PSI - Issue 37

Jesús Toribio et al. / Procedia Structural Integrity 37 (2022) 977–984 Jesús Toribio / Procedia Structural Integrity 00 (2021) 000 – 000

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3.3. Macro-Structural Integrity The concept of macro-structural integrity is applicable to real structural elements (at laboratory scale) or experimental specimens. Fig. 3 shows the fracture profile in a notched specimen of cold drawn pearlitic steel (Toribio and Ayaso, 2020 ), resembling John Ford’s Monument Valley .

Fig. 3. Fracture profile in sharply notched sample of a moderately cold drawn pearlitic steel (steel A3 that has undergone 3 cold drawing steps; specimen B with the maximum level of stress triaxiality/constraint) and Monument Valley in the USA (Monument Valley Profile; MVP ) .

3.4. Micro-Structural Integrity The concept of micro-structural integrity , coined by Toribio (2017a, 2017b ), refers to material’s microstructural level (Toribio, 2020a). Fig. 4 shows an enlarged pearlitic pseudocolony with anomalous interlamellar spacing.

Fig. 4. Micro-structural integrity: pearlitic pseudocolony in a heavily cold drawn pearlitic steel (x5.000)-

3.5. Nano-Structural Integrity Heavily cold drawn pearlitic steels exhibit an interlamellar spacing of about 0.030  m (30 nm) so that they can be considered as nanocomposites formed by alternate layers of ferrite (Fe) and cementite (Fe 3 C) and the novel concept of nanostructural integrity is adequate for nano-cracks at the nano-scale: the fractured Fe 3 C lamellae (Fig. 5a). Also in this scale of analysis, the objective would be destruction of the nanostructural integrity of SARS-CoV-2 (Fig. 5b).

Fig. 5. Nano-structural integrity: (a) enlarged view (x8000) of a pearlitic pseudocolony in a heavily cold drawn pearlitic steel; (b) SARS-CoV-2.