PSI - Issue 68

Louka Eleftheria-Sotiria et al. / Procedia Structural Integrity 68 (2025) 894–900 Louka Eleftheria-Sotiria et al. / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 3. Strain distribution for the case of 2198-T3, 2 h EXCO pre-exposure and at nominal strain values (a) 8 %, (b) 14 %, and (c) 16 %.

Fig. 4. Strain distribution for the case of 2198-T3, 24 h EXCO pre-exposure and at nominal strain values: (a) 4 %, (b) 8 %, and (c) 9.2 %.

5. Comparison to experimental results The experimental stress-strain curves were compared with the model predicted curves for the AA2198 for two different ageing tempers (T3 and T8) and for two different EXCO exposure times (2 h and 24 h). The experimental and calculated results of the above ageing tempers are presented in Figs. 5 and 6, respectively. For the T3 temper (Fig. 5a) the maximum axial nominal strain value was reduced from 17.3 % to approximately 16 % after the 2 h EXCO exposure. No essential decrease of the mechanical strength properties (conventional yield stress R p0.2% & ultimate tensile strength R m ) was observed and the calculated values are in very good agreement with the experimental ones. For the T8 temper (Fig. 5b), the maximum axial nominal strain value was not essentially decreased after 2 h EXCO exposure. There is a very small decrease of the mechanical strength properties up to 4 %. The calculated values are in good agreement with the experimental values, while the uniform elongation A g values (nominal elongation up to R m ) are almost the same.