Performance Analysis for CNT-Based SHM in Composite Structures

Abstract

This paper presents results from a recent set of experiments devised to benchmark performance of a novel carbon nanotube (CNT) based approach for SHM in composite structures. CNT were bonded to cured carbon-fiber laminates using surfacing film, with electrodes embedded at either end. Five of each specimen was then subjected 3 types of damage: impact, cut slots and 4-point bending. For each type of test, resistance measurements were across the CNT network following each damage step, and during the 4-point-bending tests data was also collected under static load in addition to the unloaded state. Results indicate that the CNT networks exhibited little to no resistance change under nominal operating conditions, however significant resistance increases could be measured following events that permanently affected the composite laminates. CNT-based SHM has the potential to be a sensitive and reliable “witness†style damage detection method, while only introducing < 20 g/m2 mass and < 100 μm in thickness.