The strength and elastic property of PLA + graphite composites: experimental and theoretical analyses


  • Viktor Rubashevskyi KPI Igor Sikorskyi, Education and Research Institute of Mechanical Engineering, Department of Dynamics and Strength of Machines and Strength of Materials, Ukraine
  • Sergiy Shukayev KPI Igor Sikorskyi, Education and Research Institute of Mechanical Engineering, Department of Dynamics and Strength of Machines and Strength of Materials, Ukraine



3D printing, additive manufacturing, fused deposition modeling, PLA-Cg , PLA-CCF, mechanical properties, failure criteria


Background. The combination of additive technologies with reinforced materials opens up new vistas for creating lightweight and durable products having unique characteristics. Implementing these technologies into the production requires effective evaluation methods of the ultimate limit state of such products.

Objective. The article deals with the mechanical properties of samples, manufactured by the method of surfacing FDM with two polylactide-based thermoplastic threads: PLA-Cg+ with 5% layered graphite filling and PLA-CCF with 10% carbon fiber filling.

Methods. The impact of 3D printing process parameters, such as print orientation and layer thickness, on specimens' mechanical characteristics under conditions of tension and compression, has been experimentally researched.

Results. It is shown that both print orientation and layer thickness substantially influence specimens' mechanical properties of both materials. A comparative analysis of experimental data with calculations by failure criteria has been carried out: Tsai-Hill, Tsai-Wu, Hoffman, Mises, and maximum stresses.

Conclusions. The results of the tests proved that there is a significant influence of the studied parameters of the printing process on the mechanical characteristics of PLA + graphite specimens under both tension and compression. For the most part, samples with a smaller thickness have both a higher ultimate strength (limit of proportionality) and a greater relative elongation. It is defined that the best concurrence between experimental and calculated data for both materials can be achieved through using the generalized von Mises criterion.


  1. D.W. Martinez et al., “A comprehensive review on the application of 3D printing in the aerospace industry”, Key engineering materials, 913, pp. 27–34, 2022. DOI:
  2. K. Özsoy, B. Duman, and D.İ. Gültekin, “Metal part production with additive manufacturing for aerospace and defense indus-try”, Uluslararası Teknolojik Bilimler Dergisi, 11(3), pp. 201–210, 2019.
  3. D.K. Yadav, R. Srivastava and S. Dev, “Design & fabrication of ABS part by FDM for automobile application”, Materials Today: Proceedings, 26, pp. 2089–2093, 2020. DOI:
  4. L. Jiménez et al., “Polylactic acid (PLA) as a bioplastic and its possible applications in the food industry”, J Food Sci Nutr, 5(2), pp. 2–6, 2019. DOI:
  5. C.Y. Liaw and M. Guvendiren, “Current and emerging applications of 3D printing in medicine”, Biofabrication, 9(2), 024102, 2017. DOI:
  6. T.M. Medibew, “A comprehensive review on the optimization of the fused deposition modeling process parameter for better tensile strength of PLA-printed parts”, Advances in Materials Science and Engineering, 2022. DOI:
  7. Ł. Miazio, “Impact of print speed on strength of samples printed in FDM technology”, Agricultural Engineering, 23, 2019. DOI:
  8. Choi Young-Hyu et al., “Influence of Bed Temperature on Heat Shrinkage Shape Error in FDM Additive Manufacturing of the ABS-Engineering Plastic”, World Journal of Engineering and Technology, 04(03), pp. 186–92, 2016. DOI:
  9. A. Pandzic, D. Hodzic and A. Milovanovic, “Effect of Infill Type and Density on Tensile Properties of Plamaterial for FDM Process”, Annals of DAAAM & Proceedings, 30, 2019. DOI:
  10. Gebisa, Aboma Wagari, and Hirpa G. Lemu, “Influence of 3D Printing FDM Process Parameters on Tensile Property of Ultem 9085”, Procedia Manufacturing 30. pp. 331–38, 2019. DOI:
  11. Zhuo Xu, Rakel Fostervold and Nima Razavi, “Seyed Mohammad Javad. Thickness effect on the mechanical behavior of PLA specimens fabricated via Fused Deposition Modeling”, Procedia Structural Integrity, Vol. 33, pp. 571–577, 2021. DOI:
  12. Z. Yu et al., “Study on effects of FDM 3D printing parameters on mechanical properties of polylactic acid”, in Proc. IOP Con-ference Series: Materials Science and Engineering, Vol. 688, No. 3, p. 033026, November, 2019. DOI:
  13. J.F. Rodrıguez, J.P. Thomas and J.E. Renaud, “Design of fused-deposition ABS components for stiffness and strength”, J. Mech. Des., 125(3), pp. 545–551, 2003. DOI:
  14. M.G. Aruan Efendy and K.L. Pickering, “Comparison of strength and Young modulus of aligned discontinuous fibre PLA composites obtained experimentally and from theoretical prediction models”, Composite structures, 208, pp. 566–573, 2019. DOI:
  15. Y.E. Belarbi et al., “Effect of printing parameters on mechanical behaviour of PLA-flax printed structures by fused deposition modelling”, Materials, 14(19), 5883, 2021. DOI: 10.3390/ma14195883
  16. R.E. Przekop et al., “Graphite modified polylactide (PLA) for 3D printed (FDM/FFF) sliding elements”, Polymers, 12 (6), 1250. 2020. DOI:
  17. P.P. Lepihin and V.A. Romashhenko, “Methods and findings of stress-strain state and strength analyses of multilayer thick-walled anisotropic cylinders under dynamic loading (Review). Part 3. Phenomenological strength criteria”, Streng. Mater., 45(3), pp. 271–283, 2013.
  18. L.P. Kollar and G.S. Springer, Mechanics of composite structures, Cambridge: Cambridge University Press, 2003, 480 p. DOI:
  19. Failure Criteria in Fibre-Reinforced Polymer Composites: The World-Wide Failure Exercise. Amsterdam – Boston – Heidelberg – London – New York – Oxford - Paris – San Diego – San Francisco – Singapore – Sydney – Tokyo: Elsevier, 2004, 1255 p.
  20. L.P. Kollar and G.S. Springer, Mechanics of composite structures, Cambridge: Cambridge University Press, 2003, 480 p. DOI:
  21. O. Lampron et al., “Characterization of the non-isotropic tensile and fracture behavior of unidirectional polylactic acid parts manufactured by material extrusion”, Additive Manufacturing, 61, 103369, 2023. DOI:
  22. Plastmasy. Vyznachennia vlastyvostei pid chas roztiahuvannia. Chastyna 2. Umovy vyprobuvannia dlia plastmas, vyhotovle-nykh metodom formuvannia ta ekstruzii, DSTU EN ISO 527-2:2018 (EN ISO 527-2:2012, IDT; ISO 527-2:2012, IDT).
  23. ASTM D695−15, Standard Test Method for Compressive Properties of Rigid Plastics. American Society for Testing and Mate-rials: Philadelphia, PA, USA, 2015; Vol. 08.01, pp. 1–8.
  24. V.V. Rubashevskyi, S.M. Shukayev and A.M. Babak, “Effect of 3D Printing Process Parameters on the Mechanical Character-istics of Graphite-Modified Polylactide in Compression Tests”, Strength Mater, 2023. DOI:
  25. M. Kryshchuk, S. Shukayev and V.Rubashevskyi, “Modeling of Mechanical Properties of Composite Materials Under Differ-ent Types of Loads”, Nonlinear Mechanics of Complex Structures, Advanced Structured Materials, vol 157. Springer, Cham. 2021. DOI:
  26. V.D. Azzi and S.W. Tsai, “Anisotropic strength of composites”, Exp. Mech. 5(5), pp. 283–288, 1965.
  27. M.L. Benzeggagh, K. Khellil and T. Chotard, “Experimental determination of Tsai failure tensorial terms for unidirectional com-posite materials”, Compos. Sci. Technol. 55(2), pp. 145–156, 1995. DOI:
  28. S.W. Tsai and E.M. Wu, “A general theory of strength for anisotropic materials”, J. Compos. Mater. 5(1), pp. 58–80, 1971.
  29. O. Hoffman, “The brittle strength of orthotropic materials”, J. Compos. Mater., 1, pp. 200–206, 1967.
  30. R.V. Mises, “Mechanik der festen Körper im plastisch-deformablen Zustand. Nachrichten von der Gesellschaft der Wissen-schaften zu Göttingen”, Mathematisch-Physikalische Klasse, pp. 582–592, 1913.
  31. W.H. Yang, “A Generalized von Mises criterion for yield and fracture”, Trans. ASME, J. Appl. Mech. 47(2), pp. 297–300, 1980. DOI:



How to Cite

V. Rubashevskyi and S. Shukayev, “The strength and elastic property of PLA + graphite composites: experimental and theoretical analyses”, Mech. Adv. Technol., vol. 7, no. 2 (98), pp. 145–154, Sep. 2023.