Design of experiment on smart materials: tensile test on 3D printed composites reinforced with continuous carbon fiber and resistivity detection

Abstract

Dans le cadre de la 28e "International ESAFORM Conference on Material forming", du 7 au 9 mai 2025 à Paestum en Italie. Abstract : "Structural Health Monitoring (SHM) refers to the process of continuously assessing the condition of materials and structures to detect damage, degradation, or performance changes over time. It uses sensors integrated into materials to monitor their behavior, enabling a better understanding of aging and structural integrity, which is particularly important in industries relying on advanced manufacturing methods. The aim of this study is to investigate the integration of SHM within additive manufacturing by exploring the relationship between the mechanical and electrical properties of Continuous Carbon Fiber Reinforced Thermoplastic Polymer composites. By embedding monitoring capabilities directly into the manufacturing process, this research seeks to overcome challenges related to material performance monitoring in industrial applications. Specimens compliant with ASTM D638 were fabricated using Fused Deposition Modeling (FDM) with coextrusion technology, which exposed the reinforcing carbon fibers at their ends for resistivity measurements. Carbon fiber’s electrical conductivity is leveraged to study variations in resistivity under mechanical stress. Three key variables were examined: carbon fiber filling patterns (U-shaped and W-shaped), the number of fiber layers, 2 or 4, and matrix filling densities, 10% or 30%. Tensile tests, conducted at 0.05 mm/s with a maximum tensile force of 2500 N, measured elongation, Young's modulus, resistivity and Gauge Factor (GF). The results provide critical insights into SHM integration in additive manufacturing. "