PSI - Issue 68

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Boyu Li et al. / Procedia Structural Integrity 68 (2025) 59–65 B. Li et al. / Structural Integrity Procedia 00 (2025) 000–000

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For capillaries in MEAM polymers, irregular geometries with a lower area-to-perimeter ratio significantly increase the perimeter of their cross-section compared to a circular capillary with an equal cross-section area. In such a situation, the capillary forces have a more significant influence on the capillary effect. Consequently, the flow in an irregular capillary propagates a longer distance than the flow in a circular capillary with an equal cross-section area. 4. Conclusions The capillary flow has a critical role in the water diffusion process of AM polymer materials. However, simple circular capillaries do not adequately represent the complexity of real manufacturing-induced microstructures. So, the area-to-perimeter ratio can be utilised to quantify the complexity of capillary cross-sections. It was shown that capillaries with lower area-to-perimeter ratios had longer perimeters, leading to stronger capillary forces and greater flow extension. While this research offers some insights into this process, it is based on simplified geometric models and further studies with models obtained for printed specimens are necessary to capture real-world conditions better. References Caggiano, A., Said Schicchi, D., Mankel, C., Ukrainczyk, N., Koenders, E.A.B., 2018. A mesoscale approach for modeling capillary water absorption and transport phenomena in cementitious materials. Comput Struct 200, 1–10. Galpayage Dona, K.N.U., Du, E., Carlsson, L.A., Fletcher, D.M., Boardman, R.P., 2020. Modeling of water wicking along fiber/matrix interface voids in unidirectional carbon/vinyl ester composites. Microfluid Nanofluidics 24, 1–9. Li, B., Baxevanakis, K.P., Silberschmidt, V. V., 2024. Water diffusion in additively manufactured polymers: Analysis of the capillary effect. Micro 4, 281-294. Romero, P.E., Barrios, J.M., Molero, E., Bustillo, A., 2023. Tuning 3D-printing parameters to produce vertical ultra-hydrophobic PETG parts with low ice adhesion: A food industry case study. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 238, 750-758. Tekinalp, H.L., Kunc, V., Velez-Garcia, G.M., Duty, C.E., Love, L.J., Naskar, A.K., Blue, C.A., Ozcan, S., 2014. Highly oriented carbon fiber– polymer composites via additive manufacturing. Composites Science and Technology 105, 144–150. Upadhyay, R.K., Mishra, A.K., Kumar, A., 2020. Mechanical degradation of 3D printed PLA in simulated marine environment. Surfaces and Interfaces 21, 100778.