A1 Journal article (refereed)
Microstructure and damage evolution in short carbon fibre 3D-printed composites during tensile straining (2025)
Almeida, J. H. S., Miettinen, A., Léonard, F., Falzon, B. G., & Withers, P. J. (2025). Microstructure and damage evolution in short carbon fibre 3D-printed composites during tensile straining. Composites Part B: Engineering, 292, Article 112073. https://doi.org/10.1016/j.compositesb.2024.112073
JYU authors or editors
Publication details
All authors or editors: Almeida, José Humberto S.; Miettinen, Arttu; Léonard, Fabien; Falzon, Brian G.; Withers, Philip J.
Journal or series: Composites Part B: Engineering
ISSN: 1359-8368
eISSN: 1879-1069
Publication year: 2025
Publication date: 12/12/2024
Volume: 292
Article number: 112073
Publisher: Elsevier
Publication country: United Kingdom
Publication language: English
DOI: https://doi.org/10.1016/j.compositesb.2024.112073
Publication open access: Openly available
Publication channel open access: Partially open access channel
Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/99561
Abstract
Short-fibre thermoplastic composites offer a balance between cost, processability, and performance, as well as providing a use for recycled fibres making them attractive in various industrial applications. However, the fibres tend to be misaligned due to their low aspect ratio, which can impact mechanical performance. This work examines the as-manufactured microstructure of a chopped carbon fibre-reinforced nylon composite made by material extrusion additive manufacturing in terms of fibre misalignment, void content, shape and distribution before going on to determine its effect on damage evolution under tensile straining by in-situ time-lapse synchrotron computed tomography (CT). To this end, CT scans have been acquired at various stages throughout straining. A high degree of fibre alignment is observed with ≈86% within 14◦ of the extrusion axis, giving a Krenchel orientation factor of 0.75. The time-lapse CT image sequence reveals that because the mean fibre length (≈98𝜇m.) is below the critical fibre length fibre fracture does not take place during plastic straining. Instead, failure occurs during straining from pre-existing voids and newly nucleated ones mainly located at fibre ends, their growth and coalescence. The experimental elastic modulus and strength are compared against the Cox-Krenchel and Kelly-Tyson analytical models that take into account fibre misalignment and length, which demonstrates that the fibre orientation is sufficient and future improvements in properties could be achieved by reducing the initial void content (≈2.3%) and increasing the length and volume fraction of the reinforcing fibres.
Keywords: 3D printing; computed tomography; microstructures; materials research
Free keywords: X-ray computed tomography; in-situ testing; 3D printing; fused filament fabrication; failure mechanisms
Contributing organizations
Ministry reporting: Yes
VIRTA submission year: 2024
Preliminary JUFO rating: 3
- School of Resource Wisdom (University of Jyväskylä JYU) JYU.Wisdom
- Nanoscience Center (Department of Physics PHYS, JYFL) (Faculty of Mathematics and Science) (Department of Chemistry CHEM) (Department of Biological and Environmental Science BIOENV) NSC
- Materials Physics (Department of Physics PHYS, JYFL)