Non-Destructive Testing of In-Situ Activated Fiber Reinforced Composites

Abstract Conductive carbon fiber-reinforced polymer (CFRP) composites with self-sensing capabilities are highly suited for electrical impedance tomography (EIT) applications. Changes in the percolated fiber network can be tracked through corresponding variations in voltage and conductivity. Recent advancements in CFRP additive manufacturing have enabled the production of in-situ electrically activated composites via direct ink writing technique. This work presents the first implementation of EIT analysis on in-situ activated and additively manufactured CFRPs. Different sets of additively manufactured samples were investigated for EIT conductivity mapping. These included circular specimens with 16 electrodes, featuring central defects (holes or insulation). Conductivity maps of these specimens were compared to the fully conductive reference specimens allowing for the damage detection in the defective samples. EIT successfully captured the printing defects in these samples. The successful implementation of in-situ activated CFRPs will create new possibilities for real-time damage detection and allow for current injection and voltage measurements to be acquired from non-peripheral locations, addressing limitations commonly encountered in traditional EIT studies.