EFFECT OF SIDE WALLS ON THE THREE-POINT BENDING BEHAVIOR OF PLA AND PETG SANDWICH STRUCTURES MANUFACTURED BY FDM PRINTING

Öz

This study experimentally investigated the three-point bending behavior of Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol (PETG) sandwich structures produced using Fused Deposition Modeling (FDM) 3D printing technology, comparing configurations with and without side walls. Four material formulations were tested: PLA, PLA+, PETG, and Hyper PETG, with specimens manufactured using optimized printing parameters. The experimental findings demonstrated that side walls significantly enhanced the mechanical properties of sandwich structures, including flexural strength, flexural modulus, and energy absorption capacity. PLA+ specimens with side walls exhibited the highest overall performance, showing a 10.2% increase in maximum stress, 37.2% improvement in energy absorption, and 5.4% enhancement in elongation. PLA materials generally exhibited higher stiffness and strength values compared to PETG materials, with PLA+ achieving maximum stress values of 43.4 MPa. Distinct failure modes were observed, with specimens without side walls showing facesheet buckling and core-face delamination, while specimens with side walls demonstrated distributed failure patterns. These results emphasize that side walls serve as an effective design parameter for improving sandwich structure performance, and material selection should be tailored to application requirements.

Anahtar Kelimeler

• FDM
• PLA
• PETG
• Sandwich Structures
• Three-Point Bending
• Side-Wall Effect.

Kaynakça

1. 1. Ansari, A.A., Kamil, M., "Investigation of flexural properties in 3D printed continuous fiber-reinforced polymer composites", IOP Conference Series: Materials Science and Engineering, Vol. 1248, Issue 1, Pages 012070, 2022.
2. 2. Jasim, M., Abbas, T., Huayier, A., "The Effect of Infill Pattern on Tensile Strength of PLA Material in Fused Deposition Modeling (FDM) Process", Engineering and Technology Journal, Vol. 40, Issue 12, Pages 1-8, 2022. 3. Liu, W., Song, H., Wang, Z., Wang, J., Huang, C., "Improving mechanical performance of fused deposition modeling lattice structures by a snap-fitting method", Materials & Design, Vol. 181, Issue 108065, Pages 1-12, 2019.
3. 4. Iranmanesh, N., Yazdani Sarvestani, H., Ashrafi, B., Hojjati, M., "Beyond honeycombs: Core topology's role in 3D-printed sandwich panels", Materials Today Communications, Vol. 37, Issue 107548, Pages 1-15, 2023.
4. 5. Tunay, M., "Bending behavior of 3D printed sandwich structures with different core geometries and thermal aging durations", Thin-Walled Structures, Vol. 194, Issue 111329, Pages 1-18, 2024.
5. 6. De Castro, B.D., Magalhães, F.D.C., Panzera, T.H., Campos Rubio, J.C., "An Assessment of Fully Integrated Polymer Sandwich Structures Designed by Additive Manufacturing", Journal of Materials Engineering and Performance, Vol. 30, Issue 7, Pages 5031-5038, 2021.
6. 7. Enyan, M., Amu-Darko, J.N.O., Issaka, E., Abban, O.J., "Advances in fused deposition modeling on process, process parameters, and multifaceted industrial application: a review", Engineering Research Express, Vol. 6, Issue 1, Pages 012401, 2024.
7. 8. Aktepe, E., Aktepe, Ş., "PLA Ve Geri Dönüştürülmüş PET Filamentlerinin 3D FDM Baskıda Boyutsal Doğruluk Ve Geriçekilme Performansinin Karşılaştırılması", International Journal of 3D Printing Technologies and Digital Industry, Vol. 8, Issue 1, Pages 114-123, 2024.
8. 9. Doğru, A., Kaçak, M., Seydibeyoğlu, M.Ö., "Examination Of Mechanical Properties of Fasteners Produced With PET And PLA Materials In Extrusion-Based Additive Manufacturing Method", International Journal of 3D Printing Technologies and Digital Industry, Vol. 8, Issue 3, Pages 407-415, 2024.

9. 10. Demir, E., Duygun, İ.K., Bedeloğlu, A., "The Mechanical Properties of 3D-Printed Polylactic Acid/Polyethylene Terephthalate Glycol Multi-Material Structures Manufactured by Material Extrusion", 3D Printing and Additive Manufacturing, Vol. 11, Issue 1, Pages 197-206, 2024.
10. 11. Su, M., Ma, Q., Zhang, A., Wang, H., "Mechanical properties of sandwich structures with different webs enhanced by filling polyurethane foam and encasing rectangular tube", Materials Today Communications, Vol. 40, Issue 110058, Pages 1-12, 2024.
11. 12. Bishai, M., De, S., Adhikari, B., Banerjee, R., "A comprehensive study on enhanced characteristics of modified polylactic acid based versatile biopolymer", European Polymer Journal, Vol. 54, Issue 1, Pages 52-61, 2014.
12. 13. Caran, R., Yüksel, A., Ercan, N., Yunus, D.E., Bedeloğlu, A., "The flexural and compressive properties of sandwich composites with different 3D-printed core structures", Journal of Innovative Engineering and Natural Science, Vol. 1, Issue 1, Pages 1-15, 2023.
13. 14. Forés-Garriga, A., Gómez-Gras, G., Pérez, M.A., "Lightweight hybrid composite sandwich structures with additively manufactured cellular cores", Thin-Walled Structures, Vol. 191, Issue 111082, Pages 1-18, 2023.
14. 15. Gohar, S., Hussain, G., Ali, A., Ahmad, H., "Mechanical performance of honeycomb sandwich structures built by FDM printing technique", Journal of Thermoplastic Composite Materials, Vol. 36, Issue 1, Pages 182-200, 2023.
15. 16. Ilyas, R., Zuhri, M., Aisyah, H., Asyraf, M., Hassan, S., Zainudin, E., et al., "Natural Fiber-Reinforced Polylactic Acid, Polylactic Acid Blends and Their Composites for Advanced Applications", Polymers, Vol. 14, Issue 1, Pages 202, 2022.
16. 17. Karimi, A., Rahmatabadi, D., Baghani, M., "Various FDM Mechanisms Used in the Fabrication of Continuous-Fiber Reinforced Composites: A Review", Polymers, Vol. 16, Issue 6, Pages 831, 2024.
17. 18. Raj Mohan R, Venkatraman R., Raghuraman S, "Experimental analysis on density, micro-hardness, surface roughness and processing time of Acrylonitrile Butadiene Styrene (ABS) through Fused Deposition Modeling (FDM) using Box Behnken Design (BBD)", Materials Today Communications, Vol. 27, Issue 102353, Pages 1-12, 2021.
18. 19. Brejcha, V., Böhm, M., Holeček, T., Jerman, M., Kobetičová, K., Robert, Č., et al., "Comparison of Bending Properties of Sandwich Structures Using Conventional and 3D-Printed Core with Flax Fiber Reinforcement", Preprints, Vol. 1, Issue 1, Pages 1-20, 2024.
19. 20. Junaedi, H., Abd El-baky, M.A., Awd Allah, M.M., Sebaey, T.A., "Mechanical Characteristics of Sandwich Structures with 3D-Printed Bio-Inspired Gyroid Structure Core and Carbon Fiber-Reinforced Polymer Laminate Face-Sheet", Polymers, Vol. 16, Issue 12, Pages 1698, 2024.
20. 21. Hamad, K., Kaseem, M., Ayyoob, M., Joo, J., Deri, F., "Polylactic acid blends: The future of green, light and tough", Progress in Polymer Science, Vol. 85, Issue 1, Pages 83-127, 2018.
21. 22. Kartal, F., "Influence of Abrasive Water Jet Turning Operating Parameters on Surface Roughness of ABS and PLA 3D Printed Parts Materials", Engineering in Medicine and Engineering, Vol. 4, Issue 4, Pages 1-10, 2023.
22. 23. Sugiyama, K., Matsuzaki, R., Ueda, M., Todoroki, A., Hirano, Y., "3D printing of composite sandwich structures using continuous carbon fiber and fiber tension", Composites Part A: Applied Science and Manufacturing, Vol. 113, Issue 1, Pages 114-121, 2018.
23. 24. Andrzejewski, J., Gronikowski, M., Aniśko, J., "A Novel Manufacturing Concept of LCP Fiber-Reinforced GPET-Based Sandwich Structures with an FDM 3D-Printed Core", Materials, Vol. 15, Issue 15, Pages 5405, 2022.
24. 25. Kumar Patro, P., Kandregula, S., Suhail Khan, M.N., Das, S., "Investigation of mechanical properties of 3D printed sandwich structures using PLA and ABS", Materials Today: Proceedings, Vol. 1, Issue 1, Pages 1-8, 2023.
25. 26. Hao, W., Liu, Y., Zhou, H., Chen, H., Fang, D., "Preparation and characterization of 3D printed continuous carbon fiber reinforced thermosetting composites", Polymer Testing, Vol. 65, Issue 1, Pages 29-34, 2018.
26. 27. Nie, D., Kong, L., Zhang, Y., Qiu, X., Fu, Y., Gu, J., "Mechanical Performance and Failure Analysis of a 3D-Printed 'Continuous Layer–Lattice Layer–Continuous Layer' Sandwich Structure", Polymers, Vol. 15, Issue 21, Pages 4283, 2023.
27. 28. Penumakala, P.K., Santo, J., Thomas, A., "A critical review on the fused deposition modeling of thermoplastic polymer composites", Composites Part B: Engineering, Vol. 201, Issue 108336, Pages 1-15, 2020. 29. Pervaiz, S., Qureshi, T.A., Kashwani, G., Kannan, S., "3D Printing of Fiber-Reinforced Plastic Composites Using Fused Deposition Modeling: A Status Review", Materials, Vol. 14, Issue 16, Pages 4520, 2021.
28. 30. Rahim, T.N.A.T., Abdullah, A.M., Md Akil, H., "Recent Developments in Fused Deposition Modeling-Based 3D Printing of Polymers and Their Composites", Polymer Reviews, Vol. 59, Issue 4, Pages 589-624, 2019.
29. 31. Sucuoğlu, H.S., Böğrekci, İ., Demircioğlu, P., "Shape's Impact On Dimensional Precision In 3D Printed Components", International Journal of 3D Printing Technologies and Digital Industry, Vol. 9, Issue 1, Pages 1-8, 2025.
30. 32. Der, O., Başar, G., "Investigation Of The Effects Of Process Parameters On Machining Performance In Laser Cutting Of 3d-Printed PLA", International Journal of 3D Printing Technologies and Digital Industry, Vol. 9, Issue 1, Pages 9-20, 2025.
31. 33. Prayitno, G., Imaduddin, F., Ubaidillah, Arifin, Z., "Recent Progress of Fused Deposition Modeling (FDM) 3D Printing: Constructions, Parameters and Processings", IOP Conference Series: Materials Science and Engineering, Vol. 1096, Issue 1, Pages 012045, 2021.
32. 34. Der, O., Taşcı, M., Başar, G., Erçetin, A., "Intelligent Modeling and Prediction of CO₂ Laser Cutting Performance in FFF-Printed Thermoplastics Using Machine Learning Algorithms", Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2025.
33. 35. Der, O.," Multi-Output Prediction and Optimization of CO₂ Laser Cutting Quality in FFF-Printed ASA Thermoplastics Using Machine Learning Approaches", Polymers, Vol. 17, Issue 14, Pages 1–32, 2025.
34. 36. Der, O., Başar, G., & Kosunalp, S., "Parametric Evaluation of CO₂ Laser Cutting on Kerf Geometry and Bottom HAZ in 3D-Printed ABS Plates", E3S Web of Conferences, Vol. 638, Issue 1, 03007, 2025.