PSI - Issue 51

J. Majko et al. / Procedia Structural Integrity 51 (2023) 160–165 J. Majko et al. / Structural Integrity Procedia 00 (2022) 000–000

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At the same time, significant differences in fracture patterns were observed (Fig. 4), which will need in-depth assessment upon obtaining SEM images.

(a)

(b)

Fig. 4. Differences in fracture patterns: (a) improperly stored material – A series; (b) properly stored material – B series.

Material storage and printing settings can have a significant impact on the specimen's damage mechanism. Additionally, the significant delamination observed in the second specimen (Fig. 4b) can considerably affect the material's fatigue properties, under similar mechanical characteristics, in terms of static loading and failure. Therefore, the authors are continuing their research, building on this initial study, in order to evaluate the impact of the different nozzle and printing bed temperatures on the achieved mechanical properties (tensile, flexural and so on) and failure mechanism/failure type of both properly and improperly stored nylon reinforced with chopped carbon fibres. 4. Conclusion Nylon is a hygroscopic material whose improper storage lead to problems with its processing in the 3D printing process. The reason is the overflowing of wet nylon through the nozzle heated to the melting temperature of dry nylon. As a result, the occurrence of printing inaccuracies and the formation of voids and stress concentrators can negatively affect the tensile strength. In this study, the authors attempted to adjust the nozzle temperature in such a way that material overflowing stopped. Subsequently, the possibility of printing was demonstrated, since the surface quality of