Development and Characterization of 3D-Printed PETG Specimens Embedding Continuous Carbon Fiber Strain Sensors

Abstract:

Continuous monitoring of additively manufactured structures is essential for understanding their mechanical behavior and durability. This study investigates the electromechanical behavior of additively manufactured PETG specimens reinforced with continuous carbon fiber, with a particular focus on the influence of reinforcement geometry on strain-sensing performance. Specimens were fabricated using Fused Filament Fabrication and designed with four different reinforcement configurations: a reference single-layer layout, an extended-length reinforced region, a wider reinforced region, and a double-layer reinforcement. A total of twelve specimens were experimentally characterized. Electrical resistivity measurements were conducted under unloaded conditions and during bending induced by a low applied load of approximately 1.6 N. The initial electrical resistivity was found to depend on reinforcement geometry, with average values of approximately 523 Ω for the reference configuration, 888 Ω for the extended-length reinforcement, 1066 Ω for the wider reinforcement, and 285 Ω for the double-layer configuration. Under mechanical loading, the relative resistance variation remained below 0.6% for all specimens, indicating that the induced strain was very small. To further quantify strain sensitivity, the gauge factor was calculated for each configuration. Low average gauge factor values were obtained for the reference (K ≈ 0.1), extended-length (K ≈ 0.38), and wider (K ≈ 0.5) configurations. In contrast, the double-layer reinforcement exhibited a higher average gauge factor of approximately 2.24. These results indicate that reinforcement architecture affects the electromechanical sensitivity under low applied loads and offer insights for the design of multifunctional additively manufactured composite structures.

• Periodical: Key Engineering Materials (Volume 1047)
• Pages: 151-160
• Online since: April 2026
• Authors: Imi Ochana*, François Ducobu, Thomas Rainchon, Anthonin Demarbaix
• Keywords: Additive Manufacturing, Continuous Carbon Fiber, Electrical Resistivity, PETG Composite, Structural Health Monitoring

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