Electrical Resistance-Based Damage Sensing of Carbon Fiber-Reinforced Composites Using Simulation-Based Low-Velocity Impact Damage

Abstract

In this paper, finite element models were developed in ABAQUS for studying the influence of simulation-based low-velocity impact damage on the 4-probe electrical resistance of carbon fiber-reinforced polymer matrix (CFRP) laminates. The specimens in the current study were 16- and 32-ply AS4/3501-6 laminates with quasi-isotropic layup. Electrical resistance in the CFRP laminates was evaluated using a 4-step procedure. First, FE models were created in ABAQUS for simulating low-velocity impact using a quasi-static loading approach. Second, the stress results were imported into Matlab, and delamination analysis was performed using approach developed by de Moura and Marques [1]. The delamination predictions were plotted onto a discretized grid for each interface between plies with dissimilar fiber orientations. Third, 4-probe electrical FE models were developed in ABAQUS for specimens before and after impact using the concept of effective conducting thickness. The electrical conductivity was reduced in the through-thickness direction for damaged elements in order to represent the impact-induced delamination. Forth, a direct current of 10mA was applied to the electrical models in order to determine the influence of the simulation-based lowvelocity impact delamination on 4-probe electrical resistance using top and oblique measurement planes. For the top measurement plane, source and sensing electrodes were placed in a single line on the top surface of the specimen. For the oblique measurement plane, positive source and sensing electrodes were placed on the top surface, whereas the negative source and sensing electrodes were located on the bottom surface of the specimen. Generally, the oblique resistance measurement was more sensitive to the impact damage compared to the top resistance measurement. In addition, the resistance of the 16-ply specimens was more greatly affected by the delamination compared to the 32-ply specimens. Electrical resistance predictions were compared to the experimental data.