IN-SITU CURE MONITORING OF 3D WOVEN COMPOSITES WITH A MULTIFUNCTIONAL CNT SENSOR

In-situ process monitoring is essential in defining optimal composite production procedures by tracking resin flow and cure kinetics. Due to their piezoresistive properties, it is possible to monitor such processes and deformations in composites by integrating carbon nanotubes (CNTs) into structures. Hence, incorporating CNTs dispersions into any surface can be utilized as strain sensors. The dispersion of CNTs can be improved by combining them with other nanomaterials, such as cellulose nanocrystals (CNCs). The CNTs:CNCs dispersion can be applied to fabrics for deformation detection applications using screen printing technology. Here, the CNTs:CNCs dispersion was screen printed onto 3D woven orthogonal fabrics as multi-sensors for both cure monitoring and followed by strain measurements under compressive loading. The conductive dispersions of CNTs:CNCs were initially studied for the rheology and stability at various CNTs to CNCs ratios. The print quality, thickness, and pattern effect have been investigated for the performance of CNTs:CNCs sensors, and for a two-layered sensor printing, the resistance was decreased by 73% compared to single-layered, meaning that the electrical conductivity was improved. Moreover, compression sensing was analyzed, and the curing degree was calculated as -9.3×10^-6