Grey relational approach to investigate the physio-mechanical characteristics of 3D printed multi-material polyamide-carbon fibre and polyamide-glass fibre composite structures

Abstract

The study aims to evaluate the effects of infill pattern (IP) and layer proportion on the physico-mechanical performance of a 3D-printed polyamide-carbon fiber (PA-CF) and polyamide-glass fiber (PA-GF) multi-material composite (MMC). Additionally, the study integrates the Grey Relational Analysis (GRA) to assess the suitability of layer composition and infill patterns for enhancing composite properties. The results revealed that MMCs with dominant PA-CF layers exhibited enhanced stiffness and load transfer, whereas PA-GF-rich layer MMCs showed improved ductility and dimensional tolerance. Among all MMCs, samples fabricated with 75% PA-CF and 25% PA-GF layers at line and gyroid IP exhibited a uniform balance between mechanical performance and dimensional stability. The sample fabricated with line IP exhibited the highest density and lowest shrinkage of 1.16 g/cm³ and 0.22%, respectively, indicating stable compactness. Similarly, the sample with the gyroid IP composite exhibited a density of 1.05 g/cm³. The mechanical test revealed that the gyroid IP sample with a 75% PA-CF and 25% PA-GF layer composition showed the highest tensile and flexural strengths of 30.3 MPa and 34.3 MPa, respectively. The continuous load paths of the gyroid structure improve stress distribution and minimize stress concentrations, thereby enhancing energy absorption and delaying crack propagation. The developed MMC has the potential to be used for the fabrication of lightweight structural components, such as customized load-bearing parts and energy-absorbing structures, in automotive, aerospace and biomedical applications.

Keywords

multi-material polyamide 3D printing mechanical properties grey relational analysis

Get full access to this article

View all access options for this article.

References

Justen

Montakhab

Thomas

, et al. Thermoplastic material extrusion additive manufacturing with in-situ milling: a novel approach for shaping of ceramics. Open Ceram 2026; 25: 100881. https://doi.org/10.1016/j.oceram.2025.100881

Kothandaraman

Balasubramanian

Palaniyappan

, et al. Material extrusion techniques for biomedical applications: biomaterials and their performance – a review. Mater Today Commun 2025; 49: 113707. https://doi.org/10.1016/j.mtcomm.2025.113707

Zeng

Huo

, et al. Graphite anode with thick honeycomb architecture and high areal capacity fabricated via FDM 3D printing for lithium-ion batteries. Int J Electrochem Sci 2025; 20: 101219. https://doi.org/10.1016/j.ijoes.2025.101219

Petousis

Michailidis

Papadakis

, et al. Enhanced engineering and biocidal polypropylene filaments enabling melt reduction of AgNO3 through PVP agent: a scalable process for the defense industry with MEX additive manufacturing. Def Technol 2025; 44: 52–66. https://doi.org/10.1016/j.dt.2024.09.007

Arunkumar

Balaji

Radhika

, et al. Effect of infill pattern on mechanical properties of 3D printed PLA-Zn composites for drone frame structures: a topology optimization integrated application study. Results Eng 2025; 25: 104107. https://doi.org/10.1016/j.rineng.2025.104107

Tümer

Erbil

. Extrusion-based 3D printing applications of PLA composites: a review. Coatings 2021; 11: 390. https://doi.org/10.3390/coatings11040390

Chouhan

Raj Singh

Mudgal

. Optimization of mechanical properties of 3D printed ABS: a comparative study of response surface methodology and TOPSIS. J Polym Res 2026; 33: 36. https://doi.org/10.1007/s10965-025-04754-w

Sam-Daliri

Ghabezi

Steinbach

, et al. Experimental study on mechanical properties of material extrusion additive manufactured parts from recycled glass fibre-reinforced polypropylene composite. Compos Sci Technol 2023; 241: 110125. https://doi.org/10.1016/j.compscitech.2023.110125

Zhang

Fan

Liu

. Fused deposition modeling 3D printing of polyamide-based composites and its applications. Compos. Commun 2020; 21: 100413. https://doi.org/10.1016/j.coco.2020.100413

10.

Hussain

Charoo

Haq

MIU

. Mechanical performance of 3D printed functionally graded PETG: an experimental investigation. Next Mater 2025; 9: 101093. https://doi.org/10.1016/j.nxmate.2025.101093

11.

Al Rashid

Koç

. Additive manufacturing for sustainability, circularity and zero-waste: 3DP products from waste plastic bottles. Compos. Part C Open Access 2024; 14: 100463. https://doi.org/10.1016/j.jcomc.2024.100463

12.

Cicek

U. I

Johnson

A. A

. Multi-objective optimization of FDM process parameters for 3D-printed polycarbonate using Taguchi-based gray relational analysis. Int J Adv Manuf Technol 2025; 137: 3709–3725. https://doi.org/10.1007/s00170-025-15392-3

13.

Dua

Rashad

Spears

, et al. Applications of 3D-Printed PEEK via fused filament fabrication: a systematic review. Polymers 2021; 13: 4046. https://doi.org/10.3390/polym13224046

14.

Raguž

Berer

Holzer

, et al. Multi-material 3D printing of soft dielectric actuators with optimized electrodes. J Appl Polym Sci 2026; 143: e58024. https://doi.org/10.1002/app.58024

15.

Sorimpuk

Choong

Chua

B-L

. Thermoforming characteristics of PLA/TPU multi-material specimens fabricated with fused deposition modelling under different temperatures. Polymers 2022; 14: 4304. https://doi.org/10.3390/polym14204304

16.

Nasution

Hakim

Herianto

, et al. Flexural performance and interfacial bonding of PLA/ABS/HIPS composites in multi-nozzle 3D printing. J. Brazilian Soc. Mech. Sci. Eng 2025; 48: 47. https://doi.org/10.1007/s40430-025-06033-7

17.

Krishnanand

Taufik

. Tailoring flexibility and strength in 3D printed parts via multi-material co-extrusion technology, multiscale multidiscip. Model. Exp. Des 2025; 9: 36. https://doi.org/10.1007/s41939-025-01103-8

18.

Khatir

Bouiadjra

BAB

Belaili

, et al. Analysis of the mechanical properties of 3D prints using a PLA/TPU composite filament. Int J Adv Manuf Technol 2026; 142: 6245–6254. https://doi.org/10.1007/s00170-025-17279-9

19.

Kumar

Singh

Koloor

SSR

, et al. On laminated object manufactured FDM-printed ABS/TPU multimaterial specimens: an insight into mechanical and morphological characteristics. Polymers 2022; 14: 4066. https://doi.org/10.3390/polym14194066

20.

Chouhan

Singh

RKR

Mudgal

. Optimization of FDM printing parameters for high-speed fabrication of PLA-ABS Bi-layer laminate structures. J Thermoplast Compos Mater. 2026; 08927057261441528. https://doi.org/10.1177/08927057261441528

21.

Yilmaz

Gul

Coban

. Investigation of mechanical properties in layered multi-material 3D printing using commercial filaments: direct stacking of ABS, PA, and compatibilizing layers. J Vinyl Addit Technol 2026; 32: 484–498. https://doi.org/10.1002/vnl.70051

22.

Kumar

Singh

, et al. Multi material 3D printing of PLA-PA6/TiO2 polymeric matrix: flexural, wear and morphological properties. J Thermoplast Compos Mater 2020; 35: 2105–2124. https://doi.org/10.1177/0892705720953193

23.

Yilmaz

Okan

Eyri

, et al. Analyzing the influence of multimaterial 3D printing and postprocessing on mechanical and tribological characteristics. Macromol Mater Eng 2024; 309: 2300428. https://doi.org/10.1002/mame.202300428

24.

Wang

Tang

, et al. PLA-based composite panels prepared via multi-material fused filament fabrication and associated investigation of process parameters on flexural properties of the fabricated composite. Polymers 2024; 16: 109. https://doi.org/10.3390/polym16010109

25.

Rajesh Kannan

Mishra

Veeman

, et al. Investigation of physico-mechanical and flammability performance of 3D printed functionally graded polyamide carbon fibre and glass fibre multi-material composites. J Thermoplast Compos Mater. 2026; 08927057261434198. https://doi.org/10.1177/08927057261434198

26.

Sang

Wang

, et al. Thermo-oxidative ageing effect on mechanical properties and morphology of short fibre reinforced polyamide composites – comparison of carbon and glass fibres. RSC Adv 2017; 7: 43334–43344. https://doi.org/10.1039/C7RA07884F

27.

Salvi

Marzullo

Ostrowska

, et al. Thermal degradation of glass fibre-reinforced polyamide 6,6 composites: investigation by accelerated thermal ageing. Polymers 2025; 17: 509. https://doi.org/10.3390/polym17040509

28.

Charles

Ramkumaar

Azhagiri

, et al. FTIR and thermal studies on Nylon-66 and 30% glass fibre reinforced Nylon-66. J Chem 2009; 6: 909017–909033. https://doi.org/10.1155/2009/909017

29.

Bakirtzis

Ramani

Zhang

, et al. Simplified structure of the condensed phase of fire retarded PA6 nanocomposites in TGA as related flammability. Fire Saf J 2014; 69: 69–75. https://doi.org/10.1016/j.firesaf.2014.08.006

30.

Unnikrishnan

Zabihi

, et al. Multifunctional PA6 composites using waste glass fiber and green metal organic framework/graphene hybrids. Polym Compos 2022; 43: 5877–5893. https://doi.org/10.1002/pc.27002

31.

Yilmaz

. Comprehensive analysis of 3D printed PA6.6 and fiber-reinforced variants: revealing mechanical properties and adhesive wear behavior. Polym Compos 2024; 45: 1446–1460. https://doi.org/10.1002/pc.27865

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

1.02 MB

0.00 MB