PSI - Issue 53

C.T. Duarte et al. / Procedia Structural Integrity 53 (2024) 299–308 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 7. Representative flexural stress-strain curves of unaged and aged specimens.

Fig. 8. Quantitative data as a function of hybridization: (a) flexural strength; (b) modulus

3.2 Effect of ageing on mechanical properties Tensile properties

Fig. 9 presents the quantitative tensile test data for both unaged and aged specimens. From Fig. 9a, it can be observed that only the A1P13A1 configuration showed a significant increase in the tensile strength, of approximately 21% compared to the ABS. When compared to the PLA, the configuration that showed a significant variation in tensile strength was A5P5A5, with a decrease of approximately 17%. Among the multi-material cases, the A5P5A5 and A3P9A3 configurations did not show a significant variation between them, whereas these two, when compared to A1P13A1, exhibited variations of 23% and 16%, respectively. Among all aged cases, it was observed that the only configuration significantly affected by seawater aging was A3P9A3, with a variation of approximately 20% compared to the same unaged group (Tables 3 and 5). This could be due to the variation of water uptake in between the deposited layers, this will be further discussed in the failure modes. Fig. 9b displays the Young's modulus data in a bar chart format. It can be observed that the stiffness of aged materials behaved similarly to the control group materials. There was a trend of increasing stiffness as the number of PLA layers increased. This could be explained by an increase in the crystallinity (Deroiné, M. et al. 2014). All multi material configurations showed an increase in stiffness compared to ABS. For instance, A5P5A5, A3P9A3, and A1P13A1 exhibited variations of approximately 17%, 34%, and 44%, respectively. However, when compared to PLA,