Experimental and Numerical Investigation of the Effect of Aperture Angle on the Apparent Tensile Response of FDM 3D-Printed PLA Specimens

Khalil Zouaoui; Salah Amroune; Mohamed-Said Chebbah; Mohamed Slamani; Barhm Abdullah Mohamad

doi:10.2478/fas-2025-0008

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Experimental and Numerical Investigation of the Effect of Aperture Angle on the Apparent Tensile Response of FDM 3D-Printed PLA Specimens

Fatigue of Aircraft Structures

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By: Khalil Zouaoui , Salah Amroune , Mohamed-Said Chebbah , Mohamed Slamani and Barhm Abdullah Mohamad

Open Access

|Jul 2026

Figures & Tables

Specimen geometry and aperture-angle configurations: (a) solid (reference) specimen; (b) overall dog-bone dimensions of the test specimen, defined according to ISO 3167:2014(E), with gauge length L0, gauge width b, and thickness h; (c) detail of the gauge section showing the two through-thickness apertures of equal radius R1 and inter- center spacing d, with the angle θ measured between the inter-center line and the axis transverse to the loading direction; (d) the eight aperture orientations investigated (θ = 0°, 15°, 30°, 45°, 60°, 75°, 90° and 105°) together with the solid reference.

Specimens during and after printing. (Source: authors’ own work).

Tensile testing protocol. (Source: authors’ own work).

Loading and meshing parameters. (Source: authors’ own work).

All 27 specimens after tensile test. (Source: authors’ own work).

Stress–strain behavior in 27 experimental specimens. (Source: authors’ own work).

Comprehensive mechanical properties analysis: (a) σnom,max vs. Eapp scatter plot for all 27 specimens, (b) Mean σnom,max variation with aperture angle, (c) Percentage reduction in σnom,max relative to solid configuration, and (d) Mean Eapp variation with aperture angle. (Source: authors’ own work).

Finite element prediction of von Mises stress field and fracture at σnom,max for solid specimen. (Source: authors’ own work)

Comparison of experimental and FEA stress–strain curves for representative specimens: (a) Solid, (b) 0°, (c) 15°, (d) 30°, (e) 45°, (f) 60°, (g) 75°, (h) 90°, (i) 105°. (Source: authors’ own work).

Summary of experimental σnom,max results for all nine configurations_

θ	σ_nom,1 (MPa)	σ_nom,2 (MPa)	σ_nom,3 (MPa)	*Mean σ_nom,max* ± SD (MPa)**	A_net/A₀ (–)	Regime	*Mean σ_net,max* (MPa)**	% red. in σ_nom
Solid	28.24	25.51	27.96	27.23 ± 1.50	1.000	—	27.23	—
0°	24.48	23.87	22.65	23.67 ± 0.94	0.600	Two-hole-cut	39.45	+13.1
15°	21.87	23.19	21.68	22.25 ± 0.82	0.695	Two-hole-cut	32.01	+18.3
30°	24.12	23.92	25.94	24.66 ± 1.11	0.800	One-hole-cut	30.83	+9.4
45°	24.85	23.97	23.57	24.13 ± 0.65	0.800	One-hole-cut	30.16	+11.4
60°	25.97	26.27	25.52	25.92 ± 0.37	0.800	One-hole-cut	32.40	+4.8
75°	26.71	26.40	26.55	26.56 ± 0.15	0.800	One-hole-cut	33.20	+2.5
90°	27.55	27.65	27.08	27.42 ± 0.30	0.800	One-hole-cut	34.28	−0.7
105°	28.07	28.95	26.92	27.98 ± 1.01	0.800	One-hole-cut	34.98	−2.8

Representative specimens selected for FEA validation_ The representative specimen of each group is the one whose σnom,max lies closest to the group mean_

Aperture Angle	Specimen	*Specimen σ_nom,max* (MPa)**	*Group mean σ_nom,max* (MPa)**
Solid	SP3	27.96	27.23
0°	SP5	23.87	23.67
15°	SP7	21.87	22.25
30°	SP10	24.12	24.66
45°	SP14	23.97	24.13
60°	SP16	25.97	25.92
75°	SP21	26.55	26.56
90°	SP22	27.55	27.42
105°	SP26	28.07	27.98

Summary of Eapp results for all nine configurations_

Aperture Angle	E1 (MPa)	E2 (MPa)	E3 (MPa)	Mean (MPa)	SD (MPa)	R² (all)
Solid	1437.0	1442.2	1442.0	1440.40	2.96	>0.999
0°	1308.8	1411.1	1372.4	1364.08	51.61	>0.999
15°	1446.7	1483.5	1457.7	1462.64	18.87	>0.999
30°	1453.1	1436.2	1435.9	1441.75	9.86	>0.999
45°	1445.3	1448.0	1450.1	1447.77	2.43	>0.999
60°	1448.5	1454.7	1451.5	1451.56	3.10	>0.999
75°	1460.2	1408.6	1447.5	1438.76	26.86	>0.999
90°	1453.2	1466.0	1445.0	1454.72	10.59	>0.999
105°	1496.4	1501.4	1485.8	1494.49	7.97	>0.999
Overall Mean	—	—	—	1444.02	37.53	>0.999

Filament specifications and FDM print parameters held constant across all 27 specimens_

Parameter	Symbol	Value	Unit
Filament material	—	PLA, white	—
Filament diameter	d_f	1.75	mm
Filament density	ρ	1.24	g/cm³
Spool weight	—	1	kg
3D printer	—	Anycubic i3 Mega X	—
Nozzle temperature	T_n	200	°C
Build-plate temperature	T_b	60	°C
Layer height	h_l	0.20	mm
Wall thickness	t_w	1.20	mm
Infill density	ρ_inf	100	%
Infill / raster pattern	—	Rectilinear, ±45°	—
Print speed	v	50	mm/s

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DOI: https://doi.org/10.2478/fas-2025-0008 | Journal eISSN: 2300-7591

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Language: English

Submitted on: Apr 15, 2026

Accepted on: May 20, 2026

Published on: Jul 9, 2026

Published by: ŁUKASIEWICZ RESEARCH NETWORK – INSTITUTE OF AVIATION

In partnership with: Paradigm Publishing Services

Keywords:

Fused Deposition Modeling (FDM),

Abaqus,

Related subjects:

Introductions and overviews,

Engineering, other

© 2026 Khalil Zouaoui, Salah Amroune, Mohamed-Said Chebbah, Mohamed Slamani, Barhm Abdullah Mohamad, published by ŁUKASIEWICZ RESEARCH NETWORK – INSTITUTE OF AVIATION
This work is licensed under the Creative Commons Attribution 4.0 License.

AHEAD OF PRINT

Experimental and Numerical Investigation of the Effect of Aperture Angle on the Apparent Tensile Response of FDM 3D-Printed PLA Specimens

Figures & Tables

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Fig. 2.

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Fig. 9.

Summary of experimental σnom,max results for all nine configurations_

Representative specimens selected for FEA validation_ The representative specimen of each group is the one whose σnom,max lies closest to the group mean_

Summary of Eapp results for all nine configurations_

Filament specifications and FDM print parameters held constant across all 27 specimens_

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