prediction of U‐notched polymeric specimens with nonlinear behaviour

“…For this matter, there are 2 main reasons to discuss: First, the failure analyses of brittle members are simple because the linear-elastic material behaviour assumption is considered while analysing. Moreover, similar researches have been published by Cicero and co-researchers, [13][14][15][16][17][18] in which the load bearing capacities have been studied for some notched ductile samples by means of TCD methodology. It is of great deal to perform failure analysis of ductile members with notches because there is a vast amount of new applications for ductile materials including aluminium alloys used in aerial vehicles, even though the analysis process of these materials which demonstrate elastic-plastic behaviour (especially the ductile metallic ones) is considerably more complicated than the analysis of brittle members with notches.…”

Out-of-plane constraint loss in three point bend specimens with notches

“…The material selected for the experimental programme was a 15mm thick structural steel plate of grade S460M [32] which has been used previously for studying notch effects on fracture [33,34]. Table 1 summarises the chemical composition of the material, performed by means of chemical emission spectroscopy, and Figure 2 shows the microstructure, which comprises alternate bands of pearlite and ferrite.…”

“…Table 2 summarises the tensile properties (defined at 0.2% plastic strain), Ultimate Tensile Strength (UTS), 𝜎 𝑦 and the strain at maximum load . 𝑒 𝑚𝑎𝑥 Fracture toughness properties of the same plate were determined in previous work [33,34] where the Master Curve Reference Temperature, T 0 [37,38], was calculated as -91.8 ºC. The fracture toughness as defined using the Master Curve approach includes a crack front length correction to account 𝐾 𝑚𝑎𝑡 for the microstructural weakest link effect in pre-cracked specimens.…”

“…The experimental fracture programme reported in this paper comprises 24 Single Edge Notch Bend (SENB) specimens containing notches instead of fatigue pre-cracks. This does not include the precracked specimens used to determine , reported in [33,34], or the notched specimens from the same 𝑇 0 papers. All specimens were machined from the same 15 mm thick plate from which the tensile specimens were machined, oriented parallel to the rolling direction, and notched in the throughthickness direction.…”

“…The work reported in [33,34] did not consider the effect of thickness on effective notch toughness 𝐵 . As the aim of the current work is to compare test results from specimens of two different 𝐾 𝜌 𝑚𝑎𝑡 thicknesses but with all other geometrical dimensions kept the same, 24 new tests have been 𝐵 specifically performed for this work, with the geometrical dimensions summarised in Table 3.…”